mirror of https://github.com/zcash/zips.git
220 lines
8.2 KiB
ReStructuredText
220 lines
8.2 KiB
ReStructuredText
::
|
|
|
|
ZIP: 252
|
|
Title: Deployment of the NU5 Network Upgrade
|
|
Owners: teor <teor@zfnd.org>
|
|
Daira Hopwood <daira@electriccoin.co>
|
|
Status: Proposed
|
|
Category: Consensus / Network
|
|
Created: 2021-02-23
|
|
License: MIT
|
|
Discussions-To: <https://github.com/zcash/zips/issues/440>
|
|
Pull-Request: <https://github.com/zcash/zips/pull/446>
|
|
|
|
|
|
Terminology
|
|
===========
|
|
|
|
The key words "MUST" and "SHOULD" in this document are to be interpreted as
|
|
described in RFC 2119. [#RFC2119]_
|
|
|
|
The term "network upgrade" in this document is to be interpreted as described in
|
|
ZIP 200. [#zip-0200]_
|
|
|
|
The terms "Testnet" and "Mainnet" are to be interpreted as described in
|
|
section 3.11 of the Zcash Protocol Specification [#protocol-networks]_.
|
|
|
|
|
|
Abstract
|
|
========
|
|
|
|
This proposal defines the deployment of the NU5 network upgrade.
|
|
|
|
|
|
Specification
|
|
=============
|
|
|
|
NU5 deployment
|
|
--------------
|
|
|
|
The primary sources of information about NU5 consensus and peer-to-peer protocol
|
|
changes are:
|
|
|
|
- The Zcash Protocol Specification [#protocol]_
|
|
- ZIP 200: Network Upgrade Mechanism [#zip-0200]_
|
|
- ZIP 216: Require Canonical Point Encodings [#zip-0216]_
|
|
- ZIP 221: FlyClient - Consensus-Layer Changes [#zip-0221]_ (amended)
|
|
- ZIP 224: Orchard Shielded Protocol [#zip-0224]_
|
|
- ZIP 225: Version 5 Transaction Format [#zip-0225]_
|
|
- ZIP 239: Relay of Version 5 Transactions [#zip-0239]_
|
|
- ZIP 244: Transaction Identifier Non-Malleability [#zip-0244]_
|
|
- The Orchard Book [#orchard-book]_
|
|
- The halo2 Book [#halo2-book]_
|
|
|
|
The network handshake and peer management mechanisms defined in ZIP 201 [#zip-0201]_
|
|
also apply to this upgrade. Unified addresses and viewing keys are described in
|
|
ZIP 316 [#zip-0316]_. ZIP 32 [#zip-0032]_ has been amended to include hierarchical
|
|
key derivation for Orchard.
|
|
|
|
Support for the ``addrv2`` peer protocol message, defined in ZIP 155 [#zip-0155],
|
|
is being added concurrently with this upgrade, signalled by the same Mainnet peer
|
|
protocol version.
|
|
|
|
|
|
The following network upgrade constants [#zip-0200]_ are defined for the NU5
|
|
upgrade:
|
|
|
|
CONSENSUS_BRANCH_ID
|
|
``0xF919A198``
|
|
|
|
|
|
ACTIVATION_HEIGHT (NU5)
|
|
Testnet: TODO
|
|
|
|
Mainnet: TODO
|
|
|
|
|
|
MIN_NETWORK_PROTOCOL_VERSION (NU5)
|
|
Testnet: 170014
|
|
|
|
Mainnet: 170015
|
|
|
|
|
|
For each network (Testnet and Mainnet), nodes compatible with NU5 activation
|
|
on that network MUST advertise a network protocol version that is greater than
|
|
or equal to that network's MIN_NETWORK_PROTOCOL_VERSION (NU5).
|
|
|
|
For each network, pre-NU5 nodes are defined as nodes advertising a protocol
|
|
version less than that network's MIN_NETWORK_PROTOCOL_VERSION (NU5).
|
|
|
|
Once NU5 activates on Testnet or Mainnet, NU5 nodes SHOULD take steps to:
|
|
|
|
- reject new connections from pre-NU5 nodes on that network;
|
|
- disconnect any existing connections to pre-NU5 nodes on that network.
|
|
|
|
The change to the peer-to-peer protocol described in ZIP 239 takes effect
|
|
from peer protocol version 170014 onward, on both Testnet and Mainnet. [#zip-0239]_
|
|
|
|
The change to the peer-to-peer protocol described in ZIP 155 takes effect
|
|
from peer protocol version 170015 onward, on both Testnet and Mainnet. [#zip-0155]_
|
|
|
|
Note: these peer-to-peer protocol changes are enabled whenever the relevant
|
|
version (or higher) is negotiated on a given connection, which can happen in
|
|
advance of the Testnet or Mainnet NU5 activation.
|
|
|
|
|
|
Backward compatibility
|
|
======================
|
|
|
|
Prior to the network upgrade activating on each network, NU5 and pre-NU5
|
|
nodes are compatible and can connect to each other.
|
|
|
|
Once the network upgrades, even though pre-NU5 nodes can still accept the
|
|
numerically larger protocol version used by NU5 as being valid, NU5 nodes
|
|
will always disconnect peers using lower protocol versions.
|
|
|
|
Unlike Blossom, Heartwood, and Canopy, and like Overwinter and Sapling, NU5
|
|
defines a new transaction version. Therefore, NU5 transactions MAY be in
|
|
the new v5 format specified by [#zip-0225]_. Unlike previous transaction
|
|
version updates, the existing v4 transaction format remains valid after
|
|
NU5 activation. Both transaction formats MUST be accepted by NU5 nodes.
