3pip phones ice issue

Brass Contributor

Any suggestions how to resolve the following issue

poly vvx (and for testing trio in sfb mode).No audio when making a call to internet. Ie making a pstn call (ms calling plan) or calling another teams client on the internet fail.

When calling user on same network two way audio without issue.

Tested on multiple networks including home network.

Tenant is teams only (new tenant)


Same phones on same network logged in to other tenants work fine.


My assumption is issue is not phones nor network as works to other tenants.

Accounts used to login with, when logged in with teams client on pc work perfectly.

5 Replies
best response confirmed by Alistair Keay (Brass Contributor)
So ive actually ran into this. This has something to do with the backend where the tenant was never originally provisioned for Skype for Business Online (IE After September 2019). The tenant that I have this issue in cannot get two-way audio on any 3PIP devices. It works on the same network as media can flow directly to the other device, but when it cannot, it relies on the Microsoft Cloud Interop Gateway. The only resolution here would be to contact Microsoft Support and request that SFBO be provisioned for your tenant.

@Eric Marsi 

brilliant, thanks

i have a case open and was getting a bit desperate as it wasn’t progressing 

this will help a lot




Eric I dropped you a mail. I was wondering if you have an old MS case reference to the issue you had and resolved _ as this might help with my case etc
Responded there :)
Adding notes in case others hit the issue
MS case finally reached a very good engineer and conclusion was

1. Tenant is in a forest which doesn’t have Media Relays deployed, but only Transport Relays. Transport Relay is latest Relay services for Teams and requires MRAS version 3.0 or higher for STUN/TURN requests to succeed.
2. However most 3PIP phones are at MRAS 2.0 only and hence the TURN requests are failing.
3. So the resolution is to move the tenant to a forest that have Media Relays.
4. This Tenant move between forest is recommended during weekends as Teams/Outlook user might get disconnected briefly during the forest migration.

While the resolution worried me a lot
It went very smoothly and we now have working 3pip phones... which I am desperate to replace... but till then.
Thanks again Eric as well