Grandstream GXP2000 looses from PBX

I’ve a Grandstream GXP-2000 phone, after a certain time it looses registration from Asterisk FreePbx, but it still ring and when I answer I hear nothing.
I’ve another Grandstream model and another Voip phone that work well.
What could be the problem?
What log I’ve to check for analyzing the problem? There are a lot of logs and lines in each log.

did you figure out what was the cause of this? I’m having the same problem

On the same LAN segment, or remote? Current firmware on the Grandstream (they had some REALLY buggy ones for the 2000)? Other phones that are working in the same location or different?

If you’re using a power supply and not POE, replace the power supply.


Mine GXP2000 work very good with FreePBX 2.11 Asterisk 10.4. I did update the firmware on the GXP2000 to whatever the latest is available. I also had to edit RTP ports as the range of the default ports was not in range of what is in freepbx.

In FreePBX, go to “Settings” -> “Advanced Settings” find “Sip and IAX qualify” and change to “no”. Also check in “Extensions” for your extension that SIP Qualify is set to “no”.

Thanks for the comments. I updated the firmware of the phones to the latest and everything looks good so far.

There is one thing weird that is happening. Once a day a random non-existent extension rings all the phones at once all lines. Any thoughts on that?

Look at CDR records in “Reports”->“CDR Reports”, run a search for the time/date when the “random” event took place. It is possible that you are being probed, if your FreePBX is available to extensions from outside.

You can also disable “Allow Guests” and “Allow Anonymous SIP Calls” settings under “Settings”->“Asterisk SIP Settings”. Although I do not know what those there for, but disabling them does not have any negative effect in our office system.

This is happening more often now. I’ve tried disabling “Allow Anonymous SIP Calls” but then incoming calls get rejected. Here’s what I can see in the logs

WARNING[3408]: Ext. s:6 @ from-sip-external: “Rejecting unknown SIP connection from”

Not sure what to look in the CDR report. Here’s a sample of one of the calls