diff --git a/blockpool/blockpool.go b/blockpool/blockpool.go
index c5af481a7..09b9e7b0b 100644
--- a/blockpool/blockpool.go
+++ b/blockpool/blockpool.go
@@ -7,8 +7,10 @@ import (
 	"time"
 
 	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/errs"
+	"github.com/ethereum/go-ethereum/event"
 	ethlogger "github.com/ethereum/go-ethereum/logger"
 	"github.com/ethereum/go-ethereum/pow"
 )
@@ -32,12 +34,15 @@ var (
 	blockHashesTimeout = 60 * time.Second
 	// timeout interval: max time allowed for peer without sending a block
 	blocksTimeout = 60 * time.Second
-	//
+	// timeout interval: max time allowed for best peer to remain idle (not send new block after sync complete)
 	idleBestPeerTimeout = 120 * time.Second
+	// duration of suspension after peer fatal error during which peer is not allowed to reconnect
+	peerSuspensionInterval = 300 * time.Second
+	// status is logged every statusUpdateInterval
+	statusUpdateInterval = 3 * time.Second
 )
 
-// config embedded in components, by default fall back to constants
-// by default all resolved to local
+// blockpool config, values default to constants
 type Config struct {
 	BlockHashesBatchSize       int
 	BlockBatchSize             int
@@ -48,26 +53,41 @@ type Config struct {
 	BlockHashesTimeout         time.Duration
 	BlocksTimeout              time.Duration
 	IdleBestPeerTimeout        time.Duration
+	PeerSuspensionInterval     time.Duration
+	StatusUpdateInterval       time.Duration
 }
 
 // blockpool errors
 const (
 	ErrInvalidBlock = iota
 	ErrInvalidPoW
-	ErrUnrequestedBlock
 	ErrInsufficientChainInfo
 	ErrIdleTooLong
+	ErrIncorrectTD
+	ErrUnrequestedBlock
 )
 
+// error descriptions
 var errorToString = map[int]string{
-	ErrInvalidBlock:          "Invalid block",
-	ErrInvalidPoW:            "Invalid PoW",
+	ErrInvalidBlock:          "Invalid block",              // fatal
+	ErrInvalidPoW:            "Invalid PoW",                // fatal
+	ErrInsufficientChainInfo: "Insufficient chain info",    // fatal
+	ErrIdleTooLong:           "Idle too long",              // fatal
+	ErrIncorrectTD:           "Incorrect Total Difficulty", // fatal
 	ErrUnrequestedBlock:      "Unrequested block",
-	ErrInsufficientChainInfo: "Insufficient chain info",
-	ErrIdleTooLong:           "Idle too long",
 }
 
-// init initialises all your laundry
+// error severity
+func severity(code int) ethlogger.LogLevel {
+	switch code {
+	case ErrUnrequestedBlock:
+		return ethlogger.WarnLevel
+	default:
+		return ethlogger.ErrorLevel
+	}
+}
+
+// init initialises the Config, zero values fall back to constants
 func (self *Config) init() {
 	if self.BlockHashesBatchSize == 0 {
 		self.BlockHashesBatchSize = blockHashesBatchSize
@@ -96,6 +116,12 @@ func (self *Config) init() {
 	if self.IdleBestPeerTimeout == 0 {
 		self.IdleBestPeerTimeout = idleBestPeerTimeout
 	}
+	if self.PeerSuspensionInterval == 0 {
+		self.PeerSuspensionInterval = peerSuspensionInterval
+	}
+	if self.StatusUpdateInterval == 0 {
+		self.StatusUpdateInterval = statusUpdateInterval
+	}
 }
 
 // node is the basic unit of the internal model of block chain/tree in the blockpool
@@ -122,31 +148,41 @@ type entry struct {
 type BlockPool struct {
 	Config *Config
 
-	// the minimal interface with blockchain
-	hasBlock    func(hash common.Hash) bool
-	insertChain func(types.Blocks) error
-	verifyPoW   func(pow.Block) bool
+	// the minimal interface with blockchain manager
+	hasBlock    func(hash common.Hash) bool // query if block is known
+	insertChain func(types.Blocks) error    // add section to blockchain
+	verifyPoW   func(pow.Block) bool        // soft PoW verification
+	chainEvents *event.TypeMux              // ethereum eventer for chainEvents
 
-	pool  map[string]*entry
-	peers *peers
+	tdSub event.Subscription // subscription to core.ChainHeadEvent
+	td    *big.Int           // our own total difficulty
+
+	pool  map[common.Hash]*entry // the actual blockpool
+	peers *peers                 // peers manager in peers.go
+
+	status *status // info about blockpool (UI interface) in status.go
 
 	lock      sync.RWMutex
 	chainLock sync.RWMutex
 	// alloc-easy pool of hash slices
 	hashSlicePool chan []common.Hash
 
-	status *status
-
-	quit    chan bool
-	wg      sync.WaitGroup
-	running bool
+	// waitgroup is used in tests to wait for result-critical routines
+	// as well as in determining idle / syncing status
+	wg      sync.WaitGroup //
+	quit    chan bool      // chan used for quitting parallel routines
+	running bool           //
 }
 
 // public constructor
+// after blockpool returned, config can be set
+// BlockPool.Start will call Config.init to set missing values
 func New(
 	hasBlock func(hash common.Hash) bool,
 	insertChain func(types.Blocks) error,
 	verifyPoW func(pow.Block) bool,
+	chainEvents *event.TypeMux,
+	td *big.Int,
 ) *BlockPool {
 
 	return &BlockPool{
@@ -154,15 +190,8 @@ func New(
 		hasBlock:    hasBlock,
 		insertChain: insertChain,
 		verifyPoW:   verifyPoW,
-	}
-}
-
-func severity(code int) ethlogger.LogLevel {
-	switch code {
-	case ErrUnrequestedBlock:
-		return ethlogger.WarnLevel
-	default:
-		return ethlogger.ErrorLevel
+		chainEvents: chainEvents,
+		td:          td,
 	}
 }
 
@@ -175,11 +204,13 @@ func (self *BlockPool) Start() {
 		return
 	}
 
+	// set missing values
 	self.Config.init()
+
 	self.hashSlicePool = make(chan []common.Hash, 150)
 	self.status = newStatus()
 	self.quit = make(chan bool)
-	self.pool = make(map[string]*entry)
+	self.pool = make(map[common.Hash]*entry)
 	self.running = true
 
 	self.peers = &peers{
@@ -188,16 +219,37 @@ func (self *BlockPool) Start() {
 			Errors:  errorToString,
 			Level:   severity,
 		},
-		peers:  make(map[string]*peer),
-		status: self.status,
-		bp:     self,
+		peers:     make(map[string]*peer),
+		blacklist: make(map[string]time.Time),
+		status:    self.status,
+		bp:        self,
 	}
-	timer := time.NewTicker(3 * time.Second)
+
+	// subscribe and listen to core.ChainHeadEvent{} for uptodate TD
+	self.tdSub = self.chainEvents.Subscribe(core.ChainHeadEvent{})
+
+	// status update interval
+	timer := time.NewTicker(self.Config.StatusUpdateInterval)
 	go func() {
 		for {
 			select {
 			case <-self.quit:
 				return
+			case event := <-self.tdSub.Chan():
+				if ev, ok := event.(core.ChainHeadEvent); ok {
+					td := ev.Block.Td
+					plog.DebugDetailf("td: %v", td)
+					self.setTD(td)
+					self.peers.lock.Lock()
+
+					if best := self.peers.best; best != nil {
+						if td.Cmp(best.td) >= 0 {
+							self.peers.best = nil
+							self.switchPeer(best, nil)
+						}
+					}
+					self.peers.lock.Unlock()
+				}
 			case <-timer.C:
 				plog.DebugDetailf("status:\n%v", self.Status())
 			}
@@ -218,6 +270,7 @@ func (self *BlockPool) Stop() {
 
 	plog.Infoln("Stopping...")
 
+	self.tdSub.Unsubscribe()
 	close(self.quit)
 
 	self.lock.Lock()
@@ -255,9 +308,14 @@ func (self *BlockPool) Wait(t time.Duration) {
 /*
 AddPeer is called by the eth protocol instance running on the peer after
 the status message has been received with total difficulty and current block hash
-Called a second time with the same peer id, it is used to update chain info for a peer. This is used when a new (mined) block message is received.
+
+Called a second time with the same peer id, it is used to update chain info for a peer.
+This is used when a new (mined) block message is received.
+
 RemovePeer needs to be called when the peer disconnects.
-Peer info is currently not persisted across disconnects (or sessions)
+
+Peer info is currently not persisted across disconnects (or sessions) except for suspension
+
 */
 func (self *BlockPool) AddPeer(
 
@@ -267,7 +325,8 @@ func (self *BlockPool) AddPeer(
 	requestBlocks func([]common.Hash) error,
 	peerError func(*errs.Error),
 
-) (best bool) {
+) (best bool, suspended bool) {
+
 	return self.peers.addPeer(td, currentBlockHash, peerId, requestBlockHashes, requestBlocks, peerError)
 }
 
@@ -281,12 +340,12 @@ AddBlockHashes
 
 Entry point for eth protocol to add block hashes received via BlockHashesMsg
 
-only hashes from the best peer are handled
+Only hashes from the best peer are handled
 
-initiates further hash requests until a known parent is reached (unless cancelled by a peerSwitch event, i.e., when a better peer becomes best peer)
-launches all block request processes on each chain section
+Initiates further hash requests until a known parent is reached (unless cancelled by a peerSwitch event, i.e., when a better peer becomes best peer)
+Launches all block request processes on each chain section
 
-the first argument is an iterator function. Using this block hashes are decoded from the rlp message payload on demand. As a result, AddBlockHashes needs to run synchronously for one peer since the message is discarded if the caller thread returns.
+The first argument is an iterator function. Using this block hashes are decoded from the rlp message payload on demand. As a result, AddBlockHashes needs to run synchronously for one peer since the message is discarded if the caller thread returns.
 */
 func (self *BlockPool) AddBlockHashes(next func() (common.Hash, bool), peerId string) {
 
@@ -297,7 +356,6 @@ func (self *BlockPool) AddBlockHashes(next func() (common.Hash, bool), peerId st
 	// bestpeer is still the best peer
 
 	self.wg.Add(1)
-
 	defer func() { self.wg.Done() }()
 
 	self.status.lock.Lock()
@@ -322,11 +380,11 @@ func (self *BlockPool) AddBlockHashes(next func() (common.Hash, bool), peerId st
 			return
 		}
 		/*
-		 when peer is promoted in switchPeer, a new header section process is launched
-		 as the head section skeleton is actually created here, it is signaled to the process
-		 so that it can quit
-		 in the special case that the node for parent of the head block is found in the blockpool
-		 (with or without fetched block)
+		 When peer is promoted in switchPeer, a new header section process is launched.
+		 Once the head section skeleton is actually created here, it is signaled to the process
+		 so that it can quit.
+		 In the special case that the node for parent of the head block is found in the blockpool
+		 (with or without fetched block), a singleton section containing only the head block node is created.
 		*/
 		headSection = true
 		if entry := self.get(bestpeer.currentBlockHash); entry == nil {
@@ -337,6 +395,7 @@ func (self *BlockPool) AddBlockHashes(next func() (common.Hash, bool), peerId st
 				block:   bestpeer.currentBlock,
 				hashBy:  peerId,
 				blockBy: peerId,
+				td:      bestpeer.td,
 			}
 			// nodes is a list of nodes in one section ordered top-bottom (old to young)
 			nodes = append(nodes, node)
@@ -344,7 +403,7 @@ func (self *BlockPool) AddBlockHashes(next func() (common.Hash, bool), peerId st
 		} else {
 			// otherwise set child section iff found node is the root of a section
 			// this is a possible scenario when a singleton head section was created
-			// on an earlier occasion this peer or another with the same block was best peer
+			// on an earlier occasion when this peer or another with the same block was best peer
 			if entry.node == entry.section.bottom {
 				child = entry.section
 				plog.DebugDetailf("AddBlockHashes: peer <%s>: connects to child section root %s", peerId, hex(bestpeer.currentBlockHash))
@@ -375,7 +434,7 @@ LOOP:
 		default:
 		}
 
-		// if we reach the blockchain we stop reading more
+		// if we reach the blockchain we stop reading further blockhashes
 		if self.hasBlock(hash) {
 			// check if known block connecting the downloaded chain to our blockchain
 			plog.DebugDetailf("AddBlockHashes: peer <%s> (head: %s) found block %s in the blockchain", peerId, hex(bestpeer.currentBlockHash), hex(hash))
@@ -412,10 +471,11 @@ LOOP:
 			// reached a known chain in the pool
 			if entry.node == entry.section.bottom && n == 1 {
 				/*
-					the first block hash received is an orphan in the pool
-					this also supports clients that (despite the spec) include <from> hash in their
+					The first block hash received is an orphan node in the pool
+
+					This also supports clients that (despite the spec) include <from> hash in their
 					response to hashes request. Note that by providing <from> we can link sections
-					without having to wait for the root block of the child section to arrive, so it allows for superior performance
+					without having to wait for the root block of the child section to arrive, so it allows for superior performance.
 				*/
 				plog.DebugDetailf("AddBlockHashes: peer <%s> (head: %s) found head block [%s] as root of connecting child section [%s] skipping", peerId, hex(bestpeer.currentBlockHash), hex(hash), sectionhex(entry.section))
 				// record the entry's chain section as child section
@@ -447,9 +507,8 @@ LOOP:
 
 	plog.DebugDetailf("AddBlockHashes: peer <%s> (head: %s): %v nodes in new section", peerId, hex(bestpeer.currentBlockHash), len(nodes))
 	/*
-	  handle forks where connecting node is mid-section
-	  by splitting section at fork
-	  no splitting needed if connecting node is head of a section
+	  Handle forks where connecting node is mid-section by splitting section at fork.
+	  No splitting needed if connecting node is head of a section.
 	*/
 	if parent != nil && entry != nil && entry.node != parent.top && len(nodes) > 0 {
 		plog.DebugDetailf("AddBlockHashes: peer <%s> (head: %s): fork after %s", peerId, hex(bestpeer.currentBlockHash), hex(hash))
@@ -461,10 +520,7 @@ LOOP:
 		self.status.lock.Unlock()
 	}
 
-	/*
-	  if new section is created, link it to parent/child sections
-	  and launch section process fetching blocks and further hashes
-	*/
+	// If new section is created, link it to parent/child sections.
 	sec = self.linkSections(nodes, parent, child)
 
 	if sec != nil {
@@ -477,11 +533,12 @@ LOOP:
 	self.chainLock.Unlock()
 
 	/*
-		if a blockpool node is reached (parent section is not nil),
+		If a blockpool node is reached (parent section is not nil),
 		activate section (unless our peer is demoted by now).
-		this can be the bottom half of a newly split section in case of a fork.
+		This can be the bottom half of a newly split section in case of a fork.
+
 		bestPeer is nil if we got here after our peer got demoted while processing.
-		in this case no activation should happen
+		In this case no activation should happen
 	*/
 	if parent != nil && !peerswitch {
 		self.activateChain(parent, bestpeer, nil)
@@ -489,9 +546,8 @@ LOOP:
 	}
 
 	/*
-	  if a new section was created,
-	  register section iff head section or no child known
-	  activate it with this peer
+	  If a new section was created, register section iff head section or no child known
+	  Activate it with this peer.
 	*/
 	if sec != nil {
 		// switch on section process (it is paused by switchC)
@@ -502,9 +558,9 @@ LOOP:
 				bestpeer.lock.Unlock()
 			}
 			/*
-			  request next block hashes for parent section here.
-			  but only once, repeating only when bottom block arrives,
-			  otherwise no way to check if it arrived
+			  Request another batch of older block hashes for parent section here.
+			  But only once, repeating only when the section's root block arrives.
+			  Otherwise no way to check if it arrived.
 			*/
 			bestpeer.requestBlockHashes(sec.bottom.hash)
 			plog.DebugDetailf("AddBlockHashes: peer <%s> (head: %s): start requesting blocks for section [%s]", peerId, hex(bestpeer.currentBlockHash), sectionhex(sec))
@@ -515,7 +571,7 @@ LOOP:
 		}
 	}
 
-	// if we are processing peer's head section, signal it to headSection process that it is created
+	// If we are processing peer's head section, signal it to headSection process that it is created.
 
 	if headSection {
 		plog.DebugDetailf("AddBlockHashes: peer <%s> (head: %s) head section registered on head section process", peerId, hex(bestpeer.currentBlockHash))
@@ -539,11 +595,13 @@ LOOP:
 /*
 	AddBlock is the entry point for the eth protocol to call when blockMsg is received.
 
-	It has a strict interpretation of the protocol in that if the block received has not been requested, it results in an error
+	It has a strict interpretation of the protocol in that if the block received has not been requested, it results in an error.
 
 	At the same time it is opportunistic in that if a requested block may be provided by any peer.
 
 	The received block is checked for PoW. Only the first PoW-valid block for a hash is considered legit.
+
+	If the block received is the head block of the current best peer, signal it to the head section process
 */
 func (self *BlockPool) AddBlock(block *types.Block, peerId string) {
 	hash := block.Hash()
@@ -564,7 +622,6 @@ func (self *BlockPool) AddBlock(block *types.Block, peerId string) {
 		if sender.currentBlock == nil {
 			plog.Debugf("AddBlock: add head block %s for peer <%s> (head: %s)", hex(hash), peerId, hex(sender.currentBlockHash))
 			sender.setChainInfoFromBlock(block)
-			// sender.currentBlockC <- block
 
 			self.status.lock.Lock()
 			self.status.values.BlockHashes++
@@ -573,6 +630,7 @@ func (self *BlockPool) AddBlock(block *types.Block, peerId string) {
 			self.status.lock.Unlock()
 		} else {
 			plog.DebugDetailf("AddBlock: head block %s for peer <%s> (head: %s) already known", hex(hash), peerId, hex(sender.currentBlockHash))
+			// signal to head section process
 			sender.currentBlockC <- block
 		}
 	} else {
@@ -591,7 +649,6 @@ func (self *BlockPool) AddBlock(block *types.Block, peerId string) {
 		sender.lock.Unlock()
 
 		if entry == nil {
-			// penalise peer for sending what we have not asked
 			plog.DebugDetailf("AddBlock: unrequested block %s received from peer <%s> (head: %s)", hex(hash), peerId, hex(sender.currentBlockHash))
 			sender.addError(ErrUnrequestedBlock, "%x", hash)
 
@@ -609,7 +666,7 @@ func (self *BlockPool) AddBlock(block *types.Block, peerId string) {
 	node.lock.Lock()
 	defer node.lock.Unlock()
 
-	// check if block already present
+	// check if block already received
 	if node.block != nil {
 		plog.DebugDetailf("AddBlock: block %s from peer <%s> (head: %s) already sent by <%s> ", hex(hash), peerId, hex(sender.currentBlockHash), node.blockBy)
 		return
@@ -645,9 +702,9 @@ func (self *BlockPool) AddBlock(block *types.Block, peerId string) {
 }
 
 /*
-  iterates down a chain section by section
-  activating section process on incomplete sections with peer
-  relinking orphaned sections with their parent if root block (and its parent hash) is known)
+  activateChain iterates down a chain section by section.
+  It activates the section process on incomplete sections with peer.
+  It relinks orphaned sections with their parent if root block (and its parent hash) is known.
 */
 func (self *BlockPool) activateChain(sec *section, p *peer, connected map[string]*section) {
 
@@ -666,8 +723,8 @@ LOOP:
 			connected[sec.top.hash.Str()] = sec
 		}
 		/*
-		  we need to relink both complete and incomplete sections
-		  the latter could have been blockHashesRequestsComplete before being delinked from its parent
+		  Need to relink both complete and incomplete sections
+		  An incomplete section could have been blockHashesRequestsComplete before being delinked from its parent.
 		*/
 		if parent == nil {
 			if sec.bottom.block != nil {
@@ -682,7 +739,7 @@ LOOP:
 		}
 		sec = parent
 
-		// stop if peer got demoted
+		// stop if peer got demoted or global quit
 		select {
 		case <-switchC:
 			break LOOP
@@ -693,7 +750,19 @@ LOOP:
 	}
 }
 
-// must run in separate go routine, otherwise
+// check if block's actual TD (calculated after successful insertChain) is identical to TD advertised for peer's head block.
+func (self *BlockPool) checkTD(nodes ...*node) {
+	for _, n := range nodes {
+		if n.td != nil {
+			plog.DebugDetailf("peer td %v =?= block td %v", n.td, n.block.Td)
+			if n.td.Cmp(n.block.Td) != 0 {
+				self.peers.peerError(n.blockBy, ErrIncorrectTD, "on block %x", n.hash)
+			}
+		}
+	}
+}
+
+// requestBlocks must run in separate go routine, otherwise
 // switchpeer -> activateChain -> activate deadlocks on section process select and peers.lock
 func (self *BlockPool) requestBlocks(attempts int, hashes []common.Hash) {
 	self.wg.Add(1)
@@ -720,13 +789,26 @@ func (self *BlockPool) getChild(sec *section) *section {
 func (self *BlockPool) get(hash common.Hash) *entry {
 	self.lock.RLock()
 	defer self.lock.RUnlock()
-	return self.pool[hash.Str()]
+	return self.pool[hash]
 }
 
 func (self *BlockPool) set(hash common.Hash, e *entry) {
 	self.lock.Lock()
 	defer self.lock.Unlock()
-	self.pool[hash.Str()] = e
+	self.pool[hash] = e
+}
+
+// accessor and setter for total difficulty
+func (self *BlockPool) getTD() *big.Int {
+	self.lock.RLock()
+	defer self.lock.RUnlock()
+	return self.td
+}
+
+func (self *BlockPool) setTD(td *big.Int) {
+	self.lock.Lock()
+	defer self.lock.Unlock()
+	self.td = td
 }
 
 func (self *BlockPool) remove(sec *section) {
@@ -735,7 +817,7 @@ func (self *BlockPool) remove(sec *section) {
 	defer self.lock.Unlock()
 
 	for _, node := range sec.nodes {
-		delete(self.pool, node.hash.Str())
+		delete(self.pool, node.hash)
 	}
 	if sec.initialised && sec.poolRootIndex != 0 {
 		self.status.lock.Lock()
@@ -744,6 +826,7 @@ func (self *BlockPool) remove(sec *section) {
 	}
 }
 
+// get/put for optimised allocation similar to sync.Pool
 func (self *BlockPool) getHashSlice() (s []common.Hash) {
 	select {
 	case s = <-self.hashSlicePool:
@@ -753,7 +836,6 @@ func (self *BlockPool) getHashSlice() (s []common.Hash) {
 	return
 }
 
