unable to run voice chat through squid.

[omerfarooq]

I am using squid proxy server in my office for internet browsing.On client side they are working on windows enviroment.Everything is Ok except voice chat. yahoo messenger/ msn messenger is our chat software in Proxy client PC. I can chat in text. but when I go for voice chat it says I am behind firewall or it will hang the script. How do I enable in squid proxy server to make voice chat in client Pc?  can any one help me in this matter. omer farooq --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.410 / Virus Database: 231 - Release Date: 10/31/02