There have been sporadic problems with the responsiveness of TPU because of a lot of GameSpy traffic being generated by a few specific IP addresses on the internet. There are a few possibilities: a) a misconfigured or misbehaving server monitor or GameSpy client; b) a DDoS attack against TPU; or c) a DDoS attack against some other site that is attempting to use the TPU server as part of the attack (GameSpy-enabled servers like TPU can be used to propagate DDoS attacks).

I'm blocking these IP addresses when I see them, but unfortunately that requires rebooting the router, so any current server connections are dropped. I will try to time the reboots to occur between maps.

Here are the offending IP addresses (note that these may be spoofed):
99.198.97.162 (server.g4tc-us-razor.com)
96.42.17.206
69.162.99.35 (a high profile game server in the US)
69.162.99.38 (a high profile game server in the US)
208.64.121.101