diff --git a/doc/reducetraffic.md b/doc/reducetraffic.md new file mode 100644 index 000000000..085da1a28 --- /dev/null +++ b/doc/reducetraffic.md @@ -0,0 +1,36 @@ +REDUCE TRAFFIC +============== + +Some node operators need to deal with bandwith cap given by their ISPs. + +By default, bitcoin-core allows up to 125 connections to different peers, 8 of +them outbound (and therefore 117 max inbound connections). + +The default settings can result in relatively significant traffic consumption. + + +Ways to reduce traffic: + +1. Use `-maxuploadtarget=` + +A major part of the traffic is caused by serving historic blocks to other nodes +in initial blocks download state (syncing up a new node). +This option can be specified in MiB per day and is turned off by default. +This is *not* a hard limit but a threshold to minimize the outbound +traffic. When the limit is about to be reached, the uploaded data is cut by not +serving historic blocks (blocks older than one week). +Keep in mind that new nodes require other nodes that are willing to serve +historic blocks. **The recommended minimum is 144 blocks per day (max. 144MB +per day)** + +2. Disable "listening" (`-listen=0`) + +Disable listening will result in fewer nodes connected (remind the max of 8 +outbound peers). Fewer nodes will result in less traffic usage because relaying +blocks and transaction needs to be passed to fewer nodes. + +3. Reduce maximal connections (`-maxconnections=`) + +Reducing the connected nodes to a miniumum can be desired in case traffic +limits are tiny. Keep in mind that bitcoin trustless model works best if you are +connected to a handfull of nodes.