Kind of pointless, but:
In UnrealTournament.ini, find [IpDrv.TcpNetDriver]
- Change KeepAliveTime=0.0009 from KeepAliveTime=0.2
KeepAliveTime means "Send a packet if there hasn't been a packet to be sent in this many seconds". The packet thats sent does not contain any data.
One side effect of doing this is that it makes your ping look lower in the scoreboard, for me with >=41 ping(F6) it's displaying at ~ 15(f1)