[Asterisk-Users] PIX Firewall configuration??

[infoman at colonydrive.com]

I'd like to open up my firwall so that I can connect my SIP phones to a
test server behind or firewall. I can configure an outside addtess to pass
traffic to the internal address of the Asterisk server. I'm not sure what
other ports need to be opened. My SIP phone will either be at my home
behind a linksys cable/dsl router or perhaps at a hotel when I'm on the
road. What am I missing in this configuration? Is STUN needed?

Pat