| BEP: | 4 |
|---|---|
| Title: | Assigned Numbers |
| Version: | 48dfdcb0b1c4c6bbc8eea0b76a81ade0ef5a5f9a |
| Last-Modified: | Sun Mar 26 01:08:47 2017 +0100 |
| Author: | David Harrison <dave@bittorrent.com> |
| Status: | Active |
| Type: | Process |
| Created: | 10-Jan-2008 |
| Post-History: |
This document describes the known bit allocations and message IDs for the BitTorrent protocol. To request a bit allocation contact editor@bittorrent.org. Contact the same address if you are aware of any omissions.
reserved[0] 0x80 Azureus Messaging Protocol reserved[2] 0x08 BitTorrent Location-aware Protocol (no known implementations) reserved[5] 0x10 LTEP (Libtorrent Extension Protocol) 0x02 Extension Negotiation Protocol 0x01 Extension Negotiation Protocol reserved[7] 0x01 BitTorrent DHT 0x02 XBT Peer Exchange 0x04 suggest, haveall, havenone, reject request, and allow fast extensions 0x08 NAT Traversal 0x10 hybrid torrent legacy to v2 upgrade
There are known collisions:
reserved[0] 0xFF BitComet Extension Protocol reserved[1] 0xFF BitComet Extension Protocol reserved[7] 0x01 XBT Metadata Exchange (implemented only in XBT)
It is recommended that further extensions use the Extension Protocol [1], a.k.a., LibTorrent Extension Protocol (LTEP). With LTEP, extension bit collisions become impossible since no new extension bits are allocated. With LTEP, message ID collisions also become impossible because message IDs are allocated on demand at the beginning of the connection. Extension name collisions become possible, but the probability is much less likely.
Core Protocol: 0x00 choke 0x01 unchoke 0x02 interested 0x03 not interested 0x04 have 0x05 bitfield 0x06 request 0x07 piece 0x08 cancel DHT Extension: 0x09 port Fast Extensions: 0x0D suggest 0x0E have all 0x0F have none 0x10 reject request 0x11 allowed fast Additional IDs used in deployed clients: 0x14 LTEP Handshake (implemented in libtorrent, uTorrent,...) Hash Transfer Protocol: 0x15 hash request 0x16 hashes 0x17 hash reject
| [1] | BEP_0010. Extension Protocol. Norberg, Strigeus, Hazel. http://www.bittorrent.org/beps/bep_0010.html |
This document has been placed in the public domain.