Forum Discussion

David Przywara's avatar
David Przywara
Copper Contributor
Apr 26, 2023

Yealink MP56 with Teams SBA Issue

Has anyone gotten Yealink MP56, or any other Teams IP phone working with SBA? We've been testing failover to SBA by restricting access to the internet for Teams devices. The Windows desktop client fails over to SBA without issue. The desktop client shows the banner of lost internet access and continues to make/receive PSTN calls. The Yeallink phones never show a banner, and can't make/receive PSTN calls. We have support cases open with Microsoft and Yealink but they have not gone beyond collecting logs.

Calling
SBA
teams
  • beyonduc's avatar
    beyonduc
    Copper Contributor
    Jun 30, 2023
    Hi,

    Did you have any chance to resolve this issue? I have similar scnario but with Yealink MP54 phones.
    Any suggestions?

    Regards
    • David Przywara's avatar
      David Przywara
      Copper Contributor
      Jun 30, 2023
      We resolved the issue yesterday with Microsoft escalations support. There is a bug with IP phone firmware where they do not support wildcard certificates used on the SBA appliance. Generating a CSR on the SBA and getting that signed resolved the issue.
      • Shalid_Chalil's avatar
        Shalid_Chalil
        Copper Contributor
        Jul 03, 2023

        Thanks David Przywara 

         

        We are not using a wildcard, I have shared certificates for the SBC and SBA.  I reproduced the issue by blocking the internet access to the phone. But no luck, it never shows the banner for disconnection. Also, it doesn't allow users to make or receive any calls. strangely I cannot even see the phone connectivity details in the SBA. All the team's clients except the phones are in the connected team clients. 

         

        The phone firmware is updated and it is in the latest.  to be safe, I have uploaded the root CA certificates to the phone. 

         

        Any suggestions ..

         

        Regards