Microsoft Teams
Direct Routing for Microsoft Teams. Multi-tenant.
Thirdlane is a certified-pattern Direct Routing SBC for Microsoft Teams. Run Teams calling through the carrier of your choice, on the same multi-tenant platform that runs your Connect users, your SIP phones, and your contact center — one dial plan, one set of trunks, one operator console.
Why route Teams through Thirdlane
Bring your own carrier
Stay on Microsoft Teams for collaboration but route PSTN through any SIP carrier you choose — keep negotiated rates, regional numbers, or carrier features that Microsoft’s Calling Plans don’t cover.
Per-tenant Direct Routing
On Thirdlane Multi-Tenant PBX, the same install acts as the Direct Routing gateway for many Teams customers — each tenant routed independently with its own dial plan and outbound routes.
Unified dial plan
Teams users dial the same internal extensions, IVRs, and queues as Connect users on the same tenant. Cross-platform calling, transfers, and presence — one platform underneath.
Selective enablement
Move users to Teams calling at your own pace. The same tenant can host Connect, Teams, and SIP-phone users side by side.
What you’ll need
Microsoft 365 license
Office 365 Enterprise E3 + Phone System, or Enterprise E5. Required per Teams user routed through Thirdlane.
Public TLS certificate
Standard SSL/TLS for the Direct Routing endpoint. On Thirdlane Multi-Tenant PBX, a wildcard certificate covers per-tenant subdomains.
DigiCert Global Root G2
Microsoft’s SBC peer requires the DigiCert Global Root G2 in the trust store; Thirdlane includes installation steps in Configuration Manager.
Direct Routing TLS port
A reachable TLS port for SIP signaling (configured in System Management → Telephony Settings → Microsoft Teams). Open in your firewall and any upstream NAT.
Setup at a glance
End-to-end configuration is documented step-by-step in the Thirdlane platform docs. The high-level shape:
Step 1
Configure SBC trunk
In Thirdlane: Telephony Settings → Microsoft Teams. Enter base domain, signaling port, and upload certificate, key, and root chain.
Step 2
Register the SBC in Teams
In Microsoft Teams admin center, register the Thirdlane SBC and create a PSTN voice route pointing to it.
Step 3
Voice routing & dialplan normalization
Define number normalization rules and voice-routing policies that send the right calls to Thirdlane vs. native Calling Plans (if