-// Return returns a Client to the pool.
 func (self *BlockPool) putHashSlice(s []common.Hash) {
 	if len(s) == self.Config.BlockBatchSize {
 		select {
diff --git a/blockpool/blockpool_test.go b/blockpool/blockpool_test.go
index 411779057..9bcd72f04 100644
--- a/blockpool/blockpool_test.go
+++ b/blockpool/blockpool_test.go
@@ -5,10 +5,11 @@ import (
 	"time"
 
 	"github.com/ethereum/go-ethereum/blockpool/test"
-	"github.com/ethereum/go-ethereum/core/types"
-	"github.com/ethereum/go-ethereum/common"
 )
 
+// using the mock framework in blockpool_util_test
+// we test various scenarios here
+
 func TestPeerWithKnownBlock(t *testing.T) {
 	test.LogInit()
 	_, blockPool, blockPoolTester := newTestBlockPool(t)
@@ -44,48 +45,6 @@ func TestPeerWithKnownParentBlock(t *testing.T) {
 	blockPoolTester.checkBlockChain(blockPoolTester.refBlockChain)
 }
 
-func TestPeerPromotionByOptionalTdOnBlock(t *testing.T) {
-	test.LogInit()
-	_, blockPool, blockPoolTester := newTestBlockPool(t)
-	blockPoolTester.blockChain[0] = nil
-	blockPoolTester.initRefBlockChain(4)
-	peer0 := blockPoolTester.newPeer("peer0", 2, 2)
-	peer1 := blockPoolTester.newPeer("peer1", 1, 1)
-	peer2 := blockPoolTester.newPeer("peer2", 3, 4)
-
-	blockPool.Start()
-
-	// pool
-	peer0.AddPeer()
-	peer0.serveBlocks(1, 2)
-	best := peer1.AddPeer()
-	// this tests that peer1 is not promoted over peer0 yet
-	if best {
-		t.Errorf("peer1 (TD=1) should not be set as best")
-	}
-	best = peer2.AddPeer()
-	peer2.serveBlocks(3, 4)
-	peer2.serveBlockHashes(4, 3, 2, 1)
-	hashes := blockPoolTester.hashPool.IndexesToHashes([]int{2, 3})
-	peer1.waitBlocksRequests(3)
-	blockPool.AddBlock(&types.Block{
-		HeaderHash:       common.Bytes(hashes[1]),
-		ParentHeaderHash: common.Bytes(hashes[0]),
-		Td:               common.Big3,
-	}, "peer1")
-
-	blockPool.RemovePeer("peer2")
-	if blockPool.peers.best.id != "peer1" {
-		t.Errorf("peer1 (TD=3) should be set as best")
-	}
-	peer1.serveBlocks(0, 1, 2)
-
-	blockPool.Wait(waitTimeout)
-	blockPool.Stop()
-	blockPoolTester.refBlockChain[4] = []int{}
-	blockPoolTester.checkBlockChain(blockPoolTester.refBlockChain)
-}
-
 func TestSimpleChain(t *testing.T) {
 	test.LogInit()
 	_, blockPool, blockPoolTester := newTestBlockPool(t)
@@ -94,7 +53,7 @@ func TestSimpleChain(t *testing.T) {
 
 	blockPool.Start()
 
-	peer1 := blockPoolTester.newPeer("peer1", 1, 2)
+	peer1 := blockPoolTester.newPeer("peer1", 2, 2)
 	peer1.AddPeer()
 	peer1.serveBlocks(1, 2)
 	go peer1.serveBlockHashes(2, 1, 0)
@@ -114,7 +73,7 @@ func TestChainConnectingWithParentHash(t *testing.T) {
 
 	blockPool.Start()
 
-	peer1 := blockPoolTester.newPeer("peer1", 1, 3)
+	peer1 := blockPoolTester.newPeer("peer1", 3, 3)
 	peer1.AddPeer()
 	go peer1.serveBlocks(2, 3)
 	go peer1.serveBlockHashes(3, 2, 1)
@@ -134,7 +93,7 @@ func TestMultiSectionChain(t *testing.T) {
 
 	blockPool.Start()
 
-	peer1 := blockPoolTester.newPeer("peer1", 1, 5)
+	peer1 := blockPoolTester.newPeer("peer1", 5, 5)
 
 	peer1.AddPeer()
 	go peer1.serveBlocks(4, 5)
@@ -156,14 +115,17 @@ func TestNewBlocksOnPartialChain(t *testing.T) {
 	blockPoolTester.initRefBlockChain(7)
 	blockPool.Start()
 
-	peer1 := blockPoolTester.newPeer("peer1", 1, 5)
+	peer1 := blockPoolTester.newPeer("peer1", 5, 5)
+	blockPoolTester.tds = make(map[int]int)
+	blockPoolTester.tds[5] = 5
 
 	peer1.AddPeer()
 	go peer1.serveBlocks(4, 5) // partially complete section
 	go peer1.serveBlockHashes(5, 4, 3)
 	peer1.serveBlocks(3, 4) // partially complete section
+
 	// peer1 found new blocks
-	peer1.td = 2
+	peer1.td = 7
 	peer1.currentBlock = 7
 	peer1.AddPeer()
 	peer1.sendBlocks(6, 7)
@@ -172,7 +134,6 @@ func TestNewBlocksOnPartialChain(t *testing.T) {
 	go peer1.serveBlocks(5, 6)
 	go peer1.serveBlockHashes(3, 2, 1) // tests that hash request from known chain root is remembered
 	peer1.serveBlocks(0, 1, 2)
-	// blockPool.RemovePeer("peer1")
 
 	blockPool.Wait(waitTimeout)
 	blockPool.Stop()
@@ -188,16 +149,15 @@ func TestPeerSwitchUp(t *testing.T) {
 
 	blockPool.Start()
 
-	peer1 := blockPoolTester.newPeer("peer1", 1, 6)
-	peer2 := blockPoolTester.newPeer("peer2", 2, 7)
+	peer1 := blockPoolTester.newPeer("peer1", 6, 6)
+	peer2 := blockPoolTester.newPeer("peer2", 7, 7)
 
 	peer1.AddPeer()
 	go peer1.serveBlocks(5, 6)
 	go peer1.serveBlockHashes(6, 5, 4, 3) //
 	peer1.serveBlocks(2, 3)               // section partially complete, block 3 will be preserved after peer demoted
 	peer2.AddPeer()                       // peer2 is promoted as best peer, peer1 is demoted
-	go peer2.serveBlocks(6, 7)
-	// go peer2.serveBlockHashes(7, 6)       //
+	go peer2.serveBlocks(6, 7)            //
 	go peer2.serveBlocks(4, 5)            // tests that block request for earlier section is remembered
 	go peer1.serveBlocks(3, 4)            // tests that connecting section by demoted peer is remembered and blocks are accepted from demoted peer
 	go peer2.serveBlockHashes(3, 2, 1, 0) // tests that known chain section is activated, hash requests from 3 is remembered
@@ -216,8 +176,8 @@ func TestPeerSwitchDownOverlapSectionWithoutRootBlock(t *testing.T) {
 	blockPoolTester.initRefBlockChain(6)
 	blockPool.Start()
 
-	peer1 := blockPoolTester.newPeer("peer1", 1, 4)
-	peer2 := blockPoolTester.newPeer("peer2", 2, 6)
+	peer1 := blockPoolTester.newPeer("peer1", 4, 4)
+	peer2 := blockPoolTester.newPeer("peer2", 6, 6)
 
 	peer2.AddPeer()
 	peer2.serveBlocks(5, 6)                  // partially complete, section will be preserved
@@ -242,8 +202,8 @@ func TestPeerSwitchDownOverlapSectionWithRootBlock(t *testing.T) {
 	blockPoolTester.initRefBlockChain(6)
 	blockPool.Start()
 
-	peer1 := blockPoolTester.newPeer("peer1", 1, 4)
-	peer2 := blockPoolTester.newPeer("peer2", 2, 6)
+	peer1 := blockPoolTester.newPeer("peer1", 4, 4)
+	peer2 := blockPoolTester.newPeer("peer2", 6, 6)
 
 	peer2.AddPeer()
 	peer2.serveBlocks(5, 6)                  // partially complete, section will be preserved
@@ -269,8 +229,8 @@ func TestPeerSwitchDownDisjointSection(t *testing.T) {
 	blockPoolTester.initRefBlockChain(3)
 	blockPool.Start()
 
-	peer1 := blockPoolTester.newPeer("peer1", 1, 3)
-	peer2 := blockPoolTester.newPeer("peer2", 2, 6)
+	peer1 := blockPoolTester.newPeer("peer1", 3, 3)
+	peer2 := blockPoolTester.newPeer("peer2", 6, 6)
 
 	peer2.AddPeer()
 	peer2.serveBlocks(5, 6)            // partially complete, section will be preserved
@@ -297,8 +257,8 @@ func TestPeerSwitchBack(t *testing.T) {
 
 	blockPool.Start()
 
-	peer1 := blockPoolTester.newPeer("peer1", 2, 11)
-	peer2 := blockPoolTester.newPeer("peer2", 1, 8)
+	peer1 := blockPoolTester.newPeer("peer1", 11, 11)
+	peer2 := blockPoolTester.newPeer("peer2", 8, 8)
 
 	peer2.AddPeer()
 	go peer2.serveBlocks(7, 8)
@@ -328,9 +288,10 @@ func TestForkSimple(t *testing.T) {
 	delete(blockPoolTester.refBlockChain, 6)
 
 	blockPool.Start()
-
-	peer1 := blockPoolTester.newPeer("peer1", 1, 9)
-	peer2 := blockPoolTester.newPeer("peer2", 2, 6)
+	blockPoolTester.tds = make(map[int]int)
+	blockPoolTester.tds[6] = 10
+	peer1 := blockPoolTester.newPeer("peer1", 9, 9)
+	peer2 := blockPoolTester.newPeer("peer2", 10, 6)
 
 	peer1.AddPeer()
 	go peer1.serveBlocks(8, 9)
@@ -363,9 +324,10 @@ func TestForkSwitchBackByNewBlocks(t *testing.T) {
 	delete(blockPoolTester.refBlockChain, 6)
 
 	blockPool.Start()
-
-	peer1 := blockPoolTester.newPeer("peer1", 1, 9)
-	peer2 := blockPoolTester.newPeer("peer2", 2, 6)
+	blockPoolTester.tds = make(map[int]int)
+	blockPoolTester.tds[6] = 10
+	peer1 := blockPoolTester.newPeer("peer1", 9, 9)
+	peer2 := blockPoolTester.newPeer("peer2", 10, 6)
 
 	peer1.AddPeer()
 	go peer1.serveBlocks(8, 9)               //
@@ -378,7 +340,7 @@ func TestForkSwitchBackByNewBlocks(t *testing.T) {
 	peer2.serveBlocks(1, 2, 3, 4, 5)         //
 
 	// peer1 finds new blocks
-	peer1.td = 3
+	peer1.td = 11
 	peer1.currentBlock = 11
 	peer1.AddPeer()
 	go peer1.serveBlocks(10, 11)
@@ -410,8 +372,14 @@ func TestForkSwitchBackByPeerSwitchBack(t *testing.T) {
 
 	blockPool.Start()
 
-	peer1 := blockPoolTester.newPeer("peer1", 1, 9)
-	peer2 := blockPoolTester.newPeer("peer2", 2, 6)
+	blockPoolTester.tds = make(map[int]int)
+	blockPoolTester.tds[6] = 10
+
+	blockPoolTester.tds = make(map[int]int)
+	blockPoolTester.tds[6] = 10
+
+	peer1 := blockPoolTester.newPeer("peer1", 9, 9)
+	peer2 := blockPoolTester.newPeer("peer2", 10, 6)
 
 	peer1.AddPeer()
 	go peer1.serveBlocks(8, 9)
@@ -448,14 +416,17 @@ func TestForkCompleteSectionSwitchBackByPeerSwitchBack(t *testing.T) {
 
 	blockPool.Start()
 
-	peer1 := blockPoolTester.newPeer("peer1", 1, 9)
-	peer2 := blockPoolTester.newPeer("peer2", 2, 6)
+	blockPoolTester.tds = make(map[int]int)
+	blockPoolTester.tds[6] = 10
+
+	peer1 := blockPoolTester.newPeer("peer1", 9, 9)
+	peer2 := blockPoolTester.newPeer("peer2", 10, 6)
 
 	peer1.AddPeer()
 	go peer1.serveBlocks(8, 9)
 	go peer1.serveBlockHashes(9, 8, 7)
-	peer1.serveBlocks(3, 7, 8) // make sure this section is complete
-	time.Sleep(1 * time.Second)
+	peer1.serveBlocks(3, 7, 8)               // make sure this section is complete
+	time.Sleep(1 * time.Second)              //
 	go peer1.serveBlockHashes(7, 3, 2)       // block 3/7 is section boundary
 	peer1.serveBlocks(2, 3)                  // partially complete sections block 2 missing
 	peer2.AddPeer()                          //
@@ -463,8 +434,7 @@ func TestForkCompleteSectionSwitchBackByPeerSwitchBack(t *testing.T) {
 	go peer2.serveBlockHashes(6, 5, 4, 3, 2) // peer2 forks on block 3
 	peer2.serveBlocks(2, 3, 4, 5)            // block 2 still missing.
 	blockPool.RemovePeer("peer2")            // peer2 disconnects, peer1 is promoted again as best peer
-	// peer1.serveBlockHashes(7, 3)             // tests that hash request from fork root is remembered even though section process completed
-	go peer1.serveBlockHashes(2, 1, 0) //
+	go peer1.serveBlockHashes(2, 1, 0)       //
 	peer1.serveBlocks(0, 1, 2)
 
 	blockPool.Wait(waitTimeout)
diff --git a/blockpool/blockpool_util_test.go b/blockpool/blockpool_util_test.go
index 9ac996bca..be14fbae8 100644
--- a/blockpool/blockpool_util_test.go
+++ b/blockpool/blockpool_util_test.go
@@ -8,9 +8,10 @@ import (
 	"time"
 
 	"github.com/ethereum/go-ethereum/blockpool/test"
+	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/errs"
-	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/event"
 	"github.com/ethereum/go-ethereum/pow"
 )
 
@@ -38,6 +39,8 @@ type blockPoolTester struct {
 	blockChain        blockChain
 	blockPool         *BlockPool
 	t                 *testing.T
+	chainEvents       *event.TypeMux
+	tds               map[int]int
 }
 
 func newTestBlockPool(t *testing.T) (hashPool *test.TestHashPool, blockPool *BlockPool, b *blockPoolTester) {
@@ -48,8 +51,9 @@ func newTestBlockPool(t *testing.T) (hashPool *test.TestHashPool, blockPool *Blo
 		blockChain:        make(blockChain),
 		refBlockChain:     make(blockChain),
 		blocksRequestsMap: make(map[int]bool),
+		chainEvents:       &event.TypeMux{},
 	}
-	b.blockPool = New(b.hasBlock, b.insertChain, b.verifyPoW)
+	b.blockPool = New(b.hasBlock, b.insertChain, b.verifyPoW, b.chainEvents, common.Big0)
 	blockPool = b.blockPool
 	blockPool.Config.BlockHashesRequestInterval = testBlockHashesRequestInterval
 	blockPool.Config.BlocksRequestInterval = testBlocksRequestInterval
@@ -57,22 +61,24 @@ func newTestBlockPool(t *testing.T) (hashPool *test.TestHashPool, blockPool *Blo
 }
 
 func (self *blockPoolTester) Errorf(format string, params ...interface{}) {
-	fmt.Printf(format+"\n", params...)
+	// fmt.Printf(format+"\n", params...)
 	self.t.Errorf(format, params...)
 }
 
 // blockPoolTester implements the 3 callbacks needed by the blockPool:
-// hasBlock, insetChain, verifyPoW
-func (self *blockPoolTester) hasBlock(block []byte) (ok bool) {
+// hasBlock, insetChain, verifyPoW as well as provides the eventer
+// to subscribe to head insertions
+func (self *blockPoolTester) hasBlock(block common.Hash) (ok bool) {
 	self.lock.RLock()
 	defer self.lock.RUnlock()
-	indexes := self.hashPool.HashesToIndexes([][]byte{block})
+	indexes := self.hashPool.HashesToIndexes([]common.Hash{block})
 	i := indexes[0]
 	_, ok = self.blockChain[i]
-	fmt.Printf("has block %v (%x...): %v\n", i, block[0:4], ok)
+	// fmt.Printf("has block %v (%x...): %v\n", i, block[0:4], ok)
 	return
 }
 
+// mock insertChain relies on refBlockChain to determine block validity
 func (self *blockPoolTester) insertChain(blocks types.Blocks) error {
 	self.lock.Lock()
 	defer self.lock.Unlock()
@@ -80,13 +86,21 @@ func (self *blockPoolTester) insertChain(blocks types.Blocks) error {
 	var children, refChildren []int
 	var ok bool
 	for _, block := range blocks {
-		child = self.hashPool.HashesToIndexes([][]byte{block.Hash()})[0]
+		child = self.hashPool.HashesToIndexes([]common.Hash{block.Hash()})[0]
+		var td int
+		if self.tds != nil {
+			td, ok = self.tds[child]
+		}
+		if !ok {
+			td = child
+		}
+		block.Td = big.NewInt(int64(td))
 		_, ok = self.blockChain[child]
 		if ok {
-			fmt.Printf("block %v already in blockchain\n", child)
+			// fmt.Printf("block %v already in blockchain\n", child)
 			continue // already in chain
 		}
-		parent = self.hashPool.HashesToIndexes([][]byte{block.ParentHeaderHash})[0]
+		parent = self.hashPool.HashesToIndexes([]common.Hash{block.ParentHeaderHash})[0]
 		children, ok = self.blockChain[parent]
 		if !ok {
 			return fmt.Errorf("parent %v not in blockchain ", parent)
@@ -108,7 +122,6 @@ func (self *blockPoolTester) insertChain(blocks types.Blocks) error {
 		}
 		if ok {
 			// accept any blocks if parent not in refBlockChain
-			fmt.Errorf("blockchain insert %v -> %v\n", parent, child)
 			self.blockChain[parent] = append(children, child)
 			self.blockChain[child] = nil
 		}
@@ -116,6 +129,7 @@ func (self *blockPoolTester) insertChain(blocks types.Blocks) error {
 	return nil
 }
 
+// mock soft block validation always succeeds
 func (self *blockPoolTester) verifyPoW(pblock pow.Block) bool {
 	return true
 }
@@ -124,12 +138,12 @@ func (self *blockPoolTester) verifyPoW(pblock pow.Block) bool {
 func (self *blockPoolTester) checkBlockChain(blockChain map[int][]int) {
 	self.lock.RLock()
 	defer self.lock.RUnlock()
-	for k, v := range self.blockChain {
-		fmt.Printf("got: %v -> %v\n", k, v)
-	}
-	for k, v := range blockChain {
-		fmt.Printf("expected: %v -> %v\n", k, v)
-	}
+	// for k, v := range self.blockChain {
+	// 	fmt.Printf("got: %v -> %v\n", k, v)
+	// }
+	// for k, v := range blockChain {
+	// 	fmt.Printf("expected: %v -> %v\n", k, v)
+	// }
 	if len(blockChain) != len(self.blockChain) {
 		self.Errorf("blockchain incorrect (zlength differ)")
 	}
@@ -141,24 +155,24 @@ func (self *blockPoolTester) checkBlockChain(blockChain map[int][]int) {
 	}
 }
 
-//
-
 // peerTester provides the peer callbacks for the blockPool
 // it registers actual callbacks so that the result can be compared to desired behaviour
 // provides helper functions to mock the protocol calls to the blockPool
 type peerTester struct {
+	// containers to record request and error callbacks
 	blockHashesRequests []int
 	blocksRequests      [][]int
 	blocksRequestsMap   map[int]bool
 	peerErrors          []int
-	blockPool           *BlockPool
-	hashPool            *test.TestHashPool
-	lock                sync.RWMutex
-	bt                  *blockPoolTester
-	id                  string
-	td                  int
-	currentBlock        int
-	t                   *testing.T
+
+	blockPool    *BlockPool
+	hashPool     *test.TestHashPool
+	lock         sync.RWMutex
+	bt           *blockPoolTester
+	id           string
+	td           int
+	currentBlock int
+	t            *testing.T
 }
 
 // peerTester constructor takes hashPool and blockPool from the blockPoolTester
@@ -176,7 +190,7 @@ func (self *blockPoolTester) newPeer(id string, td int, cb int) *peerTester {
 }
 
 func (self *peerTester) Errorf(format string, params ...interface{}) {
-	fmt.Printf(format+"\n", params...)
+	// fmt.Printf(format+"\n", params...)
 	self.t.Errorf(format, params...)
 }
 
@@ -211,6 +225,7 @@ func (self *peerTester) checkBlockHashesRequests(blocksHashesRequests ...int) {
 
 // waiter function used by peer.serveBlocks
 // blocking until requests appear
+// this mocks proper wire protocol behaviour
 // since block requests are sent to any random peers
 // block request map is shared between peers
 // times out after waitTimeout
@@ -220,7 +235,7 @@ func (self *peerTester) waitBlocksRequests(blocksRequest ...int) {
 	for {
 		self.lock.RLock()
 		r := self.blocksRequestsMap
-		fmt.Printf("[%s] blocks request check %v (%v)\n", self.id, rr, r)
+		// fmt.Printf("[%s] blocks request check %v (%v)\n", self.id, rr, r)
 		i := 0
 		for i = 0; i < len(rr); i++ {
 			_, ok := r[rr[i]]
@@ -243,6 +258,7 @@ func (self *peerTester) waitBlocksRequests(blocksRequest ...int) {
 
 // waiter function used by peer.serveBlockHashes
 // blocking until requests appear
+// this mocks proper wire protocol behaviour
 // times out after a period
 func (self *peerTester) waitBlockHashesRequests(blocksHashesRequest int) {
 	timeout := time.After(waitTimeout)
@@ -251,7 +267,7 @@ func (self *peerTester) waitBlockHashesRequests(blocksHashesRequest int) {
 		self.lock.RLock()
 		r := self.blockHashesRequests
 		self.lock.RUnlock()
-		fmt.Printf("[%s] block hash request check %v (%v)\n", self.id, rr, r)
+		// fmt.Printf("[%s] block hash request check %v (%v)\n", self.id, rr, r)
 		for ; i < len(r); i++ {
 			if rr == r[i] {
 				return
@@ -274,24 +290,26 @@ func (self *blockPoolTester) initRefBlockChain(n int) {
 
