3.2.2 Timers
The server MAY start a 20-second timer when it sends a MILCTRLCMD_VERSIONREQUEST message or a MILCMD_TRANSPORT_SYNCFLUSH message to the client.
The response for a MILCTRLCMD_VERSIONREQUEST message is a MILMSG_VERSIONREPLY message. If the reply does not arrive before the timer expires, the server MAY terminate the connection on the assumption that the requested version is unsupported.
The response for a MILCMD_TRANSPORT_SYNCFLUSH message is a MILMSG_SYNCFLUSHREPLY message. If the reply does not arrive before the timer expires, the server MAY stop waiting and ignore any reply that comes late.