can not get external extension phone working

[raman07407]

My configuration is as follow
Cablevision as my ISP-->Cisco 831 Router/firewall -->winxp PC with 3cx PBX Software(No soft firewall).
Internetcalls as sip outgoing carrier.
officedigit as my incoming carrier.
x-lite softphones
I can send and receives a call fine.
My problem is that i can not hear audio in both direction when i call from one extension behind firewall to another extension outside of firewall(Cisco 831 Router) means at remote location.I can make ext to ext call fine if they are behind the firewall. same thing is also true. if i call landline number from External ext.
Any suggestion will be appreciated.I have opended all the ports which have been mentioned in the 3cx configuration guide.

 

[Mirzab]

This thread has been my Bible for ports http://www.3cx.com/forums/the-portforwarding-faq-hope-this-gets-a-sticky-1697.html and has helped to solve the majority of basic issues in my humble opinion.

List of default ports used by the 3cx phone system:
5060 (stanard sip port) TCP/UDP
5061 (secondary sip port) TCP/UDP
5480 (portgre) (only on local machine)
5481 (apache) (only on local machine)
5482 (media server) (only on local machine)
3478 (STUN Server) TCP/UDP
7000-7500 (Default port for internal calls) (only on local machine)
9000 - 9003 (ports for external calls through VOIP Gateway) UDP
10000-20000 (RTP ports) (Used if no stun available for audio)

The ports above NOT identified "only on local machine" are setup in my router as described with "Extension is External" and "Bind to Media Server" checked in Extension configuration. Works like a charm for me. Another key item is to ensure that 3CX and your external extension both use the same STUN Server. Once these points are covered there should be no reason for it not to work. That being said, stranger things have happened :cry: