I have installed dozens of the Grandstream gxp2020 without any issues. I have 1 client with 10 of these phones and some of them stops ringing for no apparent reason. I reboot the phone and it works fine for a while.
The settings match all my other accounts which have no issues. They also have hight speed FIOS internet so it is not a bandwidth problem.
It is as if the DND button is pressed which is not the case and it shows online on the phone.
Any ideas?
It was. I was looking at all
It was. I was looking at all the traces and trying to determine the cause. It seems that the router was changing all the ports going out and some how they were getting screwed up coming back causing the weird behavior.
I thought it was a server issue and was looking in the wrong place. The customers network was the culprit.
I set the phones to NAT Traversal = Yes and the problem went away. It seems that certain routers have this issue when there are more than a few phones. I have another account with the same phones but a different router and no issues.
use a sip proxy on the LAN
use a sip proxy on the LAN and there is no longer any NAT involved in the signaling path.
Sounds like a router NAT issue.