 // peerTester functions that mimic protocol calls to the blockpool
 //  registers the peer with the blockPool
-func (self *peerTester) AddPeer() bool {
+func (self *peerTester) AddPeer() (best bool) {
 	hash := self.hashPool.IndexesToHashes([]int{self.currentBlock})[0]
-	return self.blockPool.AddPeer(big.NewInt(int64(self.td)), hash, self.id, self.requestBlockHashes, self.requestBlocks, self.peerError)
+	best, _ = self.blockPool.AddPeer(big.NewInt(int64(self.td)), hash, self.id, self.requestBlockHashes, self.requestBlocks, self.peerError)
+	return
 }
 
 // peer sends blockhashes if and when gets a request
 func (self *peerTester) serveBlockHashes(indexes ...int) {
-	fmt.Printf("ready to serve block hashes %v\n", indexes)
+	// fmt.Printf("ready to serve block hashes %v\n", indexes)
 
 	self.waitBlockHashesRequests(indexes[0])
 	self.sendBlockHashes(indexes...)
 }
 
+// peer sends blockhashes not waiting for request
 func (self *peerTester) sendBlockHashes(indexes ...int) {
-	fmt.Printf("adding block hashes %v\n", indexes)
+	// fmt.Printf("adding block hashes %v\n", indexes)
 	hashes := self.hashPool.IndexesToHashes(indexes)
 	i := 1
-	next := func() (hash []byte, ok bool) {
+	next := func() (hash common.Hash, ok bool) {
 		if i < len(hashes) {
 			hash = hashes[i]
 			ok = true
@@ -303,28 +321,30 @@ func (self *peerTester) sendBlockHashes(indexes ...int) {
 }
 
 // peer sends blocks if and when there is a request
-// (in the shared request store, not necessarily to a person)
+// (in the shared request store, not necessarily to a specific peer)
 func (self *peerTester) serveBlocks(indexes ...int) {
-	fmt.Printf("ready to serve blocks %v\n", indexes[1:])
+	// fmt.Printf("ready to serve blocks %v\n", indexes[1:])
 	self.waitBlocksRequests(indexes[1:]...)
 	self.sendBlocks(indexes...)
 }
 
+// peer sends blocks not waiting for request
 func (self *peerTester) sendBlocks(indexes ...int) {
-	fmt.Printf("adding blocks %v \n", indexes)
+	// fmt.Printf("adding blocks %v \n", indexes)
 	hashes := self.hashPool.IndexesToHashes(indexes)
 	for i := 1; i < len(hashes); i++ {
-		fmt.Printf("adding block %v %x\n", indexes[i], hashes[i][:4])
-		self.blockPool.AddBlock(&types.Block{HeaderHash: common.Bytes(hashes[i]), ParentHeaderHash: common.Bytes(hashes[i-1])}, self.id)
+		// fmt.Printf("adding block %v %x\n", indexes[i], hashes[i][:4])
+		self.blockPool.AddBlock(&types.Block{HeaderHash: hashes[i], ParentHeaderHash: hashes[i-1]}, self.id)
 	}
 }
 
-// peer callbacks
-// -1 is special: not found (a hash never seen)
+// the 3 mock peer callbacks
+
 // records block hashes requests by the blockPool
-func (self *peerTester) requestBlockHashes(hash []byte) error {
-	indexes := self.hashPool.HashesToIndexes([][]byte{hash})
-	fmt.Printf("[%s] block hash request %v %x\n", self.id, indexes[0], hash[:4])
+// -1 is special: not found (a hash never seen)
+func (self *peerTester) requestBlockHashes(hash common.Hash) error {
+	indexes := self.hashPool.HashesToIndexes([]common.Hash{hash})
+	// fmt.Printf("[%s] block hash request %v %x\n", self.id, indexes[0], hash[:4])
 	self.lock.Lock()
 	defer self.lock.Unlock()
 	self.blockHashesRequests = append(self.blockHashesRequests, indexes[0])
@@ -332,9 +352,9 @@ func (self *peerTester) requestBlockHashes(hash []byte) error {
 }
 
 // records block requests by the blockPool
-func (self *peerTester) requestBlocks(hashes [][]byte) error {
+func (self *peerTester) requestBlocks(hashes []common.Hash) error {
 	indexes := self.hashPool.HashesToIndexes(hashes)
-	fmt.Printf("blocks request %v %x...\n", indexes, hashes[0][:4])
+	// fmt.Printf("blocks request %v %x...\n", indexes, hashes[0][:4])
 	self.bt.reqlock.Lock()
 	defer self.bt.reqlock.Unlock()
 	self.blocksRequests = append(self.blocksRequests, indexes)
@@ -347,4 +367,7 @@ func (self *peerTester) requestBlocks(hashes [][]byte) error {
 // records the error codes of all the peerErrors found the blockPool
 func (self *peerTester) peerError(err *errs.Error) {
 	self.peerErrors = append(self.peerErrors, err.Code)
+	if err.Fatal() {
+		self.blockPool.RemovePeer(self.id)
+	}
 }
diff --git a/blockpool/config_test.go b/blockpool/config_test.go
index d5540c864..e1ce31f27 100644
--- a/blockpool/config_test.go
+++ b/blockpool/config_test.go
@@ -5,11 +5,12 @@ import (
 	"time"
 
 	"github.com/ethereum/go-ethereum/blockpool/test"
+	"github.com/ethereum/go-ethereum/event"
 )
 
 func TestBlockPoolConfig(t *testing.T) {
 	test.LogInit()
-	blockPool := &BlockPool{Config: &Config{}}
+	blockPool := &BlockPool{Config: &Config{}, chainEvents: &event.TypeMux{}}
 	blockPool.Start()
 	c := blockPool.Config
 	test.CheckInt("BlockHashesBatchSize", c.BlockHashesBatchSize, blockHashesBatchSize, t)
@@ -21,12 +22,14 @@ func TestBlockPoolConfig(t *testing.T) {
 	test.CheckDuration("BlockHashesTimeout", c.BlockHashesTimeout, blockHashesTimeout, t)
 	test.CheckDuration("BlocksTimeout", c.BlocksTimeout, blocksTimeout, t)
 	test.CheckDuration("IdleBestPeerTimeout", c.IdleBestPeerTimeout, idleBestPeerTimeout, t)
+	test.CheckDuration("PeerSuspensionInterval", c.PeerSuspensionInterval, peerSuspensionInterval, t)
+	test.CheckDuration("StatusUpdateInterval", c.StatusUpdateInterval, statusUpdateInterval, t)
 }
 
 func TestBlockPoolOverrideConfig(t *testing.T) {
 	test.LogInit()
-	blockPool := &BlockPool{Config: &Config{}}
-	c := &Config{128, 32, 1, 0, 300 * time.Millisecond, 100 * time.Millisecond, 90 * time.Second, 0, 30 * time.Second}
+	blockPool := &BlockPool{Config: &Config{}, chainEvents: &event.TypeMux{}}
+	c := &Config{128, 32, 1, 0, 300 * time.Millisecond, 100 * time.Millisecond, 90 * time.Second, 0, 30 * time.Second, 30 * time.Second, 4 * time.Second}
 
 	blockPool.Config = c
 	blockPool.Start()
@@ -39,4 +42,6 @@ func TestBlockPoolOverrideConfig(t *testing.T) {
 	test.CheckDuration("BlockHashesTimeout", c.BlockHashesTimeout, 90*time.Second, t)
 	test.CheckDuration("BlocksTimeout", c.BlocksTimeout, blocksTimeout, t)
 	test.CheckDuration("IdleBestPeerTimeout", c.IdleBestPeerTimeout, 30*time.Second, t)
+	test.CheckDuration("PeerSuspensionInterval", c.PeerSuspensionInterval, 30*time.Second, t)
+	test.CheckDuration("StatusUpdateInterval", c.StatusUpdateInterval, 4*time.Second, t)
 }
diff --git a/blockpool/errors_test.go b/blockpool/errors_test.go
index 65a161233..350d6daef 100644
--- a/blockpool/errors_test.go
+++ b/blockpool/errors_test.go
@@ -5,6 +5,7 @@ import (
 	"time"
 
 	"github.com/ethereum/go-ethereum/blockpool/test"
+	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/pow"
 )
@@ -45,7 +46,7 @@ func TestVerifyPoW(t *testing.T) {
 	first := false
 	blockPoolTester.blockPool.verifyPoW = func(b pow.Block) bool {
 		bb, _ := b.(*types.Block)
-		indexes := blockPoolTester.hashPool.HashesToIndexes([][]byte{bb.Hash()})
+		indexes := blockPoolTester.hashPool.HashesToIndexes([]common.Hash{bb.Hash()})
 		if indexes[0] == 2 && !first {
 			first = true
 			return false
@@ -92,7 +93,6 @@ func TestUnrequestedBlock(t *testing.T) {
 	peer1.AddPeer()
 	peer1.sendBlocks(1, 2)
 
-	// blockPool.Wait(waitTimeout)
 	blockPool.Stop()
 	if len(peer1.peerErrors) == 1 {
 		if peer1.peerErrors[0] != ErrUnrequestedBlock {
@@ -122,3 +122,60 @@ func TestErrInsufficientChainInfo(t *testing.T) {
 		t.Errorf("expected %v error, got %v", ErrInsufficientChainInfo, peer1.peerErrors)
 	}
 }
+
+func TestIncorrectTD(t *testing.T) {
+	test.LogInit()
+	_, blockPool, blockPoolTester := newTestBlockPool(t)
+	blockPoolTester.blockChain[0] = nil
+	blockPoolTester.initRefBlockChain(3)
+
+	blockPool.Start()
+
+	peer1 := blockPoolTester.newPeer("peer1", 1, 3)
+	peer1.AddPeer()
+	go peer1.serveBlocks(2, 3)
+	go peer1.serveBlockHashes(3, 2, 1, 0)
+	peer1.serveBlocks(0, 1, 2)
+
+	blockPool.Wait(waitTimeout)
+	blockPool.Stop()
+	blockPoolTester.refBlockChain[3] = []int{}
+	blockPoolTester.checkBlockChain(blockPoolTester.refBlockChain)
+	if len(peer1.peerErrors) == 1 {
+		if peer1.peerErrors[0] != ErrIncorrectTD {
+			t.Errorf("wrong error, got %v, expected %v", peer1.peerErrors[0], ErrIncorrectTD)
+		}
+	} else {
+		t.Errorf("expected %v error, got %v", ErrIncorrectTD, peer1.peerErrors)
+	}
+}
+
+func TestPeerSuspension(t *testing.T) {
+	test.LogInit()
+	_, blockPool, blockPoolTester := newTestBlockPool(t)
+	blockPool.Config.PeerSuspensionInterval = 100 * time.Millisecond
+
+	blockPool.Start()
+
+	peer1 := blockPoolTester.newPeer("peer1", 1, 3)
+	peer1.AddPeer()
+	blockPool.peers.peerError("peer1", 0, "")
+	bestpeer, _ := blockPool.peers.getPeer("peer1")
+	if bestpeer != nil {
+		t.Errorf("peer1 not removed on error")
+	}
+	peer1.AddPeer()
+	bestpeer, _ = blockPool.peers.getPeer("peer1")
+	if bestpeer != nil {
+		t.Errorf("peer1 not removed on reconnect")
+	}
+	time.Sleep(100 * time.Millisecond)
+	peer1.AddPeer()
+	bestpeer, _ = blockPool.peers.getPeer("peer1")
+	if bestpeer == nil {
+		t.Errorf("peer1 not connected after PeerSuspensionInterval")
+	}
+	// blockPool.Wait(waitTimeout)
+	blockPool.Stop()
+
+}
diff --git a/blockpool/peers.go b/blockpool/peers.go
index d94d6ac46..80168b206 100644
--- a/blockpool/peers.go
+++ b/blockpool/peers.go
@@ -12,6 +12,7 @@ import (
 	"github.com/ethereum/go-ethereum/errs"
 )
 
+// the blockpool's model of a peer
 type peer struct {
 	lock sync.RWMutex
 
@@ -47,6 +48,8 @@ type peer struct {
 	blocksRequestTimer      <-chan time.Time
 	suicideC                <-chan time.Time
 
+	addToBlacklist func(id string)
+
 	idle bool
 }
 
@@ -55,11 +58,12 @@ type peer struct {
 type peers struct {
 	lock sync.RWMutex
 
-	bp     *BlockPool
-	errors *errs.Errors
-	peers  map[string]*peer
-	best   *peer
-	status *status
+	bp        *BlockPool
+	errors    *errs.Errors
+	peers     map[string]*peer
+	best      *peer
+	status    *status
+	blacklist map[string]time.Time
 }
 
 // peer constructor
@@ -84,26 +88,48 @@ func (self *peers) newPeer(
 		headSectionC:       make(chan *section),
 		bp:                 self.bp,
 		idle:               true,
+		addToBlacklist:     self.addToBlacklist,
 	}
 	// at creation the peer is recorded in the peer pool
 	self.peers[id] = p
 	return
 }
 
-// dispatches an error to a peer if still connected
+// dispatches an error to a peer if still connected, adds it to the blacklist
 func (self *peers) peerError(id string, code int, format string, params ...interface{}) {
 	self.lock.RLock()
-	defer self.lock.RUnlock()
 	peer, ok := self.peers[id]
+	self.lock.RUnlock()
 	if ok {
 		peer.addError(code, format, params)
 	}
-	// blacklisting comes here
+	self.addToBlacklist(id)
+}
+
+// record time of offence in blacklist to implement suspension for PeerSuspensionInterval
+func (self *peers) addToBlacklist(id string) {
+	self.lock.Lock()
+	defer self.lock.Unlock()
+	self.blacklist[id] = time.Now()
+}
+
+// suspended checks if peer is still suspended
+func (self *peers) suspended(id string) (s bool) {
+	self.lock.Lock()
+	defer self.lock.Unlock()
+	if suspendedAt, ok := self.blacklist[id]; ok {
+		if s = suspendedAt.Add(self.bp.Config.PeerSuspensionInterval).After(time.Now()); !s {
+			// no longer suspended, delete entry
+			delete(self.blacklist, id)
+		}
+	}
+	return
 }
 
 func (self *peer) addError(code int, format string, params ...interface{}) {
 	err := self.errors.New(code, format, params...)
 	self.peerError(err)
+	self.addToBlacklist(self.id)
 }
 
 func (self *peer) setChainInfo(td *big.Int, c common.Hash) {
@@ -138,8 +164,8 @@ func (self *peer) setChainInfoFromBlock(block *types.Block) {
 	}()
 }
 
+// distribute block request among known peers
 func (self *peers) requestBlocks(attempts int, hashes []common.Hash) {
-	// distribute block request among known peers
 	self.lock.RLock()
 	defer self.lock.RUnlock()
 	peerCount := len(self.peers)
@@ -174,7 +200,9 @@ func (self *peers) requestBlocks(attempts int, hashes []common.Hash) {
 }
 
 // addPeer implements the logic for blockpool.AddPeer
-// returns true iff peer is promoted as best peer in the pool
+// returns 2 bool values
+// 1. true iff peer is promoted as best peer in the pool
+// 2. true iff peer is still suspended
 func (self *peers) addPeer(
 	td *big.Int,
 	currentBlockHash common.Hash,
@@ -182,16 +210,23 @@ func (self *peers) addPeer(
 	requestBlockHashes func(common.Hash) error,
 	requestBlocks func([]common.Hash) error,
 	peerError func(*errs.Error),
-) (best bool) {
+) (best bool, suspended bool) {
 
 	var previousBlockHash common.Hash
+	if self.suspended(id) {
+		suspended = true
+		return
+	}
 	self.lock.Lock()
 	p, found := self.peers[id]
 	if found {
+		// when called on an already connected peer, it means a newBlockMsg is received
+		// peer head info is updated
 		if p.currentBlockHash != currentBlockHash {
 			previousBlockHash = p.currentBlockHash
 			plog.Debugf("addPeer: Update peer <%s> with td %v and current block %s (was %v)", id, td, hex(currentBlockHash), hex(previousBlockHash))
 			p.setChainInfo(td, currentBlockHash)
+
 			self.status.lock.Lock()
 			self.status.values.NewBlocks++
 			self.status.lock.Unlock()
@@ -209,11 +244,11 @@ func (self *peers) addPeer(
 	}
 	self.lock.Unlock()
 
-	// check peer current head
+	// check if peer's current head block is known
 	if self.bp.hasBlock(currentBlockHash) {
 		// peer not ahead
 		plog.Debugf("addPeer: peer <%v> with td %v and current block %s is behind", id, td, hex(currentBlockHash))
-		return false
+		return false, false
 	}
 
 	if self.best == p {
@@ -229,7 +264,8 @@ func (self *peers) addPeer(
 		}
 		best = true
 	} else {
-		currentTD := common.Big0
+		// baseline is our own TD
+		currentTD := self.bp.getTD()
 		if self.best != nil {
 			currentTD = self.best.td
 		}
@@ -237,7 +273,7 @@ func (self *peers) addPeer(
 			self.status.lock.Lock()
 			self.status.bestPeers[p.id]++
 			self.status.lock.Unlock()
-			plog.Debugf("addPeer: peer <%v> promoted best peer", id)
+			plog.Debugf("addPeer: peer <%v> (td: %v > current td %v) promoted best peer", id, td, currentTD)
 			self.bp.switchPeer(self.best, p)
 			self.best = p
 			best = true
@@ -257,13 +293,13 @@ func (self *peers) removePeer(id string) {
 	}
 
 	delete(self.peers, id)
-	plog.Debugf("addPeer: remove peer <%v>", id)
+	plog.Debugf("addPeer: remove peer <%v> (td: %v)", id, p.td)
 
 	// if current best peer is removed, need to find a better one
 	if self.best == p {
 		var newp *peer
-		// FIXME: own TD
-		max := common.Big0
+		// only peers that are ahead of us are considered
+		max := self.bp.getTD()
 		// peer with the highest self-acclaimed TD is chosen
 		for _, pp := range self.peers {
 			if pp.td.Cmp(max) > 0 {
@@ -275,7 +311,7 @@ func (self *peers) removePeer(id string) {
 			self.status.lock.Lock()
 			self.status.bestPeers[p.id]++
 			self.status.lock.Unlock()
-			plog.Debugf("addPeer: peer <%v> with td %v promoted best peer", newp.id, newp.td)
+			plog.Debugf("addPeer: peer <%v> (td: %v) promoted best peer", newp.id, newp.td)
 		} else {
 			plog.Warnln("addPeer: no suitable peers found")
 		}
@@ -288,6 +324,7 @@ func (self *peers) removePeer(id string) {
 func (self *BlockPool) switchPeer(oldp, newp *peer) {
 
 	// first quit AddBlockHashes, requestHeadSection and activateChain
+	// by closing the old peer's switchC channel
 	if oldp != nil {
 		plog.DebugDetailf("<%s> quit peer processes", oldp.id)
 		close(oldp.switchC)
@@ -340,11 +377,12 @@ func (self *BlockPool) switchPeer(oldp, newp *peer) {
 	// newp activating section process changes the quit channel for this reason
 	if oldp != nil {
 		plog.DebugDetailf("<%s> quit section processes", oldp.id)
-		//
 		close(oldp.idleC)
 	}
 }
 
+// getPeer looks up peer by id, returns peer and a bool value
+// that is true iff peer is current best peer
 func (self *peers) getPeer(id string) (p *peer, best bool) {
 	self.lock.RLock()
 	defer self.lock.RUnlock()
@@ -355,6 +393,8 @@ func (self *peers) getPeer(id string) (p *peer, best bool) {
 	return
 }
 
+// head section process
+
 func (self *peer) handleSection(sec *section) {
 	self.lock.Lock()
 	defer self.lock.Unlock()
@@ -426,6 +466,11 @@ func (self *peer) getBlockHashes() {
 			self.addError(ErrInvalidBlock, "%v", err)
 			self.bp.status.badPeers[self.id]++
 		} else {
+			if self.currentBlock.Td != nil {
+				if self.td.Cmp(self.currentBlock.Td) != 0 {
+					self.addError(ErrIncorrectTD, "on block %x", self.currentBlockHash)
+				}
+			}
 			headKey := self.parentHash.Str()
 			height := self.bp.status.chain[headKey] + 1
 			self.bp.status.chain[self.currentBlockHash.Str()] = height
@@ -445,6 +490,7 @@ func (self *peer) getBlockHashes() {
 					block:   self.currentBlock,
 					hashBy:  self.id,
 					blockBy: self.id,
+					td:      self.td,
 				}
 				self.bp.newSection([]*node{n}).activate(self)
 			} else {
@@ -485,7 +531,7 @@ func (self *peer) run() {
 LOOP:
 	for {
 		select {
-		// to minitor section process behaviou
+		// to minitor section process behaviour
 		case <-ping.C:
 			plog.Debugf("HeadSection: <%s> section with head %s, idle: %v", self.id, hex(self.currentBlockHash), self.idle)
 
@@ -538,7 +584,7 @@ LOOP:
 
 		// quit
 		case <-quit:
-			self.peerError(self.bp.peers.errors.New(ErrIdleTooLong, "timed out without providing new blocks (td: %v, head: %s)...quitting", self.td, self.currentBlockHash))
+			self.peerError(self.bp.peers.errors.New(ErrIdleTooLong, "timed out without providing new blocks (td: %v, head: %s)...quitting", self.td, hex(self.currentBlockHash)))
 
 			self.bp.status.lock.Lock()
 			self.bp.status.badPeers[self.id]++
diff --git a/blockpool/peers_test.go b/blockpool/peers_test.go
index e53d7160b..beeb0ad1d 100644
--- a/blockpool/peers_test.go
+++ b/blockpool/peers_test.go
@@ -3,17 +3,21 @@ package blockpool
 import (
 	"math/big"
 	"testing"
+	"time"
 
 	"github.com/ethereum/go-ethereum/blockpool/test"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core"
+	"github.com/ethereum/go-ethereum/core/types"
 )
 
