muwire/doc/binary-pongs.md

Upgrade to binary pongs

Motivation

The current intra-peer protocol is JSON, which means messages need to be ascii-armored. This is not as optimal as a binary protocol, especially when sending large blobs like I2P destinations.

Upgrade path

The pinging node sends pings with the version field set to 2.

Upon receiving pings with version 2, the responding node will send a binary Pong.

Pong format:

byte 0: message type, fixed at 1 for "Pong"
byte 1: version, fixed at 2
bytes 2-18: UUID of the Pong
byte 19: number of destinations contained in this Pong
bytes 20-end: destinations

Other benefits

With the reduced size of Pong messages each Pong can carry more destinations. Also, the default maximum number of connections can be increased.