3.2.1.1.6.1 ConnectionTimeout
Network agents handling HTTP traffic often time out connections that are perceived as idle. An implementation of this protocol SHOULD try to prevent virtual connections that are still in use from being timed out by network agents handling the HTTP traffic. If network agents do time out connections perceived as idle, clients, inbound proxies, and outbound proxies MUST maintain an abstract variable, which is the amount of time that the network agents handling the HTTP traffic are likely to allow an RPC over HTTP channel to remain open and idle. That abstract variable is called ConnectionTimeout. ConnectionTimeout can range in value from 30 seconds to 1800 seconds.
Implementations of this protocol prevent IN channels and OUT channels that are in use from being timed out by network agents by sending small packets between the client and the inbound proxy and between the outbound proxy and the client. Details on this process are provided in the sections for the client (section 3.2.2) or for the outbound proxy (section 3.2.4), respectively.