I use RedHat9 as a small office server. I have public ip, 24 hours internet connection. I use squid. The linux default firewall is disabled. In the server machine there are 2 NIC. One of the internal network, the other is for the internet connection.

I want to use voice chat by yahoo messenger.

If I try to use it with one of the network machines (which is connected to the internet through the squid) , I can connect and I can chat in a classical way (typing), but when I try to use voice chat, it says me that it is unable to use voice chat because of the firewall or proxy.

On the other hand, if I connect this computer direct to the internet (draw the utp cable out of the server and put it in this computer) I am able to use voice chat.

Can somebody tell me, how to configure the firewall and/or proxy to use voice chat, or where can I get information about it?

Thank you!

//Moderator note: you have crossposted a message, which is against the LQ Rules. Cross-posting is considered bad netiquette on your part, a waste of resources on LQ's part and a waste of time for LQ members who take the time your question.
Do not do that again.