Hello everyone,
I’m currently facing an issue with Polycom SoundPoint IP 335 and Polycom SoundPoint IP 650 phones on our FreePBX system.
Here’s the situation:
When we first add an extension to a phone, everything works fine: the phone can make and receive calls without any problems.
However, after a few hours (sometimes longer), the phone stops receiving incoming calls. It can still make outgoing calls, but it appears to no longer be reachable for inbound calls.
This issue happens consistently across multiple devices. The phones register correctly at first, but it seems like they “drop off” or become partially unregistered after some time.
Has anyone experienced this issue with these phone models or with FreePBX in general?
Any suggestions on what we should check?
Thank you
Whenever something like this comes to mind, my first thought is that the networking path between the telephone and the underlying Asterisk has been interrupted.
If the path between the IP phones and FreePBX has a NAT router between the equipment, like phones at a home going through a home router across the Internet to a FreePBX somewhere, and those phones are using UDP transport (which, as the default, is most likely), then the router’s going to recycle ports and close out lightly used connections. What’s happening, is that when the device registers through to Asterisk in FreePBX, Asterisk has an IP+port combination that it learns is the path back to the phone. Periodically, NAT routers will close inactive ports, and when this happens, your Asterisk server can’t reach back to the phone / can’t send it calls.
Mitigation for this is SIP keep-alives - either SIP OPTIONS, CRLF, or very frequent (30 seconds) SIP re-registration - all to keep the routed NAT port mapping alive/open.
Moving to TCP for SIP, in lieu of UDP, is usually a better solution.
This may not be your problem at all, but given your description, is the first thing I’d consider.
Good luck, I hope you end up on the right path, this may or may not be it. I probably won’t have any follow-up comments.
Thank you very much for your detailed reply!
I’m not sure yet if this will fully solve the issue, but your explanation makes a lot of sense. I really appreciate the time you took to write it.
I’ll definitely try your suggestions and see how the phones behave after that.
Thanks again for pointing me in the right direction!
This topic was automatically closed 7 days after the last reply. New replies are no longer allowed.