Skip to main content


Direct Routing March 2019 Updates (Part 1 of 5)

Web API Using Azure

Last year Microsoft released something referred to as BYOT (Bring Your Own Trunk). Upon its GA release, this was renamed to Direct Routing for Microsoft Teams. Direct Routing is very similar to the offering in Skype for Business Online (CCE) however Direct Routing will not require the large footprint that was required for Cloud Connector Edition (CCE) in Skype for Business Online. Since Direct Routing is such a big topic, this will be structed into a 5 part series. In this first article we’ll be discussing what Direct Routing is, the benefits of Direct Routing, and certain considerations that will need to be accounted for before implementing Direct Routing in your environment.

Direct Routing 101

  1. Slow down there buckaroo…Before we jump into Direct Routing, it crucial to understand how Microsoft Phone System ties into this offering. Microsoft Phone System is an offering by Microsoft which provides PBX functionality for your users. Once your users have this license type applied (to be discussed in more detail later) they will need some way to dial out to the PSTN. This is where you will have two options:
    1. Direct Routing
    2. Calling Plans

For the purpose of this article we will only be discussing Direct Routing but just know that you have two options that are provided by Microsoft. In short, having Phone System paired with Microsoft Calling Plans and/or Direct Routing will provide your users the full enterprise calling experience for Office 365. Now that we understand the importance of Phone System in Microsoft Teams, we can take a closer look at Direct Routing.
With Direct Routing a user will first connect to the Office 365 cloud with the Phone System license addon for Microsoft Teams. The Microsoft Phone System then connects to a certified SBC. The SBC in turn can be connected to an existing PBX and/or any analog telephony adapter and finally connects to a PSTN trunk which leads to the PSTN network. We will discuss these steps in more detail later in this article but for now, just know the flow at a high level.

Direct Routing Benefits

Direct Routing won’t be for every organization but for those that this does cater to, this solution can be quite beneficial for those looking to have their calling functionality in the cloud. Some of the key benefits of Direct Routing include:

  • Interoperability with 3rd party PBX’s
    • Many organizations still maintain an on-premises PBX (Avaya, Cisco, etc.) and are unable to get rid of their current PBX due to functionality that is not currently offered by Microsoft. With Direct Routing, users can now route Teams calls directly to your on-premises PBX and users on Teams can call those still on your legacy PBX.
  • Leverage contracts with existing service providers.
    • If you just renewed a contract with your existing PSTN provider you won’t have to worry about ending this contract and sustaining a hefty early termination fee for that contract. As long as you have the SBC and Direct Routing in place, you will be able to terminate your calls on the Teams client while still benefitting from the PSTN services provided by your current service provider.
  • Everyone gets a dedicated DID!
    • Yep, you heard that right! As long as you have a Phone System license assigned every user will get their own phone number that can be directly called.
  • Direct Routing can be used where calling plans are unavailable
    • Not all countries will be able to leverage Calling Plans provided by Microsoft. Fear not, Direct Routing is a great option to ensure all of your customers have telephony capabilities.
  • Combine Direct Routing and Calling Plans
    • Trying to move to Calling Plans but realize that some locations don’t have it available? Don’t worry you won’t be forced to choose one or the other. You will have the availability to combine Direct Routing and Calling Plans and configure certain calls to use Direct Routing and other calls to use the Calling Plans!
  • Less hardware footprint!
    • If you’re coming from Skype for Business, you may remember the concept of CCE (Cloud Connector Edition) which had very similar results as Direct Routing but required you to run VM’s on a Windows Server. With Direct Routing all you’ll need is a SBC or better yet have a partner host the SBC on your behalf and eliminate the hardware footprint all together!

Direct Routing Considerations

Now that we’ve covered what Direct Routing is and how it can benefit your organization, let’s discuss some things you’ll want to consider before implementing Direct Routing.

Service Numbers

Service numbers are special phone numbers dedicated for a high concurrency of calls (Call Queues, Auto Attendants, and Dial-in Conferencing). At current state, it is not possible to leverage Direct Routing for service numbers. However, you do have the option of porting your number over to Microsoft and then using this ported number as your service number.
Note: Call Queues and Auto Attendants are expected to support numbers via Direct Routing within the next few months.

Skype for Business Hybrid

If you are in a hybrid scenario where you have some users in Skype for Business on-premises and others in Skype for Business Online, you’ll need to ensure users are homed in Skype for Business Online if they will leverage Direct Routing.

Emergency Calling

One very important consideration for your end users will revolve around the concept of emergency calls. Emergency calls differ in Teams from your traditional telephony systems. In the past each phone line was tied to a specific location so if an emergency call came from a designated number you would know exactly where the user was calling from. However, in Teams users are constantly moving and roaming around and aren’t tied to one location. Instead, Teams uses location information based on the phone provider. With that said you will need to educate your users of the following:

  1. Teams might not know the actual location of a caller
  2. If your device has no power, you won’t be able to call out (no power = no phone)
  3. If you leave the office country/region DO NOT use Teams for emergency calls (use your cell phone instead)

For more details on emergency calling, check them out here.
This concludes today’s blog article on Direct Routing. In the next article we’ll discuss the Direct Routing Call Flows which will be crucial in your understanding of how Direct Routing works on the backend.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Brian Siefferman

Brian is a Technical Consultant for Perficient’s Unified Communications practice focusing primarily on Skype for Business and Microsoft Teams workloads. He has been in this role since December 2017 and has an active presence blogging about all things Teams related. Currently, Brian resides in the suburbs of Chicago and enjoys running, swimming, weight lifting, and playing soccer in his free time.

More from this Author

Follow Us