I know this is not exactly a programming question but programmers know about routing so this is a good source to get answers to my problem.
I am running a ventrilo server in my home network in Linux PC. It uses port 3784 and I have port forwarded port 3784 in my router (DIR-655) to that computer. Then, I have also a Vista PC which is connected to the same router, and which connects to the ventrilo server as a client (and others connect it too from Internet). The problem is that somehow after a while the router cannot deliver Vista PC's messages to other clients anymore in a resonable time.. Ping times start to be multiple minutes (!) making it totally unusable. It also keeps disconnecting from the ventrilo server. Other clients from Internet do not have any kind of problems (except that they hear the messages sent from Vista PC in multiple minute delay). The Vista PC is able to receive other's messages without any delay.
So, somehow my router gets messed up with the LAN connection. I have tried to set QoS to max priority for port 3784 but it did not help. I tried to put the Vista PC in DMZ but it did not help.. Basically I am clueless now. The router can be configured quite nicely so maybe there is still something I can try?
With my previous router (WRT54G) there were no such problems so this must be related to the router somehow.