Derived Trunks – Expand Your SBC for Teams Calling Across Multiple Microsoft Tenants
July 26, 2021
Tim Jalland, Solution Manager (Microsoft Teams)
It’s a neat and recent feature on the Microsoft Teams front that I’m not sure all carriers are using to the full. In this context, the term “carrier” refers to the company – or partner – that provides telephony, PSTN, calling, or enterprise voice services (all the same thing by a different name really) to a number of customers that are using Microsoft Teams as their collaboration and UC platform.

Normally, the carrier would require a trunk to be added to the Microsoft Teams tenant for each customer that is consuming the telephony service. The service delivery uses Microsoft Direct Routing. More often than not, the SBC at the end of all these trunks is the same one (multi-tenanted), supporting all customers on the service.
That brings overhead (making configuration changes, taking actions such as draining calls, changing ports), means doing these actions trunk by trunk across all customers, and is very time consuming for carriers. And the annoying fact is that, in reality, all these trunks are running from the same multi-tenant SBC and the same configuration.
Enter Microsoft Teams Derived Trunks!
Microsoft Teams now supports the ability to create one ‘super trunk’ that is registered in the Microsoft tenant for the carrier itself. Then a so-called Derived Trunk can be used within each of the individual customer tenants, simply by adding the trunk into any respective voice routing policy (no need to register). The beauty is that these derived trunks take or inherit their configuration from the parent carrier trunk, so now configuration changes and actions can be quickly and easily applied by making changes to this single parent carrier trunk; without having to go into every individual customer tenant and make a repetitive change. Time saved!
Want to then take this to the next level? Deploy the VOSS management suite and you’ll bring a level of assurance, self-service administration, and automation to this Direct Routing service that will make it stand out from your competitors.
Hopefully you found the above helpful, please drop us a line with your feedback.