What is the difference between Direct Routing and Operator Connect?

Teams Phone is a phone system, and it needs a carrier before anyone can call an outside number. Microsoft's PSTN connectivity page lists four ways to add one. A Microsoft Calling Plan makes Microsoft the carrier. Teams Phone Mobile uses a mobile operator and the number on a user's SIM. Operator Connect and Direct Routing are the two routes that use a landline carrier other than Microsoft, which is why they get compared.

On both routes every user needs a Teams Phone license. When an operator other than Microsoft supplies the calling, Microsoft's licensing page requires no further license, because those costs come from the operator. So the Teams Phone license requirement is the same on both routes. The carrier's charge and the cost of the connection are the parts of what Teams Phone costs that vary. People make and take calls in the same Teams app on both. The differences are behind the app, in who builds the connection and who looks after it.

Operator Connect is a program. A carrier joins it by completing the integration with Microsoft and being certified. Microsoft's planning page for Operator Connect says the operator manages the phone network infrastructure, and your administrators manage users from the Teams admin center.

Setting it up is a matter of choosing and assigning. You sign a contract with a participating operator and enable that operator in the admin center. You then get numbers, either new ones from the operator or existing ones ported over, and assign them to users. Microsoft lists a few prerequisites: Teams Phone licenses, users in Teams Only mode, the right administrator permissions, and an operator that serves the countries where you need service.

That last condition limits the choice of carrier. It has to be an operator in the program, and each one serves particular countries.

Support is shared, and Microsoft's planning page says where the line falls. Microsoft is responsible for Teams, the admin center and the integration with Operator Connect. The operator is responsible for the phone network connection, number provisioning and porting, the calling service and troubleshooting on its side.

Direct Routing has no carrier list. In Microsoft's words, you can use any PSTN operator. The connection is made through a session border controller, or SBC, a device that sits between the carrier's network and Teams. Microsoft supports only the SBC models it has certified.

Somebody has to make that connection work, and the planning page for Direct Routing lists what it involves. The SBC needs one or more carrier trunks. It needs a public IP address that Teams can reach. It also needs a fully qualified domain name under a domain verified in your Microsoft 365 tenant, with a public DNS entry and a trusted certificate for that name. The firewall has to allow Microsoft's signaling and media traffic. Then come voice routes, dial plans and the routing policies assigned to users.

Microsoft gives the reasons an organization takes that on. The planning page says Direct Routing fits organizations that have an existing carrier relationship, need to connect a third-party PBX or analog devices, need advanced call routing, want more control over their telephony, or run complex or multinational deployments.

Support follows the equipment. Microsoft's guidance for Direct Routing is to contact the SBC vendor when a problem occurs. The vendor investigates and escalates to Microsoft if needed. When a provider runs the SBC for you, your first call is to that provider under its support terms.

The SBC for Direct Routing can be procured, installed and managed by the customer, an integrator or a Direct-Routing-as-a-Service provider. A company can use Direct Routing and never own a session border controller.

Atlantech Online is an example of a carrier that sells both routes. Its Teams Calling page says that setting up Direct Routing on your own creates costs for equipment, personnel and installation, and that its service includes Direct Routing. The page lists that service as "starting at $10 per user per month," with an enterprise dial plan, call queues and optional call recording. Its Operator Connect page lists a flat rate "as low as $3 per user/month" and says Atlantech manages the calling service and the SBCs. Both figures are starting prices for the carrier's service. They cover different sets of features, so the gap between them is not the price of Direct Routing.

With a provider like that, both routes are managed services. The customer isn't choosing between owning hardware and avoiding it. The customer is choosing how much the connection can be customized. Atlantech describes the trade in its explanation of Operator Connect: Operator Connect removes the work of managing SBCs, and in exchange an organization gives up some control over call routing, customization and integration with older systems.

Running the SBC yourself remains a third choice. It leaves the SBC configuration and the voice routing policies with your own team, along with the certificate and firewall work.

Start with what has to connect to Teams. If the answer is people and phone numbers, and a carrier you're happy with is in the program for your countries, Operator Connect does the job with less to set up. If the answer includes an existing PBX, analog devices or call routing rules of your own, those are the cases Microsoft names for Direct Routing. The same goes for a carrier that isn't in the program. Mobile numbers and Microsoft's own calling plans are separate routes, covered in how to choose a PSTN connectivity option for Teams Phone.

You don't have to pick one for the whole organization. Direct Routing can run alongside the other routes in the same tenant, and Microsoft's planning page describes a common pattern. Operator Connect or a Calling Plan handles ordinary calling, and Direct Routing handles calls to a third-party PBX, analog devices and specialized routing.

Suppose a 200-person distributor has 170 office staff and a warehouse with an older phone system and analog handsets on the floor. The office staff can go on Operator Connect, with numbers assigned in the admin center. The warehouse can reach Teams through Direct Routing, assuming its equipment works with a certified SBC, and a provider can run that SBC. The office staff are Teams Phone users. The warehouse keeps its own phone system, and calls pass between it and Teams through the SBC. Each site uses the route that matches its equipment.