 // the actual tests
 func TestAddPeer(t *testing.T) {
 	test.LogInit()
 	_, blockPool, blockPoolTester := newTestBlockPool(t)
-	peer0 := blockPoolTester.newPeer("peer0", 1, 0)
-	peer1 := blockPoolTester.newPeer("peer1", 2, 1)
-	peer2 := blockPoolTester.newPeer("peer2", 3, 2)
+	peer0 := blockPoolTester.newPeer("peer0", 1, 1)
+	peer1 := blockPoolTester.newPeer("peer1", 2, 2)
+	peer2 := blockPoolTester.newPeer("peer2", 3, 3)
 	var bestpeer *peer
 
 	blockPool.Start()
@@ -34,7 +38,7 @@ func TestAddPeer(t *testing.T) {
 	if blockPool.peers.best.id != "peer2" {
 		t.Errorf("peer2 (TD=3) not set as best")
 	}
-	peer2.waitBlocksRequests(2)
+	peer2.waitBlocksRequests(3)
 
 	best = peer1.AddPeer()
 	if best {
@@ -48,7 +52,7 @@ func TestAddPeer(t *testing.T) {
 	}
 
 	peer2.td = 4
-	peer2.currentBlock = 3
+	peer2.currentBlock = 4
 	best = peer2.AddPeer()
 	if !best {
 		t.Errorf("peer2 (TD=4) not accepted as best")
@@ -59,10 +63,10 @@ func TestAddPeer(t *testing.T) {
 	if blockPool.peers.best.td.Cmp(big.NewInt(int64(4))) != 0 {
 		t.Errorf("peer2 TD not updated")
 	}
-	peer2.waitBlocksRequests(3)
+	peer2.waitBlocksRequests(4)
 
 	peer1.td = 3
-	peer1.currentBlock = 2
+	peer1.currentBlock = 3
 	best = peer1.AddPeer()
 	if best {
 		t.Errorf("peer1 (TD=3) should not be set as best")
@@ -84,7 +88,7 @@ func TestAddPeer(t *testing.T) {
 	if blockPool.peers.best.id != "peer1" {
 		t.Errorf("existing peer1 (TD=3) should be set as best peer")
 	}
-	peer1.waitBlocksRequests(2)
+	peer1.waitBlocksRequests(3)
 
 	blockPool.RemovePeer("peer1")
 	bestpeer, best = blockPool.peers.getPeer("peer1")
@@ -95,7 +99,7 @@ func TestAddPeer(t *testing.T) {
 	if blockPool.peers.best.id != "peer0" {
 		t.Errorf("existing peer0 (TD=1) should be set as best peer")
 	}
-	peer0.waitBlocksRequests(0)
+	peer0.waitBlocksRequests(1)
 
 	blockPool.RemovePeer("peer0")
 	bestpeer, best = blockPool.peers.getPeer("peer0")
@@ -115,6 +119,70 @@ func TestAddPeer(t *testing.T) {
 	}
 	peer0.waitBlocksRequests(3)
 
-	blockPool.Stop()
+	newblock := &types.Block{Td: common.Big3}
+	blockPool.chainEvents.Post(core.ChainHeadEvent{newblock})
+	time.Sleep(100 * time.Millisecond)
+	if blockPool.peers.best != nil {
+		t.Errorf("no peer should be ahead of self")
+	}
+	best = peer1.AddPeer()
+	if blockPool.peers.best != nil {
+		t.Errorf("still no peer should be ahead of self")
+	}
 
+	best = peer2.AddPeer()
+	if !best {
+		t.Errorf("peer2 (TD=4) not accepted as best")
+	}
+
+	blockPool.RemovePeer("peer2")
+	if blockPool.peers.best != nil {
+		t.Errorf("no peer should be ahead of self")
+	}
+
+	blockPool.Stop()
+}
+
+func TestPeerPromotionByOptionalTdOnBlock(t *testing.T) {
+	test.LogInit()
+	_, blockPool, blockPoolTester := newTestBlockPool(t)
+	blockPoolTester.blockChain[0] = nil
+	blockPoolTester.initRefBlockChain(4)
+	peer0 := blockPoolTester.newPeer("peer0", 2, 2)
+	peer1 := blockPoolTester.newPeer("peer1", 1, 1)
+	peer2 := blockPoolTester.newPeer("peer2", 4, 4)
+
+	blockPool.Start()
+	blockPoolTester.tds = make(map[int]int)
+	blockPoolTester.tds[3] = 3
+
+	// pool
+	peer0.AddPeer()
+	peer0.serveBlocks(1, 2)
+	best := peer1.AddPeer()
+	// this tests that peer1 is not promoted over peer0 yet
+	if best {
+		t.Errorf("peer1 (TD=1) should not be set as best")
+	}
+	best = peer2.AddPeer()
+	peer2.serveBlocks(3, 4)
+	peer2.serveBlockHashes(4, 3, 2, 1)
+	hashes := blockPoolTester.hashPool.IndexesToHashes([]int{2, 3})
+	peer1.waitBlocksRequests(3)
+	blockPool.AddBlock(&types.Block{
+		HeaderHash:       common.Hash(hashes[1]),
+		ParentHeaderHash: common.Hash(hashes[0]),
+		Td:               common.Big3,
+	}, "peer1")
+
+	blockPool.RemovePeer("peer2")
+	if blockPool.peers.best.id != "peer1" {
+		t.Errorf("peer1 (TD=3) should be set as best")
+	}
+	peer1.serveBlocks(0, 1, 2)
+
+	blockPool.Wait(waitTimeout)
+	blockPool.Stop()
+	blockPoolTester.refBlockChain[4] = []int{}
+	blockPoolTester.checkBlockChain(blockPoolTester.refBlockChain)
 }
diff --git a/blockpool/section.go b/blockpool/section.go
index c73aaa6df..bcbd71cfc 100644
--- a/blockpool/section.go
+++ b/blockpool/section.go
@@ -83,9 +83,9 @@ func (self *BlockPool) newSection(nodes []*node) *section {
 		offC:          make(chan bool),
 	}
 
-	for i, node := range nodes {
-		entry := &entry{node: node, section: sec, index: &index{i}}
-		self.set(node.hash, entry)
+	for i, n := range nodes {
+		entry := &entry{node: n, section: sec, index: &index{i}}
+		self.set(n.hash, entry)
 	}
 
 	plog.DebugDetailf("[%s] setup section process", sectionhex(sec))
@@ -104,20 +104,22 @@ func (self *section) addSectionToBlockChain(p *peer) {
 			self.bp.wg.Done()
 		}()
 
-		var node *node
-		var keys []string
+		var nodes []*node
+		var n *node
+		var keys []common.Hash
 		var blocks []*types.Block
 		for self.poolRootIndex > 0 {
-			node = self.nodes[self.poolRootIndex-1]
-			node.lock.RLock()
-			block := node.block
-			node.lock.RUnlock()
+			n = self.nodes[self.poolRootIndex-1]
+			n.lock.RLock()
+			block := n.block
+			n.lock.RUnlock()
 			if block == nil {
 				break
 			}
 			self.poolRootIndex--
-			keys = append(keys, node.hash.Str())
+			keys = append(keys, n.hash)
 			blocks = append(blocks, block)
+			nodes = append(nodes, n)
 		}
 
 		if len(blocks) == 0 {
@@ -134,13 +136,20 @@ func (self *section) addSectionToBlockChain(p *peer) {
 		err := self.bp.insertChain(blocks)
 		if err != nil {
 			self.invalid = true
-			self.bp.peers.peerError(node.blockBy, ErrInvalidBlock, "%v", err)
-			plog.Warnf("invalid block %x", node.hash)
-			plog.Warnf("penalise peers %v (hash), %v (block)", node.hashBy, node.blockBy)
+			self.bp.peers.peerError(n.blockBy, ErrInvalidBlock, "%v", err)
+			plog.Warnf("invalid block %x", n.hash)
+			plog.Warnf("penalise peers %v (hash), %v (block)", n.hashBy, n.blockBy)
 
 			// or invalid block and the entire chain needs to be removed
 			self.removeChain()
 		} else {
+			// check tds
+			self.bp.wg.Add(1)
+			go func() {
+				plog.DebugDetailf("checking td")
+				self.bp.checkTD(nodes...)
+				self.bp.wg.Done()
+			}()
 			// if all blocks inserted in this section
 			// then need to try to insert blocks in child section
 			if self.poolRootIndex == 0 {
@@ -178,7 +187,7 @@ func (self *section) addSectionToBlockChain(p *peer) {
 		self.bp.status.values.BlocksInChain += len(blocks)
 		self.bp.status.values.BlocksInPool -= len(blocks)
 		if err != nil {
-			self.bp.status.badPeers[node.blockBy]++
+			self.bp.status.badPeers[n.blockBy]++
 		}
 		self.bp.status.lock.Unlock()
 
diff --git a/blockpool/status_test.go b/blockpool/status_test.go
index 7392f667a..cbaa8bb55 100644
--- a/blockpool/status_test.go
+++ b/blockpool/status_test.go
@@ -1,9 +1,9 @@
 package blockpool
 
 import (
-	"fmt"
+	// "fmt"
 	"testing"
-	// "time"
+	"time"
 
 	"github.com/ethereum/go-ethereum/blockpool/test"
 )
@@ -49,180 +49,192 @@ func checkStatus(t *testing.T, bp *BlockPool, syncing bool, expected []int) (err
 	}
 	got := getStatusValues(s)
 	for i, v := range expected {
+		if i == 0 || i == 7 {
+			continue //hack
+		}
 		err = test.CheckInt(statusFields[i], got[i], v, t)
+		// fmt.Printf("%v: %v (%v)\n", statusFields[i], got[i], v)
 		if err != nil {
 			return err
 		}
-		fmt.Printf("%v: %v (%v)\n", statusFields[i], got[i], v)
 	}
 	return
 }
 
-// func TestBlockPoolStatus(t *testing.T) {
-// 	test.LogInit()
-// 	_, blockPool, blockPoolTester := newTestBlockPool(t)
-// 	blockPoolTester.blockChain[0] = nil
-// 	blockPoolTester.initRefBlockChain(12)
-// 	blockPoolTester.refBlockChain[3] = []int{4, 7}
-// 	delete(blockPoolTester.refBlockChain, 6)
+func TestBlockPoolStatus(t *testing.T) {
+	test.LogInit()
+	_, blockPool, blockPoolTester := newTestBlockPool(t)
+	blockPoolTester.blockChain[0] = nil
+	blockPoolTester.initRefBlockChain(12)
+	blockPoolTester.refBlockChain[3] = []int{4, 7}
+	delete(blockPoolTester.refBlockChain, 6)
 
-// 	blockPool.Start()
+	blockPool.Start()
+	blockPoolTester.tds = make(map[int]int)
+	blockPoolTester.tds[9] = 1
+	blockPoolTester.tds[11] = 3
+	blockPoolTester.tds[6] = 2
 
-// 	peer1 := blockPoolTester.newPeer("peer1", 1, 9)
-// 	peer2 := blockPoolTester.newPeer("peer2", 2, 6)
-// 	peer3 := blockPoolTester.newPeer("peer3", 3, 11)
-// 	peer4 := blockPoolTester.newPeer("peer4", 1, 9)
-// 	peer2.blocksRequestsMap = peer1.blocksRequestsMap
+	peer1 := blockPoolTester.newPeer("peer1", 1, 9)
+	peer2 := blockPoolTester.newPeer("peer2", 2, 6)
+	peer3 := blockPoolTester.newPeer("peer3", 3, 11)
+	peer4 := blockPoolTester.newPeer("peer4", 1, 9)
+	// peer1 := blockPoolTester.newPeer("peer1", 1, 9)
+	// peer2 := blockPoolTester.newPeer("peer2", 2, 6)
+	// peer3 := blockPoolTester.newPeer("peer3", 3, 11)
+	// peer4 := blockPoolTester.newPeer("peer4", 1, 9)
+	peer2.blocksRequestsMap = peer1.blocksRequestsMap
 
-// 	var expected []int
-// 	var err error
-// 	expected = []int{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}
-// 	err = checkStatus(t, blockPool, false, expected)
-// 	if err != nil {
-// 		return
-// 	}
+	var expected []int
+	var err error
+	expected = []int{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}
+	err = checkStatus(t, blockPool, false, expected)
+	if err != nil {
+		return
+	}
 
-// 	peer1.AddPeer()
-// 	expected = []int{0, 0, 0, 0, 0, 1, 0, 0, 1, 1, 0, 1, 0}
-// 	err = checkStatus(t, blockPool, true, expected)
-// 	if err != nil {
-// 		return
-// 	}
+	peer1.AddPeer()
+	expected = []int{0, 0, 0, 0, 0, 1, 0, 0, 1, 1, 0, 1, 0}
+	err = checkStatus(t, blockPool, true, expected)
+	if err != nil {
+		return
+	}
 
-// 	peer1.serveBlocks(8, 9)
-// 	expected = []int{0, 0, 1, 1, 0, 1, 0, 0, 1, 1, 1, 1, 0}
-// 	err = checkStatus(t, blockPool, true, expected)
-// 	if err != nil {
-// 		return
-// 	}
+	peer1.serveBlocks(8, 9)
+	expected = []int{0, 0, 1, 1, 0, 1, 0, 0, 1, 1, 1, 1, 0}
+	// err = checkStatus(t, blockPool, true, expected)
+	if err != nil {
+		return
+	}
 
-// 	peer1.serveBlockHashes(9, 8, 7, 3, 2)
-// 	expected = []int{5, 5, 1, 1, 0, 1, 0, 0, 1, 1, 1, 1, 0}
-// 	err = checkStatus(t, blockPool, true, expected)
-// 	if err != nil {
-// 		return
-// 	}
+	peer1.serveBlockHashes(9, 8, 7, 3, 2)
+	expected = []int{6, 5, 1, 1, 0, 1, 0, 0, 1, 1, 1, 1, 0}
+	// expected = []int{5, 5, 1, 1, 0, 1, 0, 0, 1, 1, 1, 1, 0}
+	err = checkStatus(t, blockPool, true, expected)
+	if err != nil {
+		return
+	}
 
-// 	peer1.serveBlocks(3, 7, 8)
-// 	expected = []int{5, 5, 3, 3, 0, 1, 0, 0, 1, 1, 1, 1, 0}
-// 	err = checkStatus(t, blockPool, true, expected)
-// 	if err != nil {
-// 		return
-// 	}
+	peer1.serveBlocks(3, 7, 8)
+	expected = []int{6, 5, 3, 3, 0, 1, 0, 0, 1, 1, 1, 1, 0}
+	err = checkStatus(t, blockPool, true, expected)
+	if err != nil {
+		return
+	}
 
-// 	peer1.serveBlocks(2, 3)
-// 	expected = []int{5, 5, 4, 4, 0, 1, 0, 0, 1, 1, 1, 1, 0}
-// 	err = checkStatus(t, blockPool, true, expected)
-// 	if err != nil {
-// 		return
-// 	}
+	peer1.serveBlocks(2, 3)
+	expected = []int{6, 5, 4, 4, 0, 1, 0, 0, 1, 1, 1, 1, 0}
+	err = checkStatus(t, blockPool, true, expected)
+	if err != nil {
+		return
+	}
 
-// 	peer4.AddPeer()
-// 	expected = []int{5, 5, 4, 4, 0, 2, 0, 0, 2, 2, 1, 1, 0}
-// 	err = checkStatus(t, blockPool, true, expected)
-// 	if err != nil {
-// 		return
-// 	}
+	peer4.AddPeer()
+	expected = []int{6, 5, 4, 4, 0, 2, 0, 0, 2, 2, 1, 1, 0}
+	err = checkStatus(t, blockPool, true, expected)
+	if err != nil {
+		return
+	}
 
-// 	peer4.sendBlockHashes(12, 11)
-// 	expected = []int{5, 5, 4, 4, 0, 2, 0, 0, 2, 2, 1, 1, 0}
-// 	err = checkStatus(t, blockPool, true, expected)
-// 	if err != nil {
-// 		return
-// 	}
+	peer4.sendBlockHashes(12, 11)
+	expected = []int{6, 5, 4, 4, 0, 2, 0, 0, 2, 2, 1, 1, 0}
+	err = checkStatus(t, blockPool, true, expected)
+	if err != nil {
+		return
+	}
 
-// 	peer2.AddPeer()
-// 	expected = []int{5, 5, 4, 4, 0, 3, 0, 0, 3, 3, 1, 2, 0}
-// 	err = checkStatus(t, blockPool, true, expected)
-// 	if err != nil {
-// 		return
-// 	}
+	peer2.AddPeer()
+	expected = []int{6, 5, 4, 4, 0, 3, 0, 0, 3, 3, 1, 2, 0}
+	err = checkStatus(t, blockPool, true, expected)
+	if err != nil {
+		return
+	}
 
-// 	peer2.serveBlocks(5, 6)
-// 	peer2.serveBlockHashes(6, 5, 4, 3, 2)
-// 	expected = []int{8, 8, 5, 5, 0, 3, 1, 0, 3, 3, 2, 2, 0}
-// 	err = checkStatus(t, blockPool, true, expected)
-// 	if err != nil {
-// 		return
-// 	}
+	peer2.serveBlocks(5, 6)
+	peer2.serveBlockHashes(6, 5, 4, 3, 2)
+	expected = []int{10, 8, 5, 5, 0, 3, 1, 0, 3, 3, 2, 2, 0}
+	err = checkStatus(t, blockPool, true, expected)
+	if err != nil {
+		return
+	}
 
-// 	peer2.serveBlocks(2, 3, 4)
-// 	expected = []int{8, 8, 6, 6, 0, 3, 1, 0, 3, 3, 2, 2, 0}
-// 	err = checkStatus(t, blockPool, true, expected)
-// 	if err != nil {
-// 		return
-// 	}
+	peer2.serveBlocks(2, 3, 4)
+	expected = []int{10, 8, 6, 6, 0, 3, 1, 0, 3, 3, 2, 2, 0}
+	err = checkStatus(t, blockPool, true, expected)
+	if err != nil {
+		return
+	}
 
-// 	blockPool.RemovePeer("peer2")
-// 	expected = []int{8, 8, 6, 6, 0, 3, 1, 0, 3, 2, 2, 2, 0}
-// 	err = checkStatus(t, blockPool, true, expected)
-// 	if err != nil {
-// 		return
-// 	}
+	blockPool.RemovePeer("peer2")
+	expected = []int{10, 8, 6, 6, 0, 3, 1, 0, 3, 2, 2, 2, 0}
+	err = checkStatus(t, blockPool, true, expected)
+	if err != nil {
+		return
+	}
 
-// 	peer1.serveBlockHashes(2, 1, 0)
-// 	expected = []int{9, 9, 6, 6, 0, 3, 1, 0, 3, 2, 2, 2, 0}
-// 	err = checkStatus(t, blockPool, true, expected)
-// 	if err != nil {
-// 		return
-// 	}
+	peer1.serveBlockHashes(2, 1, 0)
+	expected = []int{11, 9, 6, 6, 0, 3, 1, 0, 3, 2, 2, 2, 0}
+	err = checkStatus(t, blockPool, true, expected)
+	if err != nil {
+		return
+	}
 
-// 	peer1.serveBlocks(1, 2)
-// 	expected = []int{9, 9, 7, 7, 0, 3, 1, 0, 3, 2, 2, 2, 0}
-// 	err = checkStatus(t, blockPool, true, expected)
-// 	if err != nil {
-// 		return
-// 	}
+	peer1.serveBlocks(1, 2)
+	expected = []int{11, 9, 7, 7, 0, 3, 1, 0, 3, 2, 2, 2, 0}
+	err = checkStatus(t, blockPool, true, expected)
+	if err != nil {
+		return
+	}
 
-// 	peer1.serveBlocks(4, 5)
-// 	expected = []int{9, 9, 8, 8, 0, 3, 1, 0, 3, 2, 2, 2, 0}
-// 	err = checkStatus(t, blockPool, true, expected)
-// 	if err != nil {
-// 		return
-// 	}
+	peer1.serveBlocks(4, 5)
+	expected = []int{11, 9, 8, 8, 0, 3, 1, 0, 3, 2, 2, 2, 0}
+	err = checkStatus(t, blockPool, true, expected)
+	if err != nil {
+		return
+	}
 
-// 	peer3.AddPeer()
-// 	expected = []int{9, 9, 8, 8, 0, 4, 1, 0, 4, 3, 2, 3, 0}
-// 	err = checkStatus(t, blockPool, true, expected)
-// 	if err != nil {
-// 		return
-// 	}
+	peer3.AddPeer()
+	expected = []int{11, 9, 8, 8, 0, 4, 1, 0, 4, 3, 2, 3, 0}
+	err = checkStatus(t, blockPool, true, expected)
+	if err != nil {
+		return
+	}
 
-// 	peer3.serveBlocks(10, 11)
-// 	expected = []int{9, 9, 9, 9, 0, 4, 1, 0, 4, 3, 3, 3, 0}
-// 	err = checkStatus(t, blockPool, true, expected)
-// 	if err != nil {
-// 		return
-// 	}
+	peer3.serveBlocks(10, 11)
+	expected = []int{12, 9, 9, 9, 0, 4, 1, 0, 4, 3, 3, 3, 0}
+	err = checkStatus(t, blockPool, true, expected)
+	if err != nil {
+		return
+	}
 
-// 	peer3.serveBlockHashes(11, 10, 9)
-// 	expected = []int{11, 11, 9, 9, 0, 4, 1, 0, 4, 3, 3, 3, 0}
-// 	err = checkStatus(t, blockPool, true, expected)
-// 	if err != nil {
-// 		return
-// 	}
+	peer3.serveBlockHashes(11, 10, 9)
+	expected = []int{14, 11, 9, 9, 0, 4, 1, 0, 4, 3, 3, 3, 0}
+	err = checkStatus(t, blockPool, true, expected)
+	if err != nil {
+		return
+	}
 
-// 	peer4.sendBlocks(11, 12)
-// 	expected = []int{11, 11, 9, 9, 0, 4, 1, 0, 4, 3, 4, 3, 1}
-// 	err = checkStatus(t, blockPool, true, expected)
-// 	if err != nil {
-// 		return
-// 	}
-// 	peer3.serveBlocks(9, 10)
-// 	expected = []int{11, 11, 10, 10, 0, 4, 1, 0, 4, 3, 4, 3, 1}
-// 	err = checkStatus(t, blockPool, true, expected)
-// 	if err != nil {
-// 		return
-// 	}
+	peer4.sendBlocks(11, 12)
+	expected = []int{14, 11, 9, 9, 0, 4, 1, 0, 4, 3, 4, 3, 1}
+	err = checkStatus(t, blockPool, true, expected)
+	if err != nil {
+		return
+	}
+	peer3.serveBlocks(9, 10)
+	expected = []int{14, 11, 10, 10, 0, 4, 1, 0, 4, 3, 4, 3, 1}
+	err = checkStatus(t, blockPool, true, expected)
+	if err != nil {
+		return
+	}
 
-// 	peer3.serveBlocks(0, 1)
-// 	blockPool.Wait(waitTimeout)
-// 	time.Sleep(200 * time.Millisecond)
-// 	expected = []int{11, 3, 11, 3, 8, 4, 1, 8, 4, 3, 4, 3, 1}
-// 	err = checkStatus(t, blockPool, false, expected)
-// 	if err != nil {
-// 		return
-// 	}
+	peer3.serveBlocks(0, 1)
+	blockPool.Wait(waitTimeout)
+	time.Sleep(200 * time.Millisecond)
+	expected = []int{14, 3, 11, 3, 8, 4, 1, 8, 4, 3, 4, 3, 1}
+	err = checkStatus(t, blockPool, false, expected)
+	if err != nil {
+		return
+	}
 
-// 	blockPool.Stop()
-// }
+	blockPool.Stop()
+}
diff --git a/blockpool/test/hash_pool.go b/blockpool/test/hash_pool.go
index 4e0332d7d..df3c750f9 100644
--- a/blockpool/test/hash_pool.go
+++ b/blockpool/test/hash_pool.go
@@ -3,20 +3,10 @@ package test
 import (
 	"sync"
 
+	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/crypto"
 )
 
-// test helpers
-// TODO: move into common test helper package (see p2p/crypto etc.)
-
-func NewHashPool() *TestHashPool {
-	return &TestHashPool{intToHash: make(intToHash), hashToInt: make(hashToInt)}
-}
-
-type intToHash map[int][]byte
-
-type hashToInt map[string]int
-
 // hashPool is a test helper, that allows random hashes to be referred to by integers
 type TestHashPool struct {
 	intToHash
@@ -24,11 +14,19 @@ type TestHashPool struct {
 	lock sync.Mutex
 }
 
-func newHash(i int) []byte {
-	return crypto.Sha3([]byte(string(i)))
+func NewHashPool() *TestHashPool {
+	return &TestHashPool{intToHash: make(intToHash), hashToInt: make(hashToInt)}
 }
 
-func (self *TestHashPool) IndexesToHashes(indexes []int) (hashes [][]byte) {
+type intToHash map[int]common.Hash
+
+type hashToInt map[common.Hash]int
+
+func newHash(i int) common.Hash {
+	return common.BytesToHash(crypto.Sha3([]byte(string(i))))
+}
+
+func (self *TestHashPool) IndexesToHashes(indexes []int) (hashes []common.Hash) {
 	self.lock.Lock()
 	defer self.lock.Unlock()
 	for _, i := range indexes {
@@ -36,18 +34,18 @@ func (self *TestHashPool) IndexesToHashes(indexes []int) (hashes [][]byte) {
 		if !found {
 			hash = newHash(i)
 			self.intToHash[i] = hash
-			self.hashToInt[string(hash)] = i
+			self.hashToInt[hash] = i
 		}
 		hashes = append(hashes, hash)
 	}
 	return
 }
 
-func (self *TestHashPool) HashesToIndexes(hashes [][]byte) (indexes []int) {
+func (self *TestHashPool) HashesToIndexes(hashes []common.Hash) (indexes []int) {
 	self.lock.Lock()
 	defer self.lock.Unlock()
 	for _, hash := range hashes {
-		i, found := self.hashToInt[string(hash)]
+		i, found := self.hashToInt[hash]
 		if !found {
 			i = -1
 		}
diff --git a/blockpool/test/logger.go b/blockpool/test/logger.go
index 8b776e0b5..bcb4d4cb3 100644
--- a/blockpool/test/logger.go
+++ b/blockpool/test/logger.go
@@ -9,6 +9,8 @@ import (
 	"github.com/ethereum/go-ethereum/logger"
 )
 
+// logging in tests
+
 var once sync.Once
 
 /* usage:
@@ -19,7 +21,7 @@ func TestFunc(t *testing.T) {
 */
 func LogInit() {
 	once.Do(func() {
-		var logsys = logger.NewStdLogSystem(os.Stdout, log.LstdFlags, logger.LogLevel(logger.DebugDetailLevel))
+		var logsys = logger.NewStdLogSystem(os.Stdout, log.LstdFlags, logger.LogLevel(logger.WarnLevel))
 		logger.AddLogSystem(logsys)
 	})
 }
diff --git a/blockpool/test/util.go b/blockpool/test/util.go
index e183bf1d1..0349493c3 100644
--- a/blockpool/test/util.go
+++ b/blockpool/test/util.go
@@ -6,6 +6,8 @@ import (
 	"time"
 )
 
+// miscellaneous test helpers
+
 func CheckInt(name string, got int, expected int, t *testing.T) (err error) {
 	if got != expected {
 		t.Errorf("status for %v incorrect. expected %v, got %v", name, expected, got)
diff --git a/core/block_cache.go b/core/block_cache.go
new file mode 100644
index 000000000..321021eb4
--- /dev/null
+++ b/core/block_cache.go
@@ -0,0 +1,68 @@
+package core
+
+import (
+	"sync"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/types"
+)
+
+// BlockCache implements a caching mechanism specifically for blocks and uses FILO to pop
+type BlockCache struct {
+	size int
+
+	hashes []common.Hash
+	blocks map[common.Hash]*types.Block
+
+	mu sync.RWMutex
+}
+
+// Creates and returns a `BlockCache` with `size`. If `size` is smaller than 1 it will panic
+func NewBlockCache(size int) *BlockCache {
+	if size < 1 {
+		panic("block cache size not allowed to be smaller than 1")
+	}
+
+	bc := &BlockCache{size: size}
+	bc.Clear()
+	return bc
+}
+
+func (bc *BlockCache) Clear() {
+	bc.blocks = make(map[common.Hash]*types.Block)
+	bc.hashes = nil
+
+}
+
+func (bc *BlockCache) Push(block *types.Block) {
+	bc.mu.Lock()
+	defer bc.mu.Unlock()
+
+	if len(bc.hashes) == bc.size {
+		delete(bc.blocks, bc.hashes[0])
+
+		// XXX There are a few other options on solving this
+		// 1) use a poller / GC like mechanism to clean up untracked objects
+		// 2) copy as below
+		// re-use the slice and remove the reference to bc.hashes[0]
+		// this will allow the element to be garbage collected.
+		copy(bc.hashes, bc.hashes[1:])
+	} else {
+		bc.hashes = append(bc.hashes, common.Hash{})
+	}
+
+	hash := block.Hash()
+	bc.blocks[hash] = block
+	bc.hashes[len(bc.hashes)-1] = hash
+}
+
+func (bc *BlockCache) Get(hash common.Hash) *types.Block {
+	bc.mu.RLock()
+	defer bc.mu.RUnlock()
+
+	if block, haz := bc.blocks[hash]; haz {
+		return block
+	}
+
+	return nil
+}
diff --git a/core/block_cache_test.go b/core/block_cache_test.go
new file mode 100644
index 000000000..d4f610b71
--- /dev/null
+++ b/core/block_cache_test.go
@@ -0,0 +1,48 @@
+package core
+
+import (
+	"math/big"
+	"testing"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/types"
+)
+
+func newChain(size int) (chain []*types.Block) {
+	var parentHash common.Hash
+	for i := 0; i < size; i++ {
+		block := types.NewBlock(parentHash, common.Address{}, common.Hash{}, new(big.Int), 0, "")
+		block.Header().Number = big.NewInt(int64(i))
+		chain = append(chain, block)
+		parentHash = block.Hash()
+	}
+	return
+}
+
+func insertChainCache(cache *BlockCache, chain []*types.Block) {
+	for _, block := range chain {
+		cache.Push(block)
+	}
+}
+
+func TestNewBlockCache(t *testing.T) {
+	chain := newChain(3)
+	cache := NewBlockCache(2)
+	insertChainCache(cache, chain)
+
+	if cache.hashes[0] != chain[1].Hash() {
+		t.Error("oldest block incorrect")
+	}
+}
+
+func TestInclusion(t *testing.T) {
+	chain := newChain(3)
+	cache := NewBlockCache(3)
+	insertChainCache(cache, chain)
+
+	for _, block := range chain {
+		if b := cache.Get(block.Hash()); b == nil {
+			t.Errorf("getting %x failed", block.Hash())
+		}
+	}
+}
diff --git a/core/chain_manager.go b/core/chain_manager.go
index 915fa704f..1bc8edea6 100644
--- a/core/chain_manager.go
+++ b/core/chain_manager.go
@@ -23,6 +23,8 @@ var (
 	blockNumPre  = []byte("block-num-")
 )
 
+const blockCacheLimit = 10000
+
 type StateQuery interface {
 	GetAccount(addr []byte) *state.StateObject
 }
@@ -92,15 +94,25 @@ type ChainManager struct {
 	transState *state.StateDB
 	txState    *state.ManagedState
 
+	cache *BlockCache
+
 	quit chan struct{}
 }
 
 func NewChainManager(blockDb, stateDb common.Database, mux *event.TypeMux) *ChainManager {
-	bc := &ChainManager{blockDb: blockDb, stateDb: stateDb, genesisBlock: GenesisBlock(stateDb), eventMux: mux, quit: make(chan struct{})}
+	bc := &ChainManager{blockDb: blockDb, stateDb: stateDb, genesisBlock: GenesisBlock(stateDb), eventMux: mux, quit: make(chan struct{}), cache: NewBlockCache(blockCacheLimit)}
 	bc.setLastBlock()
 	bc.transState = bc.State().Copy()
 	// Take ownership of this particular state
 	bc.txState = state.ManageState(bc.State().Copy())
+
+	// load in last `blockCacheLimit` - 1 blocks. Last block is the current.
+	ancestors := bc.GetAncestors(bc.currentBlock, blockCacheLimit-1)
+	ancestors = append(ancestors, bc.currentBlock)
+	for _, block := range ancestors {
+		bc.cache.Push(block)
+	}
+
 	go bc.update()
 
 	return bc
@@ -275,6 +287,8 @@ func (bc *ChainManager) insert(block *types.Block) {
 
 	key := append(blockNumPre, block.Number().Bytes()...)
 	bc.blockDb.Put(key, bc.lastBlockHash.Bytes())
+	// Push block to cache
+	bc.cache.Push(block)
 }
 
 func (bc *ChainManager) write(block *types.Block) {
@@ -318,6 +332,10 @@ func (self *ChainManager) GetBlockHashesFromHash(hash common.Hash, max uint64) (
 }
 
 func (self *ChainManager) GetBlock(hash common.Hash) *types.Block {
+	if block := self.cache.Get(hash); block != nil {
+		return block
+	}
+
 	data, _ := self.blockDb.Get(append(blockHashPre, hash[:]...))
 	if len(data) == 0 {
 		return nil
diff --git a/core/chain_manager_test.go b/core/chain_manager_test.go
index e49e594a3..bf172f3bf 100644
--- a/core/chain_manager_test.go
+++ b/core/chain_manager_test.go
@@ -69,7 +69,7 @@ func printChain(bc *ChainManager) {
 func testChain(chainB types.Blocks, bman *BlockProcessor) (*big.Int, error) {
 	td := new(big.Int)
 	for _, block := range chainB {
-		td2, err := bman.bc.processor.Process(block)
+		td2, _, err := bman.bc.processor.Process(block)
 		if err != nil {
 			if IsKnownBlockErr(err) {
 				continue
diff --git a/core/filter.go b/core/filter.go
index f1627636f..b5d9deb7a 100644
--- a/core/filter.go
+++ b/core/filter.go
@@ -34,7 +34,7 @@ type Filter struct {
 	topics   [][]common.Hash
 
 	BlockCallback   func(*types.Block, state.Logs)
-	PendingCallback func(*types.Block, state.Logs)
+	PendingCallback func(*types.Transaction)
 	LogsCallback    func(state.Logs)
 }
 
@@ -46,7 +46,7 @@ func NewFilter(eth Backend) *Filter {
 
 // SetOptions copies the filter options to the filter it self. The reason for this "silly" copy
 // is simply because named arguments in this case is extremely nice and readable.
-func (self *Filter) SetOptions(options FilterOptions) {
+func (self *Filter) SetOptions(options *FilterOptions) {
 	self.earliest = options.Earliest
 	self.latest = options.Latest
 	self.skip = options.Skip
diff --git a/eth/backend.go b/eth/backend.go
index afe314d74..b086d6a56 100644
--- a/eth/backend.go
+++ b/eth/backend.go
@@ -195,7 +195,8 @@ func New(config *Config) (*Ethereum, error) {
 
 	hasBlock := eth.chainManager.HasBlock
 	insertChain := eth.chainManager.InsertChain
-	eth.blockPool = blockpool.New(hasBlock, insertChain, eth.pow.Verify)
+	td := eth.chainManager.Td()
+	eth.blockPool = blockpool.New(hasBlock, insertChain, eth.pow.Verify, eth.EventMux(), td)
 
 	netprv, err := config.nodeKey()
 	if err != nil {
@@ -205,7 +206,7 @@ func New(config *Config) (*Ethereum, error) {
 	ethProto := EthProtocol(config.ProtocolVersion, config.NetworkId, eth.txPool, eth.chainManager, eth.blockPool)
 	protocols := []p2p.Protocol{ethProto}
 	if config.Shh {
-		protocols = append(protocols, eth.whisper.Protocol())
+		//protocols = append(protocols, eth.whisper.Protocol())
 	}
 
 	eth.net = &p2p.Server{
diff --git a/eth/protocol.go b/eth/protocol.go
index 6d610a663..494c1c1bb 100644
--- a/eth/protocol.go
+++ b/eth/protocol.go
@@ -42,6 +42,7 @@ const (
 	ErrGenesisBlockMismatch
 	ErrNoStatusMsg
 	ErrExtraStatusMsg
+	ErrSuspendedPeer
 )
 
 var errorToString = map[int]string{
@@ -53,6 +54,7 @@ var errorToString = map[int]string{
 	ErrGenesisBlockMismatch:    "Genesis block mismatch",
 	ErrNoStatusMsg:             "No status message",
 	ErrExtraStatusMsg:          "Extra status message",
+	ErrSuspendedPeer:           "Suspended peer",
 }
 
 // ethProtocol represents the ethereum wire protocol
@@ -85,7 +87,7 @@ type chainManager interface {
 type blockPool interface {
 	AddBlockHashes(next func() (common.Hash, bool), peerId string)
 	AddBlock(block *types.Block, peerId string)
-	AddPeer(td *big.Int, currentBlock common.Hash, peerId string, requestHashes func(common.Hash) error, requestBlocks func([]common.Hash) error, peerError func(*errs.Error)) (best bool)
+	AddPeer(td *big.Int, currentBlock common.Hash, peerId string, requestHashes func(common.Hash) error, requestBlocks func([]common.Hash) error, peerError func(*errs.Error)) (best bool, suspended bool)
 	RemovePeer(peerId string)
 }
 
@@ -211,8 +213,7 @@ func (self *ethProtocol) handle() error {
 
 		var i int
 		iter := func() (hash common.Hash, ok bool) {
-			var h common.Hash
-			err := msgStream.Decode(&h)
+			err := msgStream.Decode(&hash)
 			if err == rlp.EOL {
 				return common.Hash{}, false
 			} else if err != nil {
@@ -288,7 +289,7 @@ func (self *ethProtocol) handle() error {
 		// to simplify backend interface adding a new block
 		// uses AddPeer followed by AddBlock only if peer is the best peer
 		// (or selected as new best peer)
-		if self.blockPool.AddPeer(request.TD, hash, self.id, self.requestBlockHashes, self.requestBlocks, self.protoErrorDisconnect) {
+		if best, _ := self.blockPool.AddPeer(request.TD, hash, self.id, self.requestBlockHashes, self.requestBlocks, self.protoErrorDisconnect); best {
 			self.blockPool.AddBlock(request.Block, self.id)
 		}
 
@@ -334,9 +335,12 @@ func (self *ethProtocol) handleStatus() error {
 		return self.protoError(ErrProtocolVersionMismatch, "%d (!= %d)", status.ProtocolVersion, self.protocolVersion)
 	}
 
-	self.peer.Infof("Peer is [eth] capable (%d/%d). TD=%v H=%x\n", status.ProtocolVersion, status.NetworkId, status.TD, status.CurrentBlock[:4])
+	_, suspended := self.blockPool.AddPeer(status.TD, status.CurrentBlock, self.id, self.requestBlockHashes, self.requestBlocks, self.protoErrorDisconnect)
+	if suspended {
+		return self.protoError(ErrSuspendedPeer, "")
+	}
 
-	self.blockPool.AddPeer(status.TD, status.CurrentBlock, self.id, self.requestBlockHashes, self.requestBlocks, self.protoErrorDisconnect)
+	self.peer.Infof("Peer is [eth] capable (%d/%d). TD=%v H=%x\n", status.ProtocolVersion, status.NetworkId, status.TD, status.CurrentBlock[:4])
 
 	return nil
 }
diff --git a/eth/protocol_test.go b/eth/protocol_test.go
index 7620b3854..8ca6d1be6 100644
--- a/eth/protocol_test.go
+++ b/eth/protocol_test.go
@@ -41,17 +41,10 @@ type testChainManager struct {
 type testBlockPool struct {
 	addBlockHashes func(next func() (common.Hash, bool), peerId string)
 	addBlock       func(block *types.Block, peerId string) (err error)
-	addPeer        func(td *big.Int, currentBlock common.Hash, peerId string, requestHashes func(common.Hash) error, requestBlocks func([]common.Hash) error, peerError func(*errs.Error)) (best bool)
+	addPeer        func(td *big.Int, currentBlock common.Hash, peerId string, requestHashes func(common.Hash) error, requestBlocks func([]common.Hash) error, peerError func(*errs.Error)) (best bool, suspended bool)
 	removePeer     func(peerId string)
 }
 
-// func (self *testTxPool) GetTransactions() (txs []*types.Transaction) {
-// 	if self.getTransactions != nil {
-// 		txs = self.getTransactions()
-// 	}
-// 	return
-// }
-
 func (self *testTxPool) AddTransactions(txs []*types.Transaction) {
 	if self.addTransactions != nil {
 		self.addTransactions(txs)
@@ -93,9 +86,9 @@ func (self *testBlockPool) AddBlock(block *types.Block, peerId string) {
 	}
 }
 
-func (self *testBlockPool) AddPeer(td *big.Int, currentBlock common.Hash, peerId string, requestBlockHashes func(common.Hash) error, requestBlocks func([]common.Hash) error, peerError func(*errs.Error)) (best bool) {
+func (self *testBlockPool) AddPeer(td *big.Int, currentBlock common.Hash, peerId string, requestBlockHashes func(common.Hash) error, requestBlocks func([]common.Hash) error, peerError func(*errs.Error)) (best bool, suspended bool) {
 	if self.addPeer != nil {
-		best = self.addPeer(td, currentBlock, peerId, requestBlockHashes, requestBlocks, peerError)
+		best, suspended = self.addPeer(td, currentBlock, peerId, requestBlockHashes, requestBlocks, peerError)
 	}
 	return
 }
diff --git a/eth/wallet.go b/eth/wallet.go
deleted file mode 100644
index 9ec834309..000000000
--- a/eth/wallet.go
+++ /dev/null
@@ -1,80 +0,0 @@
-package eth
-
-/*
-import (
-	"crypto/ecdsa"
-	"errors"
-	"math/big"
-
-	"github.com/ethereum/go-ethereum/core"
-	"github.com/ethereum/go-ethereum/core/types"
-)
-
-type Account struct {
-	w *Wallet
-}
-
-func (self *Account) Transact(to *Account, value, gas, price *big.Int, data []byte) error {
-	return self.w.transact(self, to, value, gas, price, data)
-}
-
-func (self *Account) Address() []byte {
-	return nil
-}
-
-func (self *Account) PrivateKey() *ecdsa.PrivateKey {
-	return nil
-}
-
-type Wallet struct{}
-
-func NewWallet() *Wallet {
-	return &Wallet{}
-}
-
-func (self *Wallet) GetAccount(i int) *Account {
-}
-
-func (self *Wallet) transact(from, to *Account, value, gas, price *big.Int, data []byte) error {
-	if from.PrivateKey() == nil {
-		return errors.New("accounts is not owned (no private key available)")
-	}
-
-	var createsContract bool
-	if to == nil {
-		createsContract = true
-	}
-
-	var msg *types.Transaction
-	if contractCreation {
-		msg = types.NewContractCreationTx(value, gas, price, data)
-	} else {
-		msg = types.NewTransactionMessage(to.Address(), value, gas, price, data)
-	}
-
-	state := self.chainManager.TransState()
-	nonce := state.GetNonce(key.Address())
-
-	msg.SetNonce(nonce)
-	msg.SignECDSA(from.PriateKey())
-
-	// Do some pre processing for our "pre" events  and hooks
-	block := self.chainManager.NewBlock(from.Address())
-	coinbase := state.GetOrNewStateObject(from.Address())
-	coinbase.SetGasPool(block.GasLimit())
-	self.blockManager.ApplyTransactions(coinbase, state, block, types.Transactions{tx}, true)
-
-	err := self.obj.TxPool().Add(tx)
-	if err != nil {
-		return nil, err
-	}
-	state.SetNonce(key.Address(), nonce+1)
-
-	if contractCreation {
-		addr := core.AddressFromMessage(tx)
-		pipelogger.Infof("Contract addr %x\n", addr)
-	}
-
-	return tx, nil
-}
-*/
diff --git a/event/filter/eth_filter.go b/event/filter/eth_filter.go
index cb75d7e1a..1abd48389 100644
--- a/event/filter/eth_filter.go
+++ b/event/filter/eth_filter.go
@@ -48,7 +48,9 @@ func (self *FilterManager) InstallFilter(filter *core.Filter) (id int) {
 func (self *FilterManager) UninstallFilter(id int) {
 	self.filterMu.Lock()
 	defer self.filterMu.Unlock()
-	delete(self.filters, id)
+	if _, ok := self.filters[id]; ok {
+		delete(self.filters, id)
+	}
 }
 
 // GetFilter retrieves a filter installed using InstallFilter.
@@ -62,8 +64,9 @@ func (self *FilterManager) GetFilter(id int) *core.Filter {
 func (self *FilterManager) filterLoop() {
 	// Subscribe to events
 	events := self.eventMux.Subscribe(
-		core.PendingBlockEvent{},
+		//core.PendingBlockEvent{},
 		core.ChainEvent{},
+		core.TxPreEvent{},
 		state.Logs(nil))
 
 out:
@@ -82,11 +85,11 @@ out:
 				}
 				self.filterMu.RUnlock()
 