|
|
|
|
Backward compatibility of the new ``MSG_WTX`` inv type introduced for ``inv``
|
|
and ``getdata`` messages is discussed in [#zip-0239]_.
|
|
|
|
Backward compatibility of the new ``addrv2`` message (not technically part of
|
|
NU5) is discussed in [#zip-0155]_.
|
|
|
|
|
|
Support in zcashd
|
|
=================
|
|
|
|
**TODO: Update as needed**
|
|
|
|
Support for NU5 on Testnet will be implemented in ``zcashd`` version 4.5.0, which
|
|
will advertise protocol version 170014. Support for NU5 on Mainnet will be implemented
|
|
in ``zcashd`` version 5.0.0, which will advertise protocol version 170015.
|
|
|
|
|
|
Backward compatibility in zcashd
|
|
--------------------------------
|
|
|
|
The minimum peer protocol version that NU5-compatible ``zcashd`` nodes will connect to
|
|
is 170002.
|
|
|
|
|
|
NU5 deployment for zcashd
|
|
-------------------------
|
|
|
|
For each network, approximately 1.5 days (defined in terms of
|
|
block height) before the corresponding NU5 activation height, nodes compatible
|
|
with NU5 activation on that network will change the behaviour of their peer
|
|
connection logic in order to prefer pre-NU5 peers on that network for eviction
|
|
from the set of peer connections::
|
|
|
|
/**
|
|
* The period before a network upgrade activates, where connections to upgrading peers are preferred (in blocks).
|
|
* This was three days for upgrades up to and including Blossom, and is 1.5 days from Heartwood onward.
|
|
*/
|
|
static const int NETWORK_UPGRADE_PEER_PREFERENCE_BLOCK_PERIOD = 1728;
|
|
|
|
The implementation is similar to that for Overwinter which was described in
|
|
[#zip-0201]_.
|
|
|
|
However, NU5 nodes will have a preference for connecting to other NU5 nodes, so
|
|
pre-NU5 nodes will gradually be disconnected in the run up to activation.
|
|
|
|
Support in Zebra
|
|
================
|
|
|
|
**TODO: Update as needed**
|
|
|
|
Support for NU5 on Testnet will be implemented in Zebra version 1.0.0, which
|
|
will advertise protocol version 170014. Support for NU5 on Mainnet will be implemented
|
|
in Zebra version 2.0.0, which will advertise protocol version 170015.
|
|
|
|
|
|
Backward compatibility in Zebra
|
|
-------------------------------
|
|
|
|
The minimum peer protocol version that NU5-compatible Zebra nodes will connect to
|
|
is 170002. However, Zebra will immediately disconnect from nodes with a protocol
|
|
version less than:
|
|
|
|
- 170012 on Testnet, or
|
|
- 170013 on Mainnet.
|
|
|
|
NU5 deployment for Zebra
|
|
------------------------
|
|
|
|
For each network, at the corresponding NU5 activation height, nodes compatible
|
|
with NU5 activation on that network will close any new connections with pre-NU5
|
|
peers.
|
|
|
|
Since Zebra maintains a reasonably strict internal request-response protocol,
|
|
pre-NU5 nodes will gradually be disconnected after activation. (Nodes are
|
|
temporarily disconnected if they send gossip or chain sync hints outside the
|
|
strict request-response sequence that Zebra expects.)
|
|
|
|
|
|
References
|
|
==========
|
|
|
|
.. [#RFC2119] `RFC 2119: Key words for use in RFCs to Indicate Requirement Levels <https://www.rfc-editor.org/rfc/rfc2119.html>`_
|
|
.. [#protocol] `Zcash Protocol Specification, Version 2021.1.24 or later <protocol/nu5.pdf>`_
|
|
.. [#protocol-networks] `Zcash Protocol Specification, Version 2021.1.24 [NU5 proposal]. Section 3.11: Mainnet and Testnet <protocol/nu5.pdf#networks>`_
|
|
.. [#protocol-txnencodingandconsensus] `Zcash Protocol Specification, Version 2021.1.24 [NU5 proposal]. Section 7.1: Transaction Encoding and Consensus <protocol/nu5.pdf#txnencodingandconsensus>`_
|
|
.. [#zip-0032] `ZIP 32: Shielded Hierarchical Deterministic Wallets <zip-0032.rst>`_
|
|
.. [#zip-0155] `ZIP 155: addrv2 message <zip-0155.rst>`_
|
|
.. [#zip-0200] `ZIP 200: Network Upgrade Mechanism <zip-0200.rst>`_
|
|
.. [#zip-0201] `ZIP 201: Network Peer Management for Overwinter <zip-0201.rst>`_
|
|
.. [#zip-0216] `ZIP 216: Require Canonical Point Encodings <zip-0216.rst>`_
|
|
.. [#zip-0221] `ZIP 221: FlyClient - Consensus-Layer Changes <zip-0221.rst>`_
|
|
.. [#zip-0224] `ZIP 224: Orchard Shielded Protocol <zip-0224.rst>`_
|
|
.. [#zip-0225] `ZIP 225: Version 5 Transaction Format <zip-0225.rst>`_
|
|
.. [#zip-0239] `ZIP 239: Relay of Version 5 Transactions <zip-0239.rst>`_
|
|
.. [#zip-0244] `ZIP 244: Transaction Identifier Non-Malleability <zip-0244.rst>`_
|
|
.. [#zip-0316] `ZIP 316: Unified Addresses and Unified Viewing Keys <zip-0316.rst>`_
|
|
.. [#orchard-book] `The Orchard Book <https://zcash.github.io/orchard/>`_
|
|
.. [#halo2-book] `The halo2 Book <https://zcash.github.io/halo2/>`_
|