Unanswerable calls

[chunter]

Hello,

We have recently been having an issue where a call will come in and cause the phone to ring but the phone locks up and cannot be answered and will just ring forever. I have found no pattern in the users this happens to but it does seem to happen to some users more than others. It also seems to be getting worse. A few months ago it was maybe one occurrence a week and it is now happening multiple times a day. The call log shows the call as an incoming call that was not answered.

We are all using Grandstream GXP 2160 phones with the currently supported firmware (1.0.9.102 I think) and users have the softphone installed as well on their workstations. We are on 3CX 15.5 which runs on a Windows VM that is located offsite. There is an IPSec tunnel connecting our office to the datacenter the VM is located in. I have run the firewall checker and had no issues there.

I am at a loss on how to troubleshoot this problem and would appreciate any nudge in the correct direction. I am also happy to provide any further information to help troubleshoot just let me know what is needed.

Here is the activity log from one of the calls that caused this.

03/20/2019 10:58:59 AM - Leg L:3969.4[Extn:12] is terminated: Cause: 487 Request Terminated/INVITE from 192.168.104.12:5060

03/20/2019 10:58:59 AM - Leg L:3969.3[Extn:12] is terminated: Cause: 487 Request Terminated/INVITE from 192.168.100.139:50420

03/20/2019 10:58:59 AM - L:3969.1[Line:10001<<3145874200] forwards call from Extn:12 to VMail:99 based on rule Fwd[Available/NoAnsw]

03/20/2019 10:58:59 AM - L:3969.1[Line:10001<<3145874200] failed to reach Extn:12, reason No Answer

03/20/2019 10:58:39 AM - [CM505001]: Endpoint Extn:12: Device info: Device Not Identified: User Agent not matched; Capabilities:[reinvite, replaces, able-no-sdp, recvonly] UserAgent: [3CXPhone for Windows 15.5.12227.5] PBX contact: [sip:[email protected]:5060]

03/20/2019 10:58:39 AM - [CM503002]: Call(C:3969): Alerting Extn:12 by contact <sip:[email protected]:50420>

03/20/2019 10:58:39 AM - [CM505001]: Endpoint Extn:12: Device info: Device Not Identified: User Agent not matched; Capabilities:[reinvite, replaces, able-no-sdp, recvonly] UserAgent: [Grandstream GXP2160 1.0.9.102 000b8273d503] PBX contact: [sip:[email protected]:5060]

03/20/2019 10:58:39 AM - [CM503002]: Call(C:3969): Alerting Extn:12 by contact <sip:[email protected]:5060>

03/20/2019 10:58:39 AM - [CM503025]: Call(C:3969): Calling T:Extn:12@[Dev:sip:[email protected]:50420;rinstance=0-d8b755fbf4b04c6a982f3066a5e51c7f;ob,Dev:sip:[email protected]:5060] for L:3969.1[Line:10001<<3145874200]

03/20/2019 10:58:39 AM - [CM503025]: Call(C:3969): Calling T:Extn:12@[Dev:sip:[email protected]:50420;rinstance=0-d8b755fbf4b04c6a982f3066a5e51c7f;ob,Dev:sip:[email protected]:5060] for L:3969.1[Line:10001<<3145874200]

03/20/2019 10:58:38 AM - [CM503027]: Call(C:3969): From: Line:10001<<3145874200 ("IWTLocal:ENTERPRISE RENT" <sip:[email protected]:5060>) to T:Extn:12@[Dev:sip:[email protected]:50420;rinstance=0-d8b755fbf4b04c6a982f3066a5e51c7f;ob,Dev:sip:[email protected]:5060]

03/20/2019 10:58:38 AM - [CM503004]: Call(C:3969): Route 1: from L:3969.1[Line:10001<<3145874200] to T:Extn:12@[Dev:sip:[email protected]:50420;rinstance=0-d8b755fbf4b04c6a982f3066a5e51c7f;ob,Dev:sip:[email protected]:5060]

03/20/2019 10:58:38 AM - [Flow] Call(C:3969): has built target endpoint: Extn:12 for call from L:3969.1[Line:10001<<3145874200]

03/20/2019 10:58:38 AM - [Flow] Target endpoint for 12 is Extn:12

 

[JohnS_3CX]

Hi @chunter

1. Does the problem appear only on the GXP? Can they answer the call correctly on the softphone?

2. What is the exact behavior of the GXP phone? You see ringing alert on the screen, pick up the handset and nothing changes on the screen? Give us some more detail if you can, and test to see if you can answer in speakerphone mode too as opposed to handset. Eliminate the chance of a hardware error or headset related error

 

[chunter]

Hi John,

Thanks for the response!

Yes the issue only appears on the GXP. The user can answer on the softphone and the physical phone will continue ringing until power is removed. I actually had this happen yesterday where a user was working from home and answered a call on her laptop while at home and her desk phone continued ringing for several minutes until someone unplugged it.

You cannot answer on speaker phone or do anything else for that matter on the GXP phone. It is completely frozen and stuck in a ringing state. No menus or buttons function. Basically, a call comes in and shows it's source on the caller ID, the user then tries to either pick up the handset or answer via a Bluetooth headset and the phone is simply frozen.

I can, however, access the phone's web UI and that is functional when it is stuck in the ringing state.



My first thought was defective phones so I actually replaced two of the phones for the two users it happens most often to and the issue persists. The problem seems to be random though. It has hit 9 of the 23 physical phones we have so far with a new one added yesterday.

Please let me know if you need any more information.

Thanks!

 

[JohnS_3CX]

Just a clarification, are you auto provisioning as a LAN device with the default 3CX templates?

Also are they all on the same switch? Powered by PoE or AC adapter?

 

[chunter]

Yes they are auto-provisioned as a LAN device with the default 3CX template.

All are powered by AC adapter.

They do not all share the same switch.

 

[JohnS_3CX]

This an unusual case where the interface/buttons/ringing freezes but clearly not the whole phone since you have web UI access. You would need a way to debug the phone itself to find out why this happens.

I suggest raising a case with GrandStream on this one and see what they make of it.

 

[chunter]

Thanks for the advice. I will see what information I can gather from the phone vendor.