Here we go again!


Snom 370 SIP Phone Through NAT to 3CX

My article relating to this was accepted and posted in the official 3CX blog.  You can read it here.

  • pcunite

    For point number 4 reqarding the Keepalive Interval you write:

    4. I set the STUN Interval to five minutes. I set the Keepalive Interval to 20 seconds. The Keepalive Interval needs to be shorter than the amount of time than your firewall keeps NAT translations around. You may need to play with this value. If it is too long you may not be able to receive incoming calls.

    It is more accurate to say that the Keepalive Interval keeps the UDP port from expiring and thus being closed by your router/firewall. Most routers will close an unused UDP port in 180 seconds.