Polycom VVX 601 reboots after receiving NOTIFY from 3cx

[George Ts]

Hello,
For the past two days my Polycom VVX 601 has been rebooting for no apparent reason.
I have not been able to spot the pattern, but I noticed that this happens right after the Polycom receives a SIP NOTIFY from the 3cx, to which the Polycom responds with 403. The NOTIFY request has an event of "message-summary".

Please note that my Polycom has its parameter "reg.1.lineKeys=2", which means that my own number is displayed in the Polycom's screen and SUBSCRIBED twice , as seen in the attached image.
"John" is another extension monitored by me own ext. 6240 via BLF (configured BLF in 3cx and automatically provisioned my Polycom accordingly).

Now, I see that during "normal" operation, 3cx does not send NOTIFY requests to my Polycom. In fact, I can see the 3cx sending NOTIFY requests right after the Polycom's reboot. Once those are responded with 200OK by the Polycom, everything is fine. (see attached trace and kindly notice timestamps, as after the reboot NOTIFY's are responded with 200OK)

3cx = 192.168.103.12
Polycom = 192.168.81.107

From the attached trace:
A. The first two underlined 403 responses are to NOTIFY requests sent by the 3cx which include the "Subscription-State=terminated;reason=timeout" header.
B. The 3rd underlined 403 is a response to a SIP NOTIFY sent by 3cx, which is for my Polycom's subscription to its own ext. 6240, and includes a "Subscription-State=active;expires=3600" header.

My questions:

1. What triggers 3cx to send NOTIFY requests to the Polycom? I am not sure I have spotted the pattern here.
2. Why does Polycom respond to 403 to those requests every once in a while? (still have not spotted the pattern).

Thank you in advance,
George

 

[George Ts]

As a follow up here, right before 3cx sent those NOTIFY's, the Polycom had sent SIP SUBSCRIBE requests with “Expires:0” header.
So, to sum up, the flow is:

1. Polycom sends three (3) SIP SUBSCRIBEs to our 3cx server, 2 of which are for its own registered line (reg.1.lineKyes=2) and one of which is for a 3rd user (John) that the Polycom monitors via BLF. All three SUBSCRIBEs include the “Expires:0” header.
2. The 3cx server sends three SIP NOTIFYs to the Polycom, all including "Subscription-State=terminated;reason=timeout" header
3. The Polycom responds with 403, produces a failure sound and instantly restarts

This now sounds like the root cause are the first SUBSCRIBE requests that the Polycom sends with Expires=0.
Any suggestion, any idea here why this happens, would be more than welcome.

Regards,
George

 

[George Ts]

Hi 3cx team,

Getting back to you because the exact same issue happened with a Conference IP Phone (Polycom SSIP7000).
A SIP NOTIFY with Subscription-State=terminated;reason=timeout forced the SSIP7000 to reboot.
That NOTIFY came out of the blue, since the previous subscription needed 57 more seconds util it would expire.
@YiannisH_3CX @Aram just tagging you here because you have assisted me before.
Do you think there might be any input from your side on this one?

Thank you,
George

 

[lneblett]

Look at the event. This is the field that will provide some info about what the Notify was about.

When the Polycom reboots, it may broadcast or simply register wherupon 3CX may send a Notify with an event = ua-profile, which should then cause the Polycom to retrieve its configuration. An event = check sync may cause a reboot.

The 403 is a declined. Your phone may require an authentication before it will execute the request. Some can be made to not request the authentication.

Perhaps you manually provisioned the phone and the credentials within 3CX changed?

 

[George Ts]

Thank you for reaching out @lneblett
The Event is always message-summary.
The Polycoms are automatically provisioned by 3cx.
In today's occurrence, the Conference Phone just received from 3cx a SIP NOTIFY which terminated its subscription long before it was expected to expire. Right after, a reboot took place.

 

[YiannisH_3CX]

Hello @George Tsionos

When the phone sends a Subscribe message with the Expires value set to "0" it is basically un-subscribing from the BLF or the line key.
Notify messages can be sent for a number of reasons as it is the method used by the PBX to alert the phone. A Notify message will be sent if the BLF the phone is monitoring is on a call and if the call has ended. Or even if the extension has a Voicemail waiting.
From your description you are getting the error because the phone is no longer subscribed to the BLF.
I have been trying to replicate the behaviour you are describing using a VVX500 all day without success. I have not seen the phone un-subscribe yet. What firmware are you running on the phones?

 

[George Ts]

Hi @YiannisH_3CX
Thanks for reaching out.
I really wish I had more feedback to send here, but unfortunately this has not happened again since last week.
I have been monitoring Polycom's syslogs ever since, but the issue has not been reproduced.
If - for any reason - you might have any more feedback, please let us know.
I will make sure to update this post if I have any findings on my side.

Thank you,
George