Can not hear each other from SIP call

Hello, friends:
I have a problem in making calls by using tow SIP phones. actually the two phones are located in two different asterisk box. the regiester and peers all ok. but making a call, the other side was ringing, but no voice. I do not have firewall between the asertisks.
Does anyone has a idea for that probelm?
thanks
zhu8080

this is a common problem regarding NAT.

Make sure the two * boxes are correctly set up with their NATs, using externip= and localnet= if needed. Then set canreinvite=no in sip.conf. also make sure your rtp port range is forwarded to * and no firewalls are blocking. that should help :smile:

Hello, friend:
thank you so much. eventually it works. the asterisk A has a parameter for localnet. but that side, which is tribox with no localnet setting. it cause the problem.
thanks!
zhu8080

ah. trixbox has a localnet setting you just have to manually go into sip.conf and set it. glad it worked!