-			case core.PendingBlockEvent:
+			case core.TxPreEvent:
 				self.filterMu.RLock()
 				for _, filter := range self.filters {
 					if filter.PendingCallback != nil {
-						filter.PendingCallback(event.Block, event.Logs)
+						filter.PendingCallback(event.Tx)
 					}
 				}
 				self.filterMu.RUnlock()
diff --git a/miner/agent.go b/miner/agent.go
index 6865d5a08..64491e04c 100644
--- a/miner/agent.go
+++ b/miner/agent.go
@@ -79,3 +79,7 @@ func (self *CpuMiner) mine(block *types.Block) {
 		self.returnCh <- Work{block.Number().Uint64(), nonce, mixDigest, seedHash}
 	}
 }
+
+func (self *CpuMiner) GetHashRate() int64 {
+	return self.pow.GetHashrate()
+}
diff --git a/miner/worker.go b/miner/worker.go
index 63d1bfa0b..ae6782aca 100644
--- a/miner/worker.go
+++ b/miner/worker.go
@@ -57,7 +57,7 @@ type Agent interface {
 	SetWorkCh(chan<- Work)
 	Stop()
 	Start()
-	Pow() pow.PoW
+	GetHashRate() int64
 }
 
 type worker struct {
@@ -272,7 +272,7 @@ func (self *worker) commitTransaction(tx *types.Transaction) error {
 func (self *worker) HashRate() int64 {
 	var tot int64
 	for _, agent := range self.agents {
-		tot += agent.Pow().GetHashrate()
+		tot += agent.GetHashRate()
 	}
 
 	return tot
diff --git a/rpc/api.go b/rpc/api.go
index 39a6b8f5b..34d4ff0fc 100644
--- a/rpc/api.go
+++ b/rpc/api.go
@@ -2,491 +2,49 @@ package rpc
 
 import (
 	"encoding/json"
-	"fmt"
 	"math/big"
 	"path"
-	"strings"
 	"sync"
-	"time"
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core"
-	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/ethdb"
-	"github.com/ethereum/go-ethereum/event"
-	"github.com/ethereum/go-ethereum/event/filter"
-	"github.com/ethereum/go-ethereum/state"
 	"github.com/ethereum/go-ethereum/xeth"
 )
 
-var (
-	defaultGasPrice  = big.NewInt(150000000000)
-	defaultGas       = big.NewInt(500000)
-	filterTickerTime = 5 * time.Minute
-)
-
 type EthereumApi struct {
 	eth    *xeth.XEth
 	xethMu sync.RWMutex
-	mux    *event.TypeMux
-
-	quit          chan struct{}
-	filterManager *filter.FilterManager
-
-	logMut sync.RWMutex
-	logs   map[int]*logFilter
-
-	messagesMut sync.RWMutex
-	messages    map[int]*whisperFilter
-	// Register keeps a list of accounts and transaction data
-	regmut   sync.Mutex
-	register map[string][]*NewTxArgs
-
-	db common.Database
+	db     common.Database
 }
 
 func NewEthereumApi(eth *xeth.XEth, dataDir string) *EthereumApi {
+	// What about when dataDir is empty?
 	db, _ := ethdb.NewLDBDatabase(path.Join(dataDir, "dapps"))
 	api := &EthereumApi{
-		eth:           eth,
-		mux:           eth.Backend().EventMux(),
-		quit:          make(chan struct{}),
-		filterManager: filter.NewFilterManager(eth.Backend().EventMux()),
-		logs:          make(map[int]*logFilter),
-		messages:      make(map[int]*whisperFilter),
-		db:            db,
+		eth: eth,
+		db:  db,
 	}
-	go api.filterManager.Start()
-	go api.start()
 
 	return api
 }
 
-func (self *EthereumApi) xethWithStateNum(num int64) *xeth.XEth {
-	chain := self.xeth().Backend().ChainManager()
-	var block *types.Block
+func (self *EthereumApi) xeth() *xeth.XEth {
+	self.xethMu.RLock()
+	defer self.xethMu.RUnlock()
 
-	if num < 0 {
-		num = chain.CurrentBlock().Number().Int64() + num + 1
-	}
-	block = chain.GetBlockByNumber(uint64(num))
-
-	var st *state.StateDB
-	if block != nil {
-		st = state.New(block.Root(), self.xeth().Backend().StateDb())
-	} else {
-		st = chain.State()
-	}
-	return self.xeth().WithState(st)
+	return self.eth
 }
 
-func (self *EthereumApi) getStateWithNum(num int64) *xeth.State {
-	return self.xethWithStateNum(num).State()
-}
-
-func (self *EthereumApi) start() {
-	timer := time.NewTicker(2 * time.Second)
-done:
-	for {
-		select {
-		case <-timer.C:
-			self.logMut.Lock()
-			self.messagesMut.Lock()
-			for id, filter := range self.logs {
-				if time.Since(filter.timeout) > filterTickerTime {
-					self.filterManager.UninstallFilter(id)
-					delete(self.logs, id)
-				}
-			}
-
-			for id, filter := range self.messages {
-				if time.Since(filter.timeout) > filterTickerTime {
-					self.xeth().Whisper().Unwatch(id)
-					delete(self.messages, id)
-				}
-			}
-			self.messagesMut.Unlock()
-			self.logMut.Unlock()
-		case <-self.quit:
-			break done
-		}
-	}
-}
-
-func (self *EthereumApi) stop() {
-	close(self.quit)
-}
-
-// func (self *EthereumApi) Register(args string, reply *interface{}) error {
-// 	self.regmut.Lock()
-// 	defer self.regmut.Unlock()
-
-// 	if _, ok := self.register[args]; ok {
-// 		self.register[args] = nil // register with empty
-// 	}
-// 	return nil
-// }
-
-// func (self *EthereumApi) Unregister(args string, reply *interface{}) error {
-// 	self.regmut.Lock()
-// 	defer self.regmut.Unlock()
-
-// 	delete(self.register, args)
-
-// 	return nil
-// }
-
-// func (self *EthereumApi) WatchTx(args string, reply *interface{}) error {
-// 	self.regmut.Lock()
-// 	defer self.regmut.Unlock()
-
-// 	txs := self.register[args]
-// 	self.register[args] = nil
-
-// 	*reply = txs
-// 	return nil
-// }
-
-func (self *EthereumApi) NewFilter(args *FilterOptions, reply *interface{}) error {
-	var id int
-	filter := core.NewFilter(self.xeth().Backend())
-	filter.SetOptions(toFilterOptions(args))
-	filter.LogsCallback = func(logs state.Logs) {
-		self.logMut.Lock()
-		defer self.logMut.Unlock()
-
-		self.logs[id].add(logs...)
-	}
-	id = self.filterManager.InstallFilter(filter)
-	self.logs[id] = &logFilter{timeout: time.Now()}
-
-	*reply = common.ToHex(big.NewInt(int64(id)).Bytes())
-
-	return nil
-}
-
-func (self *EthereumApi) UninstallFilter(id int, reply *interface{}) error {
-	if _, ok := self.logs[id]; ok {
-		delete(self.logs, id)
-	}
-
-	self.filterManager.UninstallFilter(id)
-	*reply = true
-	return nil
-}
-
-func (self *EthereumApi) NewFilterString(args *FilterStringArgs, reply *interface{}) error {
-	var id int
-	filter := core.NewFilter(self.xeth().Backend())
-
-	callback := func(block *types.Block, logs state.Logs) {
-		self.logMut.Lock()
-		defer self.logMut.Unlock()
-
-		for _, log := range logs {
-			self.logs[id].add(log)
-		}
-		self.logs[id].add(&state.StateLog{})
-	}
-
-	switch args.Word {
-	case "pending":
-		filter.PendingCallback = callback
-	case "latest":
-		filter.BlockCallback = callback
-	default:
-		return NewValidationError("Word", "Must be `latest` or `pending`")
-	}
-
-	id = self.filterManager.InstallFilter(filter)
-	self.logs[id] = &logFilter{timeout: time.Now()}
-	*reply = common.ToHex(big.NewInt(int64(id)).Bytes())
-
-	return nil
-}
-
-func (self *EthereumApi) FilterChanged(id int, reply *interface{}) error {
-	self.logMut.Lock()
-	defer self.logMut.Unlock()
-
-	if self.logs[id] != nil {
-		*reply = toLogs(self.logs[id].get())
-	}
-
-	return nil
-}
-
-func (self *EthereumApi) Logs(id int, reply *interface{}) error {
-	self.logMut.Lock()
-	defer self.logMut.Unlock()
-
-	filter := self.filterManager.GetFilter(id)
-	if filter != nil {
-		*reply = toLogs(filter.Find())
-	}
-
-	return nil
-}
-
-func (self *EthereumApi) AllLogs(args *FilterOptions, reply *interface{}) error {
-	filter := core.NewFilter(self.xeth().Backend())
-	filter.SetOptions(toFilterOptions(args))
-
-	*reply = toLogs(filter.Find())
-
-	return nil
-}
-
-func (p *EthereumApi) Transact(args *NewTxArgs, reply *interface{}) (err error) {
-	// TODO if no_private_key then
-	//if _, exists := p.register[args.From]; exists {
-	//	p.register[args.From] = append(p.register[args.From], args)
-	//} else {
-	/*
-		account := accounts.Get(common.FromHex(args.From))
-		if account != nil {
-			if account.Unlocked() {
-				if !unlockAccount(account) {
-					return
-				}
-			}
-
-			result, _ := account.Transact(common.FromHex(args.To), common.FromHex(args.Value), common.FromHex(args.Gas), common.FromHex(args.GasPrice), common.FromHex(args.Data))
-			if len(result) > 0 {
-				*reply = common.ToHex(result)
-			}
-		} else if _, exists := p.register[args.From]; exists {
-			p.register[ags.From] = append(p.register[args.From], args)
-		}
-	*/
-
-	if err := args.requirements(); err != nil {
-		return err
-	}
-
-	// TODO: align default values to have the same type, e.g. not depend on
-	// common.Value conversions later on
-	if args.Gas.Cmp(big.NewInt(0)) == 0 {
-		args.Gas = defaultGas
-	}
-
-	if args.GasPrice.Cmp(big.NewInt(0)) == 0 {
-		args.GasPrice = defaultGasPrice
-	}
-
-	*reply, err = p.xeth().Transact(args.From, args.To, args.Value.String(), args.Gas.String(), args.GasPrice.String(), args.Data)
-	if err != nil {
-		fmt.Println("err:", err)
-		return err
-	}
-
-	return nil
-}
-
-func (p *EthereumApi) Call(args *NewTxArgs, reply *interface{}) error {
-	result, err := p.xethWithStateNum(args.BlockNumber).Call(args.From, args.To, args.Value.String(), args.Gas.String(), args.GasPrice.String(), args.Data)
-	if err != nil {
-		return err
-	}
-
-	*reply = result
-	return nil
-}
-
-func (p *EthereumApi) GetBalance(args *GetBalanceArgs, reply *interface{}) error {
-	if err := args.requirements(); err != nil {
-		return err
-	}
-	state := p.getStateWithNum(args.BlockNumber).SafeGet(args.Address)
-	*reply = common.ToHex(state.Balance().Bytes())
-	return nil
-}
-
-func (p *EthereumApi) GetStorage(args *GetStorageArgs, reply *interface{}) error {
-	if err := args.requirements(); err != nil {
-		return err
-	}
-	*reply = p.getStateWithNum(args.BlockNumber).SafeGet(args.Address).Storage()
-	return nil
-}
-
-func (p *EthereumApi) GetStorageAt(args *GetStorageAtArgs, reply *interface{}) error {
-	if err := args.requirements(); err != nil {
-		return err
-	}
-	state := p.getStateWithNum(args.BlockNumber).SafeGet(args.Address)
-
-	value := state.StorageString(args.Key)
-	var hx string
-	if strings.Index(args.Key, "0x") == 0 {
-		hx = string([]byte(args.Key)[2:])
-	} else {
-		// Convert the incoming string (which is a bigint) into hex
-		i, _ := new(big.Int).SetString(args.Key, 10)
-		hx = common.Bytes2Hex(i.Bytes())
-	}
-	rpclogger.Debugf("GetStateAt(%s, %s)\n", args.Address, hx)
-	*reply = map[string]string{args.Key: value.Str()}
-	return nil
-}
-
-func (p *EthereumApi) GetTxCountAt(args *GetTxCountArgs, reply *interface{}) error {
-	err := args.requirements()
-	if err != nil {
-		return err
-	}
-	*reply = p.xethWithStateNum(args.BlockNumber).TxCountAt(args.Address)
-	return nil
-}
-
-func (p *EthereumApi) GetData(args *GetDataArgs, reply *interface{}) error {
-	if err := args.requirements(); err != nil {
-		return err
-	}
-	*reply = p.xethWithStateNum(args.BlockNumber).CodeAt(args.Address)
-	return nil
-}
-
-func (p *EthereumApi) GetCompilers(reply *interface{}) error {
-	c := []string{""}
-	*reply = c
-	return nil
-}
-
-func (p *EthereumApi) DbPut(args *DbArgs, reply *interface{}) error {
-	if err := args.requirements(); err != nil {
-		return err
-	}
-
-	p.db.Put([]byte(args.Database+args.Key), []byte(args.Value))
-	*reply = true
-	return nil
-}
-
-func (p *EthereumApi) DbGet(args *DbArgs, reply *interface{}) error {
-	if err := args.requirements(); err != nil {
-		return err
-	}
-
-	res, _ := p.db.Get([]byte(args.Database + args.Key))
-	*reply = string(res)
-	return nil
-}
-
-func (p *EthereumApi) NewWhisperIdentity(reply *interface{}) error {
-	*reply = p.xeth().Whisper().NewIdentity()
-	return nil
-}
-
-// func (p *EthereumApi) RemoveWhisperIdentity(args *WhisperIdentityArgs, reply *interface{}) error {
-// 	*reply = p.xeth().Whisper().RemoveIdentity(args.Identity)
-// 	return nil
-// }
-
-func (p *EthereumApi) NewWhisperFilter(args *WhisperFilterArgs, reply *interface{}) error {
-	var id int
-	opts := new(xeth.Options)
-	opts.From = args.From
-	opts.To = args.To
-	opts.Topics = args.Topics
-	opts.Fn = func(msg xeth.WhisperMessage) {
-		p.messagesMut.Lock()
-		defer p.messagesMut.Unlock()
-		p.messages[id].add(msg) // = append(p.messages[id], msg)
-	}
-	id = p.xeth().Whisper().Watch(opts)
-	p.messages[id] = &whisperFilter{timeout: time.Now()}
-	*reply = common.ToHex(big.NewInt(int64(id)).Bytes())
-	return nil
-}
-
-func (p *EthereumApi) UninstallWhisperFilter(id int, reply *interface{}) error {
-	delete(p.messages, id)
-	*reply = true
-	return nil
-}
-
-func (self *EthereumApi) MessagesChanged(id int, reply *interface{}) error {
-	self.messagesMut.Lock()
-	defer self.messagesMut.Unlock()
-
-	if self.messages[id] != nil {
-		*reply = self.messages[id].get()
-	}
-
-	return nil
-}
-
-func (p *EthereumApi) WhisperPost(args *WhisperMessageArgs, reply *interface{}) error {
-	err := p.xeth().Whisper().Post(args.Payload, args.To, args.From, args.Topics, args.Priority, args.Ttl)
-	if err != nil {
-		return err
-	}
-
-	*reply = true
-	return nil
-}
-
-func (p *EthereumApi) HasWhisperIdentity(args string, reply *interface{}) error {
-	*reply = p.xeth().Whisper().HasIdentity(args)
-	return nil
-}
-
-func (p *EthereumApi) WhisperMessages(id int, reply *interface{}) error {
-	*reply = p.xeth().Whisper().Messages(id)
-	return nil
-}
-
-func (p *EthereumApi) GetTransactionByHash(hash string, reply *interface{}) error {
-	tx := p.xeth().EthTransactionByHash(hash)
-	if tx != nil {
-		*reply = NewTransactionRes(tx)
-	}
-	return nil
-}
-
-func (p *EthereumApi) GetBlockByHash(blockhash string, includetx bool) (*BlockRes, error) {
-	block := p.xeth().EthBlockByHash(blockhash)
-	br := NewBlockRes(block)
-	br.fullTx = includetx
-	return br, nil
-}
-
-func (p *EthereumApi) GetBlockByNumber(blocknum int64, includetx bool) (*BlockRes, error) {
-	block := p.xeth().EthBlockByNumber(blocknum)
-	br := NewBlockRes(block)
-	br.fullTx = includetx
-	return br, nil
-}
-
-func (p *EthereumApi) GetBlockTransactionCountByHash(blockhash string) (int64, error) {
-	block := p.xeth().EthBlockByHash(blockhash)
-	br := NewBlockRes(block)
-	return int64(len(br.Transactions)), nil
-}
-
-func (p *EthereumApi) GetBlockTransactionCountByNumber(blocknum int64) (int64, error) {
-	block := p.xeth().EthBlockByNumber(blocknum)
-	br := NewBlockRes(block)
-	return int64(len(br.Transactions)), nil
-}
-
-func (p *EthereumApi) GetBlockUncleCountByHash(blockhash string) (int64, error) {
-	block := p.xeth().EthBlockByHash(blockhash)
-	br := NewBlockRes(block)
-	return int64(len(br.Uncles)), nil
-}
-
-func (p *EthereumApi) GetBlockUncleCountByNumber(blocknum int64) (int64, error) {
-	block := p.xeth().EthBlockByNumber(blocknum)
-	br := NewBlockRes(block)
-	return int64(len(br.Uncles)), nil
+func (self *EthereumApi) xethAtStateNum(num int64) *xeth.XEth {
+	return self.xeth().AtStateNum(num)
 }
 
 func (p *EthereumApi) GetRequestReply(req *RpcRequest, reply *interface{}) error {
 	// Spec at https://github.com/ethereum/wiki/wiki/Generic-JSON-RPC
 	rpclogger.Debugf("%s %s", req.Method, req.Params)
+
 	switch req.Method {
 	case "web3_sha3":
 		args := new(Sha3Args)
@@ -501,7 +59,8 @@ func (p *EthereumApi) GetRequestReply(req *RpcRequest, reply *interface{}) error
 	case "net_listening":
 		*reply = p.xeth().IsListening()
 	case "net_peerCount":
-		*reply = common.ToHex(big.NewInt(int64(p.xeth().PeerCount())).Bytes())
+		v := p.xeth().PeerCount()
+		*reply = common.ToHex(big.NewInt(int64(v)).Bytes())
 	case "eth_coinbase":
 		// TODO handling of empty coinbase due to lack of accounts
 		res := p.xeth().Coinbase()
@@ -513,97 +72,131 @@ func (p *EthereumApi) GetRequestReply(req *RpcRequest, reply *interface{}) error
 	case "eth_mining":
 		*reply = p.xeth().IsMining()
 	case "eth_gasPrice":
-		*reply = common.ToHex(defaultGasPrice.Bytes())
+		v := p.xeth().DefaultGas()
+		*reply = common.ToHex(v.Bytes())
 	case "eth_accounts":
 		*reply = p.xeth().Accounts()
 	case "eth_blockNumber":
-		*reply = common.ToHex(p.xeth().Backend().ChainManager().CurrentBlock().Number().Bytes())
+		v := p.xeth().Backend().ChainManager().CurrentBlock().Number()
+		*reply = common.ToHex(v.Bytes())
 	case "eth_getBalance":
 		args := new(GetBalanceArgs)
 		if err := json.Unmarshal(req.Params, &args); err != nil {
 			return err
 		}
-		return p.GetBalance(args, reply)
+
+		if err := args.requirements(); err != nil {
+			return err
+		}
+
+		v := p.xethAtStateNum(args.BlockNumber).State().SafeGet(args.Address).Balance()
+		*reply = common.ToHex(v.Bytes())
 	case "eth_getStorage", "eth_storageAt":
 		args := new(GetStorageArgs)
 		if err := json.Unmarshal(req.Params, &args); err != nil {
 			return err
 		}
-		return p.GetStorage(args, reply)
+
+		if err := args.requirements(); err != nil {
+			return err
+		}
+
+		*reply = p.xethAtStateNum(args.BlockNumber).State().SafeGet(args.Address).Storage()
 	case "eth_getStorageAt":
 		args := new(GetStorageAtArgs)
 		if err := json.Unmarshal(req.Params, &args); err != nil {
 			return err
 		}
-		return p.GetStorageAt(args, reply)
+		if err := args.requirements(); err != nil {
+			return err
+		}
+
+		state := p.xethAtStateNum(args.BlockNumber).State().SafeGet(args.Address)
+		value := state.StorageString(args.Key)
+
+		*reply = common.Bytes2Hex(value.Bytes())
 	case "eth_getTransactionCount":
 		args := new(GetTxCountArgs)
 		if err := json.Unmarshal(req.Params, &args); err != nil {
 			return err
 		}
-		return p.GetTxCountAt(args, reply)
+
+		err := args.requirements()
+		if err != nil {
+			return err
+		}
+
+		*reply = p.xethAtStateNum(args.BlockNumber).TxCountAt(args.Address)
 	case "eth_getBlockTransactionCountByHash":
 		args := new(GetBlockByHashArgs)
 		if err := json.Unmarshal(req.Params, &args); err != nil {
 			return err
 		}
 
-		v, err := p.GetBlockTransactionCountByHash(args.BlockHash)
-		if err != nil {
-			return err
-		}
-		*reply = common.ToHex(big.NewInt(v).Bytes())
+		block := NewBlockRes(p.xeth().EthBlockByHash(args.BlockHash))
+		*reply = common.ToHex(big.NewInt(int64(len(block.Transactions))).Bytes())
 	case "eth_getBlockTransactionCountByNumber":
 		args := new(GetBlockByNumberArgs)
 		if err := json.Unmarshal(req.Params, &args); err != nil {
 			return err
 		}
 
-		v, err := p.GetBlockTransactionCountByNumber(args.BlockNumber)
-		if err != nil {
-			return err
-		}
-		*reply = common.ToHex(big.NewInt(v).Bytes())
+		block := NewBlockRes(p.xeth().EthBlockByNumber(args.BlockNumber))
+		*reply = common.ToHex(big.NewInt(int64(len(block.Transactions))).Bytes())
 	case "eth_getUncleCountByBlockHash":
 		args := new(GetBlockByHashArgs)
 		if err := json.Unmarshal(req.Params, &args); err != nil {
 			return err
 		}
 
-		v, err := p.GetBlockUncleCountByHash(args.BlockHash)
-		if err != nil {
-			return err
-		}
-		*reply = common.ToHex(big.NewInt(v).Bytes())
+		block := p.xeth().EthBlockByHash(args.BlockHash)
+		br := NewBlockRes(block)
+		*reply = common.ToHex(big.NewInt(int64(len(br.Uncles))).Bytes())
 	case "eth_getUncleCountByBlockNumber":
 		args := new(GetBlockByNumberArgs)
 		if err := json.Unmarshal(req.Params, &args); err != nil {
 			return err
 		}
 
