VVX4nn Dropping incoming calls after 10 seconds

[SteffenBaierUK]

Hello @rgsteele ,

most likely Microsoft finally removed the additional SDP value of a=rtcp-mux which was never part of the 3PIP certification and caused the audio to be sent on the same port.

Please ensure to provide some feedback if this reply has helped you so other users can profit from your experience.

Best Regards

Steffen Baier

[hmahdi@rcsi.com]

Good Morning All, 

Been facing  the same issue for quite some time now, it work intermediately on some users, on same model of different model; vvx 300, vvx400 and vvx500. All are giving same issue. 

I have brought AudioCode handset and found it work perfectly fine and it doesn't give any disconnection symptoms. 

Tried different firmware, 6.xxxx, 5.9, 5.8 It worked for sometime, after that when the calls droped it will trigger the errors; 

IceConnectivityChecksFailed
Q.850;cause=16
Forbidden
Temporarily Unavailable
IceConnectivityChecksFailed
Busy Here
Service Unavailable
EstablishmentTimeout
Server Internal Error

Logged a case with microsoft and they confirmed, its from their side; 

After consulting with our back-end team, this issue was identified as known issue for poly device. We have as well attached this case to the previously known issues already under investigation and forwarded your request to the engineering team to consider a one-time fix in the future regarding to call dropping. Our internal team advised that currently there are a lot of issue regarding to poly devices so our internal teams is working to fix those issue. Unfortunately, no ETA was provided. 

We will continue to keep an eye on this issue internally and work together with them on priority till the fix this issue. We will update you as soon as we receive any updates from the product team side. 
In the meantime, we will suggest user to use normal team's desktop apps as a workaround. 

Any workaround, as the business is heavily impacted, and ordering a new phones will take ages to arrive. 

Regards, 

[hmahdi@rcsi.com]

Hi All, 

There are many blogs and info being released by Microsoft regarding this. 

https://techcommunity.microsoft.com/t5/microsoft-teams-blog/upgrade-skype-for-business-online-3pip-p...

Despite my phones are in the compatibility list mentioned in the above blog, but still I'm facing the issue with all firmware's; 

https://learn.microsoft.com/en-us/microsoftteams/sip-gateway-plan

Look at each article date and correlate it to to when you started facing the issue

https://techcommunity.microsoft.com/t5/microsoft-teams-blog/enable-core-microsoft-teams-calling-func...

Regards, 

Hussain

[rgsteele]

Hi Steffen,

---

most likely Microsoft finally removed the additional SDP value of a=rtcp-mux which was never part of the 3PIP certification and caused the audio to be sent on the same port.

I'm familiar with the SDP value issue you are referring to, but this was something else. Indeed, the support technician I am working with advised me that it was a back-end issue related to this root certificate change: Office TLS certificate changes - Microsoft Purview (compliance) | Microsoft Learn. Curiously, there doesn't seem to have been a corresponding incident published on the M365 Service Health Dashboard...

[rgsteele]

Hi Hussain,

---

Despite my phones are in the compatibility list mentioned in the above blog, but still I'm facing the issue with all firmware's; 

I'm a bit confused about your message. Are you still having call dropping issues when using the SIP Gateway instead of the 3PIP Gateway? You may want to review this article if you haven't already: Common issues when using SIP devices with Teams - Microsoft Teams | Microsoft Learn

[SteffenBaierUK]

Hello @rgsteele m @MarkJohnson , hmahdi@rcsi.com and @jmc_123 

Can we just clarify that all of you are reporting an issue that has not occurred up to a specific date with a working phone and unchanged configuration?

Again I can only stress that our phones, going back to Lync, Skype for Business, and now the Microsoft Teams 3PIP gateway, have passed Microsoft certification and nothing has changed on our phones or what we had been tested against.

Please ensure to provide some feedback if this reply has helped you so other users can profit from your experience.

Best Regards

Steffen Baier

[hmahdi@rcsi.com]

Hello, 

Yes, its an issue with Poly phones vvx300, vvx400 and vvx500. All phones are running firmware version 6.1.x.x or 5.9. 

All the phones were working fine with SFB and when migrated to Teams as well.

It worked for quite sometime, and all of the sudden users started to complain about calls are being disconnected. 

MS Teams Support investigating the issues and I'm providing all the logs of both, Teams and Poly phones to MS. 

Hopefully this issue will be resolved. 

Regards, 

[hmahdi@rcsi.com]

tried even with the new firmware; 6.3.1.11465  unfortunately, no joy

[SteffenBaierUK]

Hello hmahdi@rcsi.com ,

Welcome to the Poly Community.

As already explained in multiple places within this topic this is to my personal knowledge not a Poly Issue.

If you look at the facts provided the Poly Phone with an unchanged configuration has been working for days, weeks, months, or even years without an issue.

Suddenly, after an assumed change by our Partner Microsoft it no longer works.

Microsoft support should reach out to the well-known people within Poly to sort this out for the customer's sake.

Please ensure to provide some feedback if this reply has helped you so other users can profit from your experience.

Best Regards

Steffen Baier

[hmahdi@rcsi.com]

Hello Steffen, 

Thank you very much for your support on this. You are right, the change made by Microsoft which cases too much hassle of us as IT and for our business. 

Regards, 

Hussain