November 7, 2018 – Microsoft Cloud Infrastructure Technical Journal

Our internal IT team was in the mission of setting up calling feature of Microsoft teams ad we discovered that the calls are not directly routed to user devices. Users can dial out from Teams clients, Desktop and mobile both however, Teams client automatically diverts incoming calls to voice mailbox.

With this post, I am going to explain through the steps of the analysis of the issue and how we managed to configure Teams coexistence mode to route incoming calls to the Teams client.

During our discovery:

We went through Call forwarding settings in Teams client on several devices (Teams Client > Settings > Calls > Call Forwarding Settings) and figured out that call forwarding is disabled. Which basically proves our first assumption is out. Client side forwarding option isn’t the cause of this issue.
Then checked Skype for business admin center to find out if any helpful entries are there as it provides PSTN usage detail reports on inbound or outbound calls. Anyhow, this had nothing to offer in our case so that’s out as well.

However, having a Microsoft calling plan to connect to the PSTN is mandatory. Ensure that you have a calling plan applied to your tenant and then you can go ahead and assign phone numbers to your users from Skype for Business and Teams Admin Centers. Calling plans are detailed in this Microsoft write-up.

Call routing is depends on the coexistence mode configurations defined in the Teams & Skype for Business Admin Center. Coexistence offers the flexibility of configuring in two different scopes.

User context
Tenant context (Organization wide)

It simply means that, if you configure the coexistence in user context mode while tenant context exists too, tenant context will be overwritten by the user-context mode. Above chart explains the behavior of each scenario.

Now in our scenario, this tenant was configured as the coexistence mode islands, hence any of our calls were automatically transferred to the Skype for Business client. However, because we didn’t have Skype for Business downloaded on our devices, we didn’t receive any of these calls. Once we had updated these settings and waited for it to sync with Office 365, calls were simply received in Teams client.

Here are the steps taken to achieve this. First, log in to your Office 365 tenant using Global Admin account, and, head on to Admin centers –> all Admin centers –> Click on “Teams and Skype”