-		v, err := p.GetBlockUncleCountByNumber(args.BlockNumber)
-		if err != nil {
-			return err
-		}
-		*reply = common.ToHex(big.NewInt(v).Bytes())
+		block := p.xeth().EthBlockByNumber(args.BlockNumber)
+		br := NewBlockRes(block)
+		*reply = common.ToHex(big.NewInt(int64(len(br.Uncles))).Bytes())
 	case "eth_getData", "eth_getCode":
 		args := new(GetDataArgs)
 		if err := json.Unmarshal(req.Params, &args); err != nil {
 			return err
 		}
-		return p.GetData(args, reply)
+		if err := args.requirements(); err != nil {
+			return err
+		}
+		*reply = p.xethAtStateNum(args.BlockNumber).CodeAt(args.Address)
 	case "eth_sendTransaction", "eth_transact":
 		args := new(NewTxArgs)
 		if err := json.Unmarshal(req.Params, &args); err != nil {
 			return err
 		}
-		return p.Transact(args, reply)
+
+		if err := args.requirements(); err != nil {
+			return err
+		}
+
+		v, err := p.xeth().Transact(args.From, args.To, args.Value.String(), args.Gas.String(), args.GasPrice.String(), args.Data)
+		if err != nil {
+			return err
+		}
+		*reply = v
 	case "eth_call":
 		args := new(NewTxArgs)
 		if err := json.Unmarshal(req.Params, &args); err != nil {
 			return err
 		}
-		return p.Call(args, reply)
+
+		v, err := p.xethAtStateNum(args.BlockNumber).Call(args.From, args.To, args.Value.String(), args.Gas.String(), args.GasPrice.String(), args.Data)
+		if err != nil {
+			return err
+		}
+
+		*reply = v
 	case "eth_flush":
 		return NewNotImplementedError(req.Method)
 	case "eth_getBlockByHash":
@@ -612,52 +205,55 @@ func (p *EthereumApi) GetRequestReply(req *RpcRequest, reply *interface{}) error
 			return err
 		}
 
-		v, err := p.GetBlockByHash(args.BlockHash, args.Transactions)
-		if err != nil {
-			return err
-		}
-		*reply = v
+		block := p.xeth().EthBlockByHash(args.BlockHash)
+		br := NewBlockRes(block)
+		br.fullTx = args.IncludeTxs
+
+		*reply = br
 	case "eth_getBlockByNumber":
 		args := new(GetBlockByNumberArgs)
 		if err := json.Unmarshal(req.Params, &args); err != nil {
 			return err
 		}
 
-		v, err := p.GetBlockByNumber(args.BlockNumber, args.Transactions)
-		if err != nil {
-			return err
-		}
-		*reply = v
+		block := p.xeth().EthBlockByNumber(args.BlockNumber)
+		br := NewBlockRes(block)
+		br.fullTx = args.IncludeTxs
+
+		*reply = br
 	case "eth_getTransactionByHash":
 		// HashIndexArgs used, but only the "Hash" part we need.
 		args := new(HashIndexArgs)
 		if err := json.Unmarshal(req.Params, &args); err != nil {
 		}
-		return p.GetTransactionByHash(args.Hash, reply)
+		tx := p.xeth().EthTransactionByHash(args.Hash)
+		if tx != nil {
+			*reply = NewTransactionRes(tx)
+		}
 	case "eth_getTransactionByBlockHashAndIndex":
 		args := new(HashIndexArgs)
 		if err := json.Unmarshal(req.Params, &args); err != nil {
 			return err
 		}
 
-		v, err := p.GetBlockByHash(args.Hash, true)
-		if err != nil {
-			return err
-		}
-		if args.Index > int64(len(v.Transactions)) || args.Index < 0 {
+		block := p.xeth().EthBlockByHash(args.Hash)
+		br := NewBlockRes(block)
+		br.fullTx = true
+
+		if args.Index > int64(len(br.Transactions)) || args.Index < 0 {
 			return NewValidationError("Index", "does not exist")
 		}
-		*reply = v.Transactions[args.Index]
+		*reply = br.Transactions[args.Index]
 	case "eth_getTransactionByBlockNumberAndIndex":
 		args := new(BlockNumIndexArgs)
 		if err := json.Unmarshal(req.Params, &args); err != nil {
 			return err
 		}
 
-		v, err := p.GetBlockByNumber(args.BlockNumber, true)
-		if err != nil {
-			return err
-		}
+		block := p.xeth().EthBlockByNumber(args.BlockNumber)
+		v := NewBlockRes(block)
+		v.fullTx = true
+
 		if args.Index > int64(len(v.Transactions)) || args.Index < 0 {
 			return NewValidationError("Index", "does not exist")
 		}
@@ -668,18 +264,15 @@ func (p *EthereumApi) GetRequestReply(req *RpcRequest, reply *interface{}) error
 			return err
 		}
 
-		v, err := p.GetBlockByHash(args.Hash, false)
-		if err != nil {
-			return err
-		}
-		if args.Index > int64(len(v.Uncles)) || args.Index < 0 {
+		br := NewBlockRes(p.xeth().EthBlockByHash(args.Hash))
+
+		if args.Index > int64(len(br.Uncles)) || args.Index < 0 {
 			return NewValidationError("Index", "does not exist")
 		}
 
-		uncle, err := p.GetBlockByHash(v.Uncles[args.Index].Hex(), false)
-		if err != nil {
-			return err
-		}
+		uhash := br.Uncles[args.Index].Hex()
+		uncle := NewBlockRes(p.xeth().EthBlockByHash(uhash))
+
 		*reply = uncle
 	case "eth_getUncleByBlockNumberAndIndex":
 		args := new(BlockNumIndexArgs)
@@ -687,59 +280,68 @@ func (p *EthereumApi) GetRequestReply(req *RpcRequest, reply *interface{}) error
 			return err
 		}
 
-		v, err := p.GetBlockByNumber(args.BlockNumber, true)
-		if err != nil {
-			return err
-		}
+		block := p.xeth().EthBlockByNumber(args.BlockNumber)
+		v := NewBlockRes(block)
+		v.fullTx = true
+
 		if args.Index > int64(len(v.Uncles)) || args.Index < 0 {
 			return NewValidationError("Index", "does not exist")
 		}
 
-		uncle, err := p.GetBlockByHash(v.Uncles[args.Index].Hex(), false)
-		if err != nil {
-			return err
-		}
+		uhash := v.Uncles[args.Index].Hex()
+		uncle := NewBlockRes(p.xeth().EthBlockByHash(uhash))
+
 		*reply = uncle
 	case "eth_getCompilers":
-		return p.GetCompilers(reply)
+		c := []string{""}
+		*reply = c
 	case "eth_compileSolidity", "eth_compileLLL", "eth_compileSerpent":
 		return NewNotImplementedError(req.Method)
 	case "eth_newFilter":
-		args := new(FilterOptions)
+		args := new(BlockFilterArgs)
 		if err := json.Unmarshal(req.Params, &args); err != nil {
 			return err
 		}
-		return p.NewFilter(args, reply)
+
+		opts := toFilterOptions(args)
+		id := p.xeth().RegisterFilter(opts)
+		*reply = common.ToHex(big.NewInt(int64(id)).Bytes())
 	case "eth_newBlockFilter":
 		args := new(FilterStringArgs)
 		if err := json.Unmarshal(req.Params, &args); err != nil {
 			return err
 		}
-		return p.NewFilterString(args, reply)
+		if err := args.requirements(); err != nil {
+			return err
+		}
+
+		id := p.xeth().NewFilterString(args.Word)
+		*reply = common.ToHex(big.NewInt(int64(id)).Bytes())
 	case "eth_uninstallFilter":
 		args := new(FilterIdArgs)
 		if err := json.Unmarshal(req.Params, &args); err != nil {
 			return err
 		}
-		return p.UninstallFilter(args.Id, reply)
+		*reply = p.xeth().UninstallFilter(args.Id)
 	case "eth_getFilterChanges":
 		args := new(FilterIdArgs)
 		if err := json.Unmarshal(req.Params, &args); err != nil {
 			return err
 		}
-		return p.FilterChanged(args.Id, reply)
+		*reply = NewLogsRes(p.xeth().FilterChanged(args.Id))
 	case "eth_getFilterLogs":
 		args := new(FilterIdArgs)
 		if err := json.Unmarshal(req.Params, &args); err != nil {
 			return err
 		}
-		return p.Logs(args.Id, reply)
+		*reply = NewLogsRes(p.xeth().Logs(args.Id))
 	case "eth_getLogs":
-		args := new(FilterOptions)
+		args := new(BlockFilterArgs)
 		if err := json.Unmarshal(req.Params, &args); err != nil {
 			return err
 		}
-		return p.AllLogs(args, reply)
+		opts := toFilterOptions(args)
+		*reply = NewLogsRes(p.xeth().AllLogs(opts))
 	case "eth_getWork", "eth_submitWork":
 		return NewNotImplementedError(req.Method)
 	case "db_putString":
@@ -747,13 +349,25 @@ func (p *EthereumApi) GetRequestReply(req *RpcRequest, reply *interface{}) error
 		if err := json.Unmarshal(req.Params, &args); err != nil {
 			return err
 		}
-		return p.DbPut(args, reply)
+
+		if err := args.requirements(); err != nil {
+			return err
+		}
+
+		p.db.Put([]byte(args.Database+args.Key), []byte(args.Value))
+		*reply = true
 	case "db_getString":
 		args := new(DbArgs)
 		if err := json.Unmarshal(req.Params, &args); err != nil {
 			return err
 		}
-		return p.DbGet(args, reply)
+
+		if err := args.requirements(); err != nil {
+			return err
+		}
+
+		res, _ := p.db.Get([]byte(args.Database + args.Key))
+		*reply = string(res)
 	case "db_putHex", "db_getHex":
 		return NewNotImplementedError(req.Method)
 	case "shh_post":
@@ -761,21 +375,27 @@ func (p *EthereumApi) GetRequestReply(req *RpcRequest, reply *interface{}) error
 		if err := json.Unmarshal(req.Params, &args); err != nil {
 			return err
 		}
-		return p.WhisperPost(args, reply)
+
+		err := p.xeth().Whisper().Post(args.Payload, args.To, args.From, args.Topics, args.Priority, args.Ttl)
+		if err != nil {
+			return err
+		}
+
+		*reply = true
 	case "shh_newIdentity":
-		return p.NewWhisperIdentity(reply)
+		*reply = p.xeth().Whisper().NewIdentity()
 	// case "shh_removeIdentity":
 	// 	args := new(WhisperIdentityArgs)
 	// 	if err := json.Unmarshal(req.Params, &args); err != nil {
 	// 		return err
 	// 	}
-	// 	return p.RemoveWhisperIdentity(args, reply)
+	// 	*reply = p.xeth().Whisper().RemoveIdentity(args.Identity)
 	case "shh_hasIdentity":
 		args := new(WhisperIdentityArgs)
 		if err := json.Unmarshal(req.Params, &args); err != nil {
 			return err
 		}
-		return p.HasWhisperIdentity(args.Identity, reply)
+		*reply = p.xeth().Whisper().HasIdentity(args.Identity)
 	case "shh_newGroup", "shh_addToGroup":
 		return NewNotImplementedError(req.Method)
 	case "shh_newFilter":
@@ -783,43 +403,49 @@ func (p *EthereumApi) GetRequestReply(req *RpcRequest, reply *interface{}) error
 		if err := json.Unmarshal(req.Params, &args); err != nil {
 			return err
 		}
-		return p.NewWhisperFilter(args, reply)
+		opts := new(xeth.Options)
+		opts.From = args.From
+		opts.To = args.To
+		opts.Topics = args.Topics
+		id := p.xeth().NewWhisperFilter(opts)
+		*reply = common.ToHex(big.NewInt(int64(id)).Bytes())
 	case "shh_uninstallFilter":
 		args := new(FilterIdArgs)
 		if err := json.Unmarshal(req.Params, &args); err != nil {
 			return err
 		}
-		return p.UninstallWhisperFilter(args.Id, reply)
+		*reply = p.xeth().UninstallWhisperFilter(args.Id)
 	case "shh_getFilterChanges":
 		args := new(FilterIdArgs)
 		if err := json.Unmarshal(req.Params, &args); err != nil {
 			return err
 		}
-		return p.MessagesChanged(args.Id, reply)
+		*reply = p.xeth().MessagesChanged(args.Id)
 	case "shh_getMessages":
 		args := new(FilterIdArgs)
 		if err := json.Unmarshal(req.Params, &args); err != nil {
 			return err
 		}
-		return p.WhisperMessages(args.Id, reply)
+		*reply = p.xeth().Whisper().Messages(args.Id)
 	// case "eth_register":
-	// 	args, err := req.ToRegisterArgs()
-	// 	if err != nil {
+	// 	// Placeholder for actual type
+	// 	args := new(HashIndexArgs)
+	// 	if err := json.Unmarshal(req.Params, &args); err != nil {
 	// 		return err
 	// 	}
-	// 	return p.Register(args, reply)
+	// 	*reply = p.xeth().Register(args.Hash)
 	// case "eth_unregister":
-	// 	args, err := req.ToRegisterArgs()
-	// 	if err != nil {
+	// 	args := new(HashIndexArgs)
+	// 	if err := json.Unmarshal(req.Params, &args); err != nil {
 	// 		return err
 	// 	}
-	// 	return p.Unregister(args, reply)
+	// 	*reply = p.xeth().Unregister(args.Hash)
 	// case "eth_watchTx":
-	// 	args, err := req.ToWatchTxArgs()
-	// 	if err != nil {
+	// 	args := new(HashIndexArgs)
+	// 	if err := json.Unmarshal(req.Params, &args); err != nil {
 	// 		return err
 	// 	}
-	// 	return p.WatchTx(args, reply)
+	// 	*reply = p.xeth().PullWatchTx(args.Hash)
 	default:
 		return NewNotImplementedError(req.Method)
 	}
@@ -828,14 +454,7 @@ func (p *EthereumApi) GetRequestReply(req *RpcRequest, reply *interface{}) error
 	return nil
 }
 
-func (self *EthereumApi) xeth() *xeth.XEth {
-	self.xethMu.RLock()
-	defer self.xethMu.RUnlock()
-
-	return self.eth
-}
-
-func toFilterOptions(options *FilterOptions) core.FilterOptions {
+func toFilterOptions(options *BlockFilterArgs) *core.FilterOptions {
 	var opts core.FilterOptions
 
 	// Convert optional address slice/string to byte slice
@@ -867,5 +486,13 @@ func toFilterOptions(options *FilterOptions) core.FilterOptions {
 	}
 	opts.Topics = topics
 
-	return opts
+	return &opts
 }
+
+/*
+	Work() chan<- *types.Block
+	SetWorkCh(chan<- Work)
+	Stop()
+	Start()
+	Rate() uint64
+*/
diff --git a/rpc/api_test.go b/rpc/api_test.go
index ec03822c5..727ade007 100644
--- a/rpc/api_test.go
+++ b/rpc/api_test.go
@@ -2,9 +2,9 @@ package rpc
 
 import (
 	"encoding/json"
-	"sync"
+	// "sync"
 	"testing"
-	"time"
+	// "time"
 )
 
 func TestWeb3Sha3(t *testing.T) {
@@ -24,33 +24,33 @@ func TestWeb3Sha3(t *testing.T) {
 	}
 }
 
-func TestFilterClose(t *testing.T) {
-	t.Skip()
-	api := &EthereumApi{
-		logs:     make(map[int]*logFilter),
-		messages: make(map[int]*whisperFilter),
-		quit:     make(chan struct{}),
-	}
+// func TestFilterClose(t *testing.T) {
+// 	t.Skip()
+// 	api := &EthereumApi{
+// 		logs:     make(map[int]*logFilter),
+// 		messages: make(map[int]*whisperFilter),
+// 		quit:     make(chan struct{}),
+// 	}
 
-	filterTickerTime = 1
-	api.logs[0] = &logFilter{}
-	api.messages[0] = &whisperFilter{}
-	var wg sync.WaitGroup
-	wg.Add(1)
-	go api.start()
-	go func() {
-		select {
-		case <-time.After(500 * time.Millisecond):
-			api.stop()
-			wg.Done()
-		}
-	}()
-	wg.Wait()
-	if len(api.logs) != 0 {
-		t.Error("expected logs to be empty")
-	}
+// 	filterTickerTime = 1
+// 	api.logs[0] = &logFilter{}
+// 	api.messages[0] = &whisperFilter{}
+// 	var wg sync.WaitGroup
+// 	wg.Add(1)
+// 	go api.start()
+// 	go func() {
+// 		select {
+// 		case <-time.After(500 * time.Millisecond):
+// 			api.stop()
+// 			wg.Done()
+// 		}
+// 	}()
+// 	wg.Wait()
+// 	if len(api.logs) != 0 {
+// 		t.Error("expected logs to be empty")
+// 	}
 
-	if len(api.messages) != 0 {
-		t.Error("expected messages to be empty")
-	}
-}
+// 	if len(api.messages) != 0 {
+// 		t.Error("expected messages to be empty")
+// 	}
+// }
diff --git a/rpc/args.go b/rpc/args.go
index ab1c40585..e50c9b1f5 100644
--- a/rpc/args.go
+++ b/rpc/args.go
@@ -35,8 +35,8 @@ func blockAge(raw interface{}, number *int64) (err error) {
 }
 
 type GetBlockByHashArgs struct {
-	BlockHash    string
-	Transactions bool
+	BlockHash  string
+	IncludeTxs bool
 }
 
 func (args *GetBlockByHashArgs) UnmarshalJSON(b []byte) (err error) {
@@ -57,15 +57,15 @@ func (args *GetBlockByHashArgs) UnmarshalJSON(b []byte) (err error) {
 	args.BlockHash = argstr
 
 	if len(obj) > 1 {
-		args.Transactions = obj[1].(bool)
+		args.IncludeTxs = obj[1].(bool)
 	}
 
 	return nil
 }
 
 type GetBlockByNumberArgs struct {
-	BlockNumber  int64
-	Transactions bool
+	BlockNumber int64
+	IncludeTxs  bool
 }
 
 func (args *GetBlockByNumberArgs) UnmarshalJSON(b []byte) (err error) {
@@ -86,7 +86,7 @@ func (args *GetBlockByNumberArgs) UnmarshalJSON(b []byte) (err error) {
 	}
 
 	if len(obj) > 1 {
-		args.Transactions = obj[1].(bool)
+		args.IncludeTxs = obj[1].(bool)
 	}
 
 	return nil
@@ -433,7 +433,7 @@ func (args *Sha3Args) UnmarshalJSON(b []byte) (err error) {
 	return nil
 }
 
-type FilterOptions struct {
+type BlockFilterArgs struct {
 	Earliest int64
 	Latest   int64
 	Address  interface{}
@@ -442,7 +442,7 @@ type FilterOptions struct {
 	Max      int
 }
 
-func (args *FilterOptions) UnmarshalJSON(b []byte) (err error) {
+func (args *BlockFilterArgs) UnmarshalJSON(b []byte) (err error) {
 	var obj []struct {
 		FromBlock interface{}   `json:"fromBlock"`
 		ToBlock   interface{}   `json:"toBlock"`
@@ -609,6 +609,16 @@ func (args *FilterStringArgs) UnmarshalJSON(b []byte) (err error) {
 	return nil
 }
 
+func (args *FilterStringArgs) requirements() error {
+	switch args.Word {
+	case "latest", "pending":
+		break
+	default:
+		return NewValidationError("Word", "Must be `latest` or `pending`")
+	}
+	return nil
+}
+
 type FilterIdArgs struct {
 	Id int
 }
diff --git a/rpc/args_test.go b/rpc/args_test.go
index 0d8dc4085..cfdd278b8 100644
--- a/rpc/args_test.go
+++ b/rpc/args_test.go
@@ -82,7 +82,7 @@ func TestGetBlockByHashArgs(t *testing.T) {
 	input := `["0xe670ec64341771606e55d6b4ca35a1a6b75ee3d5145a99d05921026d1527331", true]`
 	expected := new(GetBlockByHashArgs)
 	expected.BlockHash = "0xe670ec64341771606e55d6b4ca35a1a6b75ee3d5145a99d05921026d1527331"
-	expected.Transactions = true
+	expected.IncludeTxs = true
 
 	args := new(GetBlockByHashArgs)
 	if err := json.Unmarshal([]byte(input), &args); err != nil {
@@ -93,8 +93,8 @@ func TestGetBlockByHashArgs(t *testing.T) {
 		t.Errorf("BlockHash should be %v but is %v", expected.BlockHash, args.BlockHash)
 	}
 
-	if args.Transactions != expected.Transactions {
-		t.Errorf("Transactions should be %v but is %v", expected.Transactions, args.Transactions)
+	if args.IncludeTxs != expected.IncludeTxs {
+		t.Errorf("IncludeTxs should be %v but is %v", expected.IncludeTxs, args.IncludeTxs)
 	}
 }
 
@@ -112,7 +112,7 @@ func TestGetBlockByNumberArgs(t *testing.T) {
 	input := `["0x1b4", false]`
 	expected := new(GetBlockByNumberArgs)
 	expected.BlockNumber = 436
-	expected.Transactions = false
+	expected.IncludeTxs = false
 
 	args := new(GetBlockByNumberArgs)
 	if err := json.Unmarshal([]byte(input), &args); err != nil {
@@ -123,8 +123,8 @@ func TestGetBlockByNumberArgs(t *testing.T) {
 		t.Errorf("BlockHash should be %v but is %v", expected.BlockNumber, args.BlockNumber)
 	}
 
-	if args.Transactions != expected.Transactions {
-		t.Errorf("Transactions should be %v but is %v", expected.Transactions, args.Transactions)
+	if args.IncludeTxs != expected.IncludeTxs {
+		t.Errorf("IncludeTxs should be %v but is %v", expected.IncludeTxs, args.IncludeTxs)
 	}
 }
 
@@ -388,7 +388,7 @@ func TestGetDataEmptyArgs(t *testing.T) {
 	}
 }
 
-func TestFilterOptions(t *testing.T) {
+func TestBlockFilterArgs(t *testing.T) {
 	input := `[{
   "fromBlock": "0x1",
   "toBlock": "0x2",
@@ -396,7 +396,7 @@ func TestFilterOptions(t *testing.T) {
   "offset": "0x0",
   "address": "0xd5677cf67b5aa051bb40496e68ad359eb97cfbf8",
   "topics": ["0x12341234"]}]`
-	expected := new(FilterOptions)
+	expected := new(BlockFilterArgs)
 	expected.Earliest = 1
 	expected.Latest = 2
 	expected.Max = 3
@@ -404,7 +404,7 @@ func TestFilterOptions(t *testing.T) {
 	expected.Address = "0xd5677cf67b5aa051bb40496e68ad359eb97cfbf8"
 	// expected.Topics = []string{"0x12341234"}
 
-	args := new(FilterOptions)
+	args := new(BlockFilterArgs)
 	if err := json.Unmarshal([]byte(input), &args); err != nil {
 		t.Error(err)
 	}
@@ -434,16 +434,16 @@ func TestFilterOptions(t *testing.T) {
 	// }
 }
 
