8 Ping

Behaviour in TCP-Bancho

The ping packet is used as a "healthcheck" for the client, to see if its still alive. At the same time, the client uses it to check if the server is alive as well, and will automatically close the connection.

The packet itself doesn't contain any data.

Behaviour in HTTP-Bancho

The ping packet in HTTP-Bancho is pretty much useless, unless you want the client to spam more requests to the server.