I am trying to set up an IP phone behind a PIX 501 with a site-to-site IPSEC tunnel to my corporate office. The tunnel is up and working, and I can pass traffic both ways successfully. However, when I plugged in the IP phone, I was able to get it registered, but when I make or receive a call, I don't hear anything. I can see the call progress on the screen and the other side can hear me fine, I just cannot hear them. I have tried this to multiple phones at the corporate office, as well as voicemail and PSTN, and get the same result.
I had read in the forums that I need to make sure the correct UDP ports are allowed through my PIX, but I was under the impression that a VPN tunnel passed all traffic that matched source and destination, so I didn't need to worry about additional access lists. I even went so far as to add access lists specifically permitting UDP any any between the corporate office and the local IP phone, but still no change.
I know lots of you are running IP phones behind PIX 501s, so how are you doing it?