Monday, March 9, 2020

"Have you tried turning it off and back on again?" for MS Teams

One of the most powerful tools in a support professional's arsenal is the tried-tested-and-true method of restarting a computer to resolve strange issues. I can't tell you how many times this fixed the oddest issues over the years. Why does it work? You might as well ask where socks go once placed in the clothes dryer.

I'm excited/sad to report that the same method works in Microsoft Teams to resolve strange issues that defy explanation. I'm not talking about client-side issues. I'm talking about issues at the Office 365 end of things. How does that work when there are no administrator-accessible servers to restart? You simply toggle the relevant setting off and back on again.

We use Direct Routing for our PSTN services, and for the most part it works great. In the past few weeks, I've had some of our users experience strange issues with telephony in Teams.
  1. A few users were unable to receive any PSTN calls. Troubleshooting at the SBC would show 487 Request Terminated - Phone number not found.
  2. Another user's outbound PSTN calls were showing as Anonymous/Private. There weren't any caller ID policies being applied that would account for the behaviour.
For each of those issues, I verified that things were indeed setup properly in Teams via PowerShell. Get-CsOnlineUser showed that their LineURI and OnpremLineURI settings were correct, and Enterprise Voice was enabled. Get-CsOnlineVoiceUser showed they were all licensed, PSTNConnectivity was OnPremises and their Number was correct.

In short, there was nothing on the Teams side of things that indicated an issue. I decided to try the "Have you turned it off and back on again?" trick, which consisted of:
Set-CsUser -Identity -EnterpriseVoiceEnabled:$FALSE
Set-CsUser -Identity -EnterpriseVoiceEnabled:$TRUE

I waited patiently all of 10 seconds between commands. I then instructed the users to log off and back onto Teams. Lo and behold, in each case, the problem went away.

Yeah, I know. I don't get it either, but works.


  1. Ha, figures. I've never used microsoft teams, I'm strictly a cisco voice kind of guy, but I guess that's primarily because the opportunity has never come up for me to use it. But it figures that Microsoft would have weird issues like that.

  2. About 10 days ago in 2 different O365 Tenants, I had a Teams user that was assigned a Dial Plan policy (4 digit in this case) and we test dialed a 4 digit number and proper normalization worked. A few days later, 4 digit dialing was no longer working, again, in 2 different tenants. In both tenants the fix was putting the user in global DP and then putting them right back in the custom dial plan policy. Turn it off, Turn it on, jiggle the handle.

  3. I've seen this a few times too, good to know others are seeing the same, thanks!