First, it is important to understand Calling Plans and Direct Routing in detail.
On this slide, one company uses two options without co-existence. There are two types of users using either Calling Plans or Direct Routing. The systems are discrete. All PSTN calls for users with Calling Plans are made via the Calling Plans, while calls for users with Direct Routing are made via Direct Routing.
If a Teams user with a Calling Plan calls a user with Direct Routing, the call will be converted to Voice over Internet Protocol (VoIP) and the connection will be established between two clients without going to the telephony network.
The second configuration is mixed for the same user – Calling Plan and Direct Routing. In this example, the user has a Australian TCO 365 Calling Plan. At the same time, the user also has some calls routed via Direct Routing.
For example, when a call goes to any Australian number (with +61) the TCO 365 Calling Plan route is taken. But there is also an option to configure routes to some destinations using Direct Routing