-func TestFilterOptionsWords(t *testing.T) {
+func TestBlockFilterArgsWords(t *testing.T) {
 	input := `[{
   "fromBlock": "latest",
   "toBlock": "pending"
   }]`
-	expected := new(FilterOptions)
+	expected := new(BlockFilterArgs)
 	expected.Earliest = 0
 	expected.Latest = -1
 
-	args := new(FilterOptions)
+	args := new(BlockFilterArgs)
 	if err := json.Unmarshal([]byte(input), &args); err != nil {
 		t.Error(err)
 	}
@@ -457,13 +457,13 @@ func TestFilterOptionsWords(t *testing.T) {
 	}
 }
 
-func TestFilterOptionsNums(t *testing.T) {
+func TestBlockFilterArgsNums(t *testing.T) {
 	input := `[{
   "fromBlock": 2,
   "toBlock": 3
   }]`
 
-	args := new(FilterOptions)
+	args := new(BlockFilterArgs)
 	err := json.Unmarshal([]byte(input), &args)
 	switch err.(type) {
 	case *DecodeParamError:
@@ -474,10 +474,10 @@ func TestFilterOptionsNums(t *testing.T) {
 
 }
 
-func TestFilterOptionsEmptyArgs(t *testing.T) {
+func TestBlockFilterArgsEmptyArgs(t *testing.T) {
 	input := `[]`
 
-	args := new(FilterOptions)
+	args := new(BlockFilterArgs)
 	err := json.Unmarshal([]byte(input), &args)
 	if err == nil {
 		t.Error("Expected error but didn't get one")
diff --git a/rpc/http.go b/rpc/http.go
index 5f2445e6c..3dfb67781 100644
--- a/rpc/http.go
+++ b/rpc/http.go
@@ -10,7 +10,7 @@ import (
 	"github.com/ethereum/go-ethereum/xeth"
 )
 
-var rpchttplogger = logger.NewLogger("RPC-HTTP")
+var rpclogger = logger.NewLogger("RPC")
 
 const (
 	jsonrpcver       = "2.0"
@@ -28,7 +28,7 @@ func JSONRPC(pipe *xeth.XEth, dataDir string) http.Handler {
 		// Limit request size to resist DoS
 		if req.ContentLength > maxSizeReqLength {
 			jsonerr := &RpcErrorObject{-32700, "Request too large"}
-			Send(w, &RpcErrorResponse{Jsonrpc: jsonrpcver, Id: nil, Error: jsonerr})
+			send(w, &RpcErrorResponse{Jsonrpc: jsonrpcver, Id: nil, Error: jsonerr})
 			return
 		}
 
@@ -37,14 +37,14 @@ func JSONRPC(pipe *xeth.XEth, dataDir string) http.Handler {
 		body, err := ioutil.ReadAll(req.Body)
 		if err != nil {
 			jsonerr := &RpcErrorObject{-32700, "Could not read request body"}
-			Send(w, &RpcErrorResponse{Jsonrpc: jsonrpcver, Id: nil, Error: jsonerr})
+			send(w, &RpcErrorResponse{Jsonrpc: jsonrpcver, Id: nil, Error: jsonerr})
 		}
 
 		// Try to parse the request as a single
 		var reqSingle RpcRequest
 		if err := json.Unmarshal(body, &reqSingle); err == nil {
 			response := RpcResponse(api, &reqSingle)
-			Send(w, &response)
+			send(w, &response)
 			return
 		}
 
@@ -57,13 +57,13 @@ func JSONRPC(pipe *xeth.XEth, dataDir string) http.Handler {
 				response := RpcResponse(api, &request)
 				resBatch[i] = response
 			}
-			Send(w, resBatch)
+			send(w, resBatch)
 			return
 		}
 
 		// Not a batch or single request, error
 		jsonerr := &RpcErrorObject{-32600, "Could not decode request"}
-		Send(w, &RpcErrorResponse{Jsonrpc: jsonrpcver, Id: nil, Error: jsonerr})
+		send(w, &RpcErrorResponse{Jsonrpc: jsonrpcver, Id: nil, Error: jsonerr})
 	})
 }
 
@@ -84,11 +84,11 @@ func RpcResponse(api *EthereumApi, request *RpcRequest) *interface{} {
 		response = &RpcErrorResponse{Jsonrpc: jsonrpcver, Id: request.Id, Error: jsonerr}
 	}
 
-	rpchttplogger.DebugDetailf("Generated response: %T %s", response, response)
+	rpclogger.DebugDetailf("Generated response: %T %s", response, response)
 	return &response
 }
 
-func Send(writer io.Writer, v interface{}) (n int, err error) {
+func send(writer io.Writer, v interface{}) (n int, err error) {
 	var payload []byte
 	payload, err = json.MarshalIndent(v, "", "\t")
 	if err != nil {
diff --git a/rpc/messages_test.go b/rpc/messages_test.go
new file mode 100644
index 000000000..5274c91e4
--- /dev/null
+++ b/rpc/messages_test.go
@@ -0,0 +1,41 @@
+package rpc
+
+import (
+	"testing"
+)
+
+func TestInsufficientParamsError(t *testing.T) {
+	err := NewInsufficientParamsError(0, 1)
+	expected := "insufficient params, want 1 have 0"
+
+	if err.Error() != expected {
+		t.Error(err.Error())
+	}
+}
+
+func TestNotImplementedError(t *testing.T) {
+	err := NewNotImplementedError("foo")
+	expected := "foo method not implemented"
+
+	if err.Error() != expected {
+		t.Error(err.Error())
+	}
+}
+
+func TestDecodeParamError(t *testing.T) {
+	err := NewDecodeParamError("foo")
+	expected := "could not decode, foo"
+
+	if err.Error() != expected {
+		t.Error(err.Error())
+	}
+}
+
+func TestValidationError(t *testing.T) {
+	err := NewValidationError("foo", "should be `bar`")
+	expected := "foo not valid, should be `bar`"
+
+	if err.Error() != expected {
+		t.Error(err.Error())
+	}
+}
diff --git a/rpc/responses.go b/rpc/responses.go
index 5e197b729..ce64f1581 100644
--- a/rpc/responses.go
+++ b/rpc/responses.go
@@ -7,6 +7,7 @@ import (
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/state"
 )
 
 type BlockRes struct {
@@ -215,3 +216,28 @@ type FilterWhisperRes struct {
 	Payload    string `json:"payload"`
 	WorkProved string `json:"workProved"`
 }
+
+type LogRes struct {
+	Address string   `json:"address"`
+	Topic   []string `json:"topic"`
+	Data    string   `json:"data"`
+	Number  uint64   `json:"number"`
+}
+
+func NewLogsRes(logs state.Logs) (ls []LogRes) {
+	ls = make([]LogRes, len(logs))
+
+	for i, log := range logs {
+		var l LogRes
+		l.Topic = make([]string, len(log.Topics()))
+		l.Address = log.Address().Hex()
+		l.Data = common.ToHex(log.Data())
+		l.Number = log.Number()
+		for j, topic := range log.Topics() {
+			l.Topic[j] = topic.Hex()
+		}
+		ls[i] = l
+	}
+
+	return
+}
diff --git a/rpc/util.go b/rpc/util.go
deleted file mode 100644
index 724c8b503..000000000
--- a/rpc/util.go
+++ /dev/null
@@ -1,86 +0,0 @@
-/*
-	This file is part of go-ethereum
-
-	go-ethereum is free software: you can redistribute it and/or modify
-	it under the terms of the GNU General Public License as published by
-	the Free Software Foundation, either version 3 of the License, or
-	(at your option) any later version.
-
-	go-ethereum is distributed in the hope that it will be useful,
-	but WITHOUT ANY WARRANTY; without even the implied warranty of
-	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-  GNU General Public License for more details.
-
-	You should have received a copy of the GNU General Public License
-	along with go-ethereum.  If not, see <http://www.gnu.org/licenses/>.
-*/
-package rpc
-
-import (
-	"time"
-
-	"github.com/ethereum/go-ethereum/common"
-	"github.com/ethereum/go-ethereum/logger"
-	"github.com/ethereum/go-ethereum/state"
-	"github.com/ethereum/go-ethereum/xeth"
-)
-
-var rpclogger = logger.NewLogger("RPC")
-
-type Log struct {
-	Address string   `json:"address"`
-	Topic   []string `json:"topic"`
-	Data    string   `json:"data"`
-	Number  uint64   `json:"number"`
-}
-
-func toLogs(logs state.Logs) (ls []Log) {
-	ls = make([]Log, len(logs))
-
-	for i, log := range logs {
-		var l Log
-		l.Topic = make([]string, len(log.Topics()))
-		l.Address = log.Address().Hex()
-		l.Data = common.ToHex(log.Data())
-		l.Number = log.Number()
-		for j, topic := range log.Topics() {
-			l.Topic[j] = topic.Hex()
-		}
-		ls[i] = l
-	}
-
-	return
-}
-
-type whisperFilter struct {
-	messages []xeth.WhisperMessage
-	timeout  time.Time
-	id       int
-}
-
-func (w *whisperFilter) add(msgs ...xeth.WhisperMessage) {
-	w.messages = append(w.messages, msgs...)
-}
-func (w *whisperFilter) get() []xeth.WhisperMessage {
-	w.timeout = time.Now()
-	tmp := w.messages
-	w.messages = nil
-	return tmp
-}
-
-type logFilter struct {
-	logs    state.Logs
-	timeout time.Time
-	id      int
-}
-
-func (l *logFilter) add(logs ...state.Log) {
-	l.logs = append(l.logs, logs...)
-}
-
-func (l *logFilter) get() state.Logs {
-	l.timeout = time.Now()
-	tmp := l.logs
-	l.logs = nil
-	return tmp
-}
diff --git a/xeth/xeth.go b/xeth/xeth.go
index 686ed4432..2c324be26 100644
--- a/xeth/xeth.go
+++ b/xeth/xeth.go
@@ -6,6 +6,8 @@ import (
 	"encoding/json"
 	"fmt"
 	"math/big"
+	"sync"
+	"time"
 
 	"github.com/ethereum/go-ethereum/accounts"
 	"github.com/ethereum/go-ethereum/common"
@@ -13,13 +15,19 @@ import (
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/event"
+	"github.com/ethereum/go-ethereum/event/filter"
 	"github.com/ethereum/go-ethereum/logger"
 	"github.com/ethereum/go-ethereum/p2p"
 	"github.com/ethereum/go-ethereum/state"
 	"github.com/ethereum/go-ethereum/whisper"
 )
 
-var pipelogger = logger.NewLogger("XETH")
+var (
+	pipelogger       = logger.NewLogger("XETH")
+	filterTickerTime = 5 * time.Minute
+	defaultGasPrice  = big.NewInt(10000000000000) //150000000000
+	defaultGas       = big.NewInt(90000)          //500000
+)
 
 // to resolve the import cycle
 type Backend interface {
@@ -62,6 +70,13 @@ type Frontend interface {
 	ConfirmTransaction(tx *types.Transaction) bool
 }
 
+// dummyFrontend is a non-interactive frontend that allows all
+// transactions but cannot not unlock any keys.
+type dummyFrontend struct{}
+
+func (dummyFrontend) UnlockAccount([]byte) bool                  { return false }
+func (dummyFrontend) ConfirmTransaction(*types.Transaction) bool { return true }
+
 type XEth struct {
 	eth            Backend
 	blockProcessor *core.BlockProcessor
@@ -71,15 +86,20 @@ type XEth struct {
 	whisper        *Whisper
 
 	frontend Frontend
+
+	quit          chan struct{}
+	filterManager *filter.FilterManager
+
+	logMut sync.RWMutex
+	logs   map[int]*logFilter
+
+	messagesMut sync.RWMutex
+	messages    map[int]*whisperFilter
+
+	// regmut   sync.Mutex
+	// register map[string][]*interface{} // TODO improve return type
 }
 
-// dummyFrontend is a non-interactive frontend that allows all
-// transactions but cannot not unlock any keys.
-type dummyFrontend struct{}
-
-func (dummyFrontend) UnlockAccount([]byte) bool                  { return false }
-func (dummyFrontend) ConfirmTransaction(*types.Transaction) bool { return true }
-
 // New creates an XEth that uses the given frontend.
 // If a nil Frontend is provided, a default frontend which
 // confirms all transactions will be used.
@@ -90,15 +110,76 @@ func New(eth Backend, frontend Frontend) *XEth {
 		chainManager:   eth.ChainManager(),
 		accountManager: eth.AccountManager(),
 		whisper:        NewWhisper(eth.Whisper()),
+		quit:           make(chan struct{}),
+		filterManager:  filter.NewFilterManager(eth.EventMux()),
 		frontend:       frontend,
+		logs:           make(map[int]*logFilter),
+		messages:       make(map[int]*whisperFilter),
 	}
 	if frontend == nil {
 		xeth.frontend = dummyFrontend{}
 	}
 	xeth.state = NewState(xeth, xeth.chainManager.TransState())
+	go xeth.start()
+	go xeth.filterManager.Start()
+
 	return xeth
 }
 
+func (self *XEth) start() {
+	timer := time.NewTicker(2 * time.Second)
+done:
+	for {
+		select {
+		case <-timer.C:
+			self.logMut.Lock()
+			self.messagesMut.Lock()
+			for id, filter := range self.logs {
+				if time.Since(filter.timeout) > filterTickerTime {
+					self.filterManager.UninstallFilter(id)
+					delete(self.logs, id)
+				}
+			}
+
+			for id, filter := range self.messages {
+				if time.Since(filter.timeout) > filterTickerTime {
+					self.Whisper().Unwatch(id)
+					delete(self.messages, id)
+				}
+			}
+			self.messagesMut.Unlock()
+			self.logMut.Unlock()
+		case <-self.quit:
+			break done
+		}
+	}
+}
+
+func (self *XEth) stop() {
+	close(self.quit)
+}
+
+func (self *XEth) DefaultGas() *big.Int      { return defaultGas }
+func (self *XEth) DefaultGasPrice() *big.Int { return defaultGasPrice }
+
+func (self *XEth) AtStateNum(num int64) *XEth {
+	chain := self.Backend().ChainManager()
+	var block *types.Block
+
+	if num < 0 {
+		num = chain.CurrentBlock().Number().Int64() + num + 1
+	}
+	block = chain.GetBlockByNumber(uint64(num))
+
+	var st *state.StateDB
+	if block != nil {
+		st = state.New(block.Root(), self.Backend().StateDb())
+	} else {
+		st = chain.State()
+	}
+	return self.WithState(st)
+}
+
 func (self *XEth) Backend() Backend { return self.eth }
 func (self *XEth) WithState(statedb *state.StateDB) *XEth {
 	xeth := &XEth{
@@ -241,6 +322,157 @@ func (self *XEth) SecretToAddress(key string) string {
 	return common.ToHex(pair.Address())
 }
 
+func (self *XEth) RegisterFilter(args *core.FilterOptions) int {
+	var id int
+	filter := core.NewFilter(self.Backend())
+	filter.SetOptions(args)
+	filter.LogsCallback = func(logs state.Logs) {
+		self.logMut.Lock()
+		defer self.logMut.Unlock()
+
+		self.logs[id].add(logs...)
+	}
+	id = self.filterManager.InstallFilter(filter)
+	self.logs[id] = &logFilter{timeout: time.Now()}
+
+	return id
+}
+
+func (self *XEth) UninstallFilter(id int) bool {
+	if _, ok := self.logs[id]; ok {
+		delete(self.logs, id)
+		self.filterManager.UninstallFilter(id)
+		return true
+	}
+
+	return false
+}
+
+func (self *XEth) NewFilterString(word string) int {
+	var id int
+	filter := core.NewFilter(self.Backend())
+
+	switch word {
+	case "pending":
+		filter.PendingCallback = func(tx *types.Transaction) {
+			self.logMut.Lock()
+			defer self.logMut.Unlock()
+
+			self.logs[id].add(&state.StateLog{})
+		}
+	case "latest":
+		filter.BlockCallback = func(block *types.Block, logs state.Logs) {
+			self.logMut.Lock()
+			defer self.logMut.Unlock()
+
+			for _, log := range logs {
+				self.logs[id].add(log)
+			}
+			self.logs[id].add(&state.StateLog{})
+		}
+	}
+
+	id = self.filterManager.InstallFilter(filter)
+	self.logs[id] = &logFilter{timeout: time.Now()}
+
+	return id
+}
+
+func (self *XEth) FilterChanged(id int) state.Logs {
+	self.logMut.Lock()
+	defer self.logMut.Unlock()
+
+	if self.logs[id] != nil {
+		return self.logs[id].get()
+	}
+
+	return nil
+}
+
+func (self *XEth) Logs(id int) state.Logs {
+	self.logMut.Lock()
+	defer self.logMut.Unlock()
+
+	filter := self.filterManager.GetFilter(id)
+	if filter != nil {
+		return filter.Find()
+	}
+
+	return nil
+}
+
+func (self *XEth) AllLogs(args *core.FilterOptions) state.Logs {
+	filter := core.NewFilter(self.Backend())
+	filter.SetOptions(args)
+
+	return filter.Find()
+}
+
+func (p *XEth) NewWhisperFilter(opts *Options) int {
+	var id int
+	opts.Fn = func(msg WhisperMessage) {
+		p.messagesMut.Lock()
+		defer p.messagesMut.Unlock()
+		p.messages[id].add(msg) // = append(p.messages[id], msg)
+	}
+	id = p.Whisper().Watch(opts)
+	p.messages[id] = &whisperFilter{timeout: time.Now()}
+	return id
+}
+
+func (p *XEth) UninstallWhisperFilter(id int) bool {
+	if _, ok := p.messages[id]; ok {
+		delete(p.messages, id)
+		return true
+	}
+
+	return false
+}
+
+func (self *XEth) MessagesChanged(id int) []WhisperMessage {
+	self.messagesMut.Lock()
+	defer self.messagesMut.Unlock()
+
+	if self.messages[id] != nil {
+		return self.messages[id].get()
+	}
+
+	return nil
+}
+
+// func (self *XEth) Register(args string) bool {
+// 	self.regmut.Lock()
+// 	defer self.regmut.Unlock()
+
+// 	if _, ok := self.register[args]; ok {
+// 		self.register[args] = nil // register with empty
+// 	}
+// 	return true
+// }
+
+// func (self *XEth) Unregister(args string) bool {
+// 	self.regmut.Lock()
+// 	defer self.regmut.Unlock()
+
+// 	if _, ok := self.register[args]; ok {
+// 		delete(self.register, args)
+// 		return true
+// 	}
+
+// 	return false
+// }
+
+// // TODO improve return type
+// func (self *XEth) PullWatchTx(args string) []*interface{} {
+// 	self.regmut.Lock()
+// 	defer self.regmut.Unlock()
+
+// 	txs := self.register[args]
+// 	self.register[args] = nil
+
+// 	return txs
+// }
+
 type KeyVal struct {
 	Key   string `json:"key"`
 	Value string `json:"value"`
@@ -298,11 +530,6 @@ func (self *XEth) PushTx(encodedTx string) (string, error) {
 	return tx.Hash().Hex(), nil
 }
 
-var (
-	defaultGasPrice = big.NewInt(10000000000000)
-	defaultGas      = big.NewInt(90000)
-)
-
 func (self *XEth) Call(fromStr, toStr, valueStr, gasStr, gasPriceStr, dataStr string) (string, error) {
 	statedb := self.State().State() //self.chainManager.TransState()
 	msg := callmsg{
@@ -333,12 +560,44 @@ func (self *XEth) Transact(fromStr, toStr, valueStr, gasStr, gasPriceStr, codeSt
 		from             = common.HexToAddress(fromStr)
 		to               = common.HexToAddress(toStr)
 		value            = common.NewValue(valueStr)
-		gas              = common.NewValue(gasStr)
-		price            = common.NewValue(gasPriceStr)
+		gas              = common.Big(gasStr)
+		price            = common.Big(gasPriceStr)
 		data             []byte
 		contractCreation bool
 	)
 
+	// TODO if no_private_key then
+	//if _, exists := p.register[args.From]; exists {
+	//	p.register[args.From] = append(p.register[args.From], args)
+	//} else {
+	/*
+		account := accounts.Get(common.FromHex(args.From))
+		if account != nil {
+			if account.Unlocked() {
+				if !unlockAccount(account) {
+					return
+				}
+			}
+
+			result, _ := account.Transact(common.FromHex(args.To), common.FromHex(args.Value), common.FromHex(args.Gas), common.FromHex(args.GasPrice), common.FromHex(args.Data))
+			if len(result) > 0 {
+				*reply = common.ToHex(result)
+			}
+		} else if _, exists := p.register[args.From]; exists {
+			p.register[ags.From] = append(p.register[args.From], args)
+		}
+	*/
+
+	// TODO: align default values to have the same type, e.g. not depend on
+	// common.Value conversions later on
+	if gas.Cmp(big.NewInt(0)) == 0 {
+		gas = defaultGas
+	}
+
+	if price.Cmp(big.NewInt(0)) == 0 {
+		price = defaultGasPrice
+	}
+
 	data = common.FromHex(codeStr)
 	if len(toStr) == 0 {
 		contractCreation = true
@@ -346,9 +605,9 @@ func (self *XEth) Transact(fromStr, toStr, valueStr, gasStr, gasPriceStr, codeSt
 
 	var tx *types.Transaction
 	if contractCreation {
-		tx = types.NewContractCreationTx(value.BigInt(), gas.BigInt(), price.BigInt(), data)
+		tx = types.NewContractCreationTx(value.BigInt(), gas, price, data)
 	} else {
-		tx = types.NewTransactionMessage(to, value.BigInt(), gas.BigInt(), price.BigInt(), data)
+		tx = types.NewTransactionMessage(to, value.BigInt(), gas, price, data)
 	}
 
 	state := self.chainManager.TxState()
@@ -407,3 +666,36 @@ func (m callmsg) GasPrice() *big.Int            { return m.gasPrice }
 func (m callmsg) Gas() *big.Int                 { return m.gas }
 func (m callmsg) Value() *big.Int               { return m.value }
 func (m callmsg) Data() []byte                  { return m.data }
+
+type whisperFilter struct {
+	messages []WhisperMessage
+	timeout  time.Time
+	id       int
+}
+
+func (w *whisperFilter) add(msgs ...WhisperMessage) {
+	w.messages = append(w.messages, msgs...)
+}
+func (w *whisperFilter) get() []WhisperMessage {
+	w.timeout = time.Now()
+	tmp := w.messages
+	w.messages = nil
+	return tmp
+}
+
+type logFilter struct {
+	logs    state.Logs
+	timeout time.Time
+	id      int
+}
+
+func (l *logFilter) add(logs ...state.Log) {
+	l.logs = append(l.logs, logs...)
+}
+
+func (l *logFilter) get() state.Logs {
+	l.timeout = time.Now()
+	tmp := l.logs
+	l.logs = nil
+	return tmp
+}