Outgoing calls drop after 15 min 23 sec on Grandstream 1625


Hi, I’m worry about what can I do to prevent my Grandstream 1625 IP phone to drop every call after 15 min 23 sec. Same test done with different SIP providers, it happens the same (so it depends on the phone). Same test done with a different IP phone, from the same internet access, and all works perfectly (no call drops). So again, there’s something wrong with the Grandstream device. Any help?


Best is ticket to GS portal. If you want community help we would need syslog with sip packets to see who end it and maybe why (GS will request same anyway at least).


Unfortunately I’ve sign up at the Helpdesk, but when trying to login it doesn’t work either.


I can only suggest that you try and do a network capture and see which device is issuing the “BYE”. 15 min will be a rather ling capture, but it will show who or what device ended the call. Given the description, it almost seems that it would be some form of a programmatic setting in either the phone or PBX to limit the call to ~900 seconds. I suppose it could be a session timer, a max call timer, or other, but it does seem odd that the call ends at a more or less precise time.
You might also factory reset the phone, insure that its firmware is up to date and then manually re-provision and test again.


Thanks for your reply lpneblett
I’ve already tried the factory reset and the problem persists. The weird thing is that I’ve tried all this below and that’s why I concluded it depends on the GS phone:

  • calling using different device (tiptel IP280) using the same SIP account it works. Same network, even same RJ45 connection.
  • calling using the same SIP account connected to Zoiper from PC, it works.
  • calling from GS phone and using 3 different SIP accounts: it fails with the three of them

I’ve looked into all configuration parameters and didn’t came across anyone who limits the call duration.
Any other hints?


Without log it will be long battle syslog or capture is big help as bye often have reason for clearance.


Occurs on both inbound and outbound calls?

  • correctly activated keep alive at 15 seconds?
  • activate / deactivate the stun correctly? (obviously make sure you enter a working stun)
  • tried to change the listening sip port (example 5066)?
  • done correctly the nat of the RTP ports and the SIP port (example 5066)?
  • Does the router / firewall correctly support the Sip protocol? (many computer respond “yes”
    then discover that they do not even know what you’re talking about disabled the SIP ALG
  • updated the fw of the gxp? after updating it, you also make a factory reset

As someone has already suggested, you need the .pcap to analyze the problem.



I have exactly the same problem. When someone calls from his landline to any account of my GXP1628 (same problem with the last beta installed), sometimes (20% ?) it hangs down after exactly 15:00 or 30:00 minutes.


If they are phones under warranty you can open a ticket and report it. The original post talks about conversations that fall, you talk about phones that block. Quite different.


What are the devices connected to?


I’m talking about conversations that fall too. Perhaps my English is not so good, but my problem is exactly the same. Someone calls from his landline phone to my GXP1628 phone, whatever the line called (I have 2 active) and sometimes, after exactly 15:00 or 30:00 minutes, the conversation ends, like if there was as automatic hang up after a 15 minutes delay. It’s not an line configuration problem, because it’s exactly the same problem whatever the provider.


does the provider require session timers? is the phone setup to support same?