In short
Microsoft Teams Direct Routing connects Teams Phone to a carrier or SIP trunk of your choice through a Microsoft-certified Session Border Controller (SBC). Each user needs Microsoft Teams and a Teams Phone licence; no Microsoft Calling Plan is needed. Forever Systems can quote Direct Routing as a service, with the SBC run for you and your numbers kept.
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What Direct Routing is
Direct Routing is one of Microsoft's four ways to connect Teams Phone to the public phone network. Microsoft describes it (opens in a new tab) as connecting your own telephony infrastructure to Teams Phone through a supported Session Border Controller (SBC), so an organisation can use existing carriers, integrate third-party telephony systems and keep more control over its voice infrastructure.
The SBC is the bridge. On one side it talks to Microsoft's Direct Routing service; on the other it talks to SIP trunks, a phone system or analogue devices. Microsoft says the SBC can be procured, installed and managed by you, by your integrator or by a Direct Routing as a Service provider.
When Direct Routing suits
Microsoft lists Direct Routing as a good fit for organisations that:
- Have an existing carrier relationship
- Need to integrate third-party phone systems or analogue devices
- Need advanced voice routing
- Want greater control over their telephony infrastructure
- Run complex or multinational voice deployments
It is also how a UK provider can deliver Teams calling with numbers kept and its own call billing, which is what our Teams calling service does.
How Direct Routing works
| Part | What it is |
|---|---|
| Certified SBC | A Session Border Controller that Microsoft has certified for Direct Routing |
| Trunks | One or more connections from the SBC to a carrier |
| Domain and certificate | The SBC's name sits in a verified Microsoft 365 domain and holds a public trusted certificate |
| Signalling | SIP over TLS between the SBC and Microsoft's three Direct Routing connection points |
| Media | Encrypted audio through Microsoft's media processors, or direct between the user and the SBC with media bypass |
| Licences and routing | Microsoft Teams and Teams Phone for each user, with voice routing assigned |
Teams Direct Routing requirements lists each requirement, and Teams Direct Routing SBC explains the controller's job.
Not sure which option fits? Ask us
Tell us what you need and we will recommend the right option for your organisation, with a quote.
Ways to run Direct Routing
| Model | Who runs the SBC | Often suits |
|---|---|---|
| Your own SBC | Your IT team, on site or in your own cloud | Large estates with in-house voice skills and specific integration needs |
| Integrator-managed | A specialist that builds and looks after the SBC for you | Organisations with an on-site phone system or analogue estate |
| Direct Routing as a Service | The provider, in its own cloud | Organisations that want Teams calling with no equipment to run |
Microsoft Teams Direct Routing providers describes the service model and what we provide. Call2Teams uses the same model to bring an existing phone system or SIP trunk into Teams.
Direct Routing alongside other options
Microsoft supports Direct Routing in the same tenant as Calling Plans, Operator Connect and Teams Phone Mobile. Its planning guide describes a common pattern: a Calling Plan or Operator Connect for general calling, with Direct Routing for calls to third-party phone systems, for analogue devices and for specialised routing. Operator Connect vs Direct Routing vs Calling Plans compares the options.
Is Microsoft Teams Direct Routing the right fit for you?
We will check it against your systems and requirements and recommend the right option.
Things to plan for
- Support boundaries. Microsoft supports Direct Routing only with certified SBCs. A fault goes first to the SBC vendor, which escalates to Microsoft if needed.
- Emergency calls. Each site needs an emergency location, so an emergency call presents an address.
- Auto attendants and call queues. With Direct Routing numbers, a resource account that makes outbound calls needs an online voice routing policy.
- Shared devices. Microsoft notes that a shared device in a common area needs no Calling Plan licence when Direct Routing is used.
- Teams mode. Microsoft states that Direct Routing is not supported in Islands mode.
How we help with Direct Routing
We deliver Direct Routing as a managed service, so it is set up and run for you and needs no equipment on your site:
- We review your numbers, carrier and any phone system or analogue lines you need to keep.
- We supply the Teams Phone licences and set up voice routing and emergency addresses.
- We port your numbers and assign them to users, auto attendants and call queues.
- We test inbound and outbound calls and transfers with you before the switch.
Contact us for a Direct Routing quote.
Sources (checked 11 November 2026): Microsoft Learn, "Plan Direct Routing", "PSTN connectivity options" and "Reference - Voice applications prerequisites and licensing".
Direct Routing in detail
How Forever Systems helps with Teams Phone
Forever Systems can quote and set up Microsoft Teams Phone for your organisation and connect it to the phone network.
- Licence and calling check: we look at the Microsoft 365 plan you hold and recommend the Teams Phone licences and calling option that fit
- Numbers kept: we plan and manage the porting of your existing numbers
- Call flows set up: auto attendants, call queues and opening hours built and tested with you
- Works with what you use: the Teams apps on desktop and mobile
- Licensing in one place: licences can be billed monthly, with terms confirmed at quote
We work with businesses, schools, charities and public sector organisations. Pricing depends on users, licences and calling, so ask us for a quote.
Frequently asked questions
What is Direct Routing in Microsoft Teams?
Direct Routing connects Microsoft Teams Phone to a carrier, SIP trunk or phone system of your choice through a Microsoft-certified Session Border Controller. The controller can be run by you, your integrator or a Direct Routing as a Service provider.
What licences does Teams Direct Routing need?
Microsoft requires each Direct Routing user to hold Microsoft Teams and a Teams Phone licence. A Microsoft Calling Plan is not needed, because the calls are carried by your carrier or Direct Routing provider.
Do I need my own Session Border Controller for Direct Routing?
No. With Direct Routing as a Service the provider runs the certified Session Border Controller in its own cloud, so there is no equipment on your site. Our Teams calling service works this way.
Can Direct Routing be used with Calling Plans or Operator Connect?
Yes. Microsoft supports Direct Routing alongside Calling Plans, Operator Connect and Teams Phone Mobile in the same tenant, so different users or sites can use different options.
Can analogue devices work with Teams Direct Routing?
Yes. Microsoft lists integration with analogue devices as one of the reasons to choose Direct Routing. They connect behind the Session Border Controller.
Still have a question about Microsoft Teams Direct Routing?
Ask us and a member of our team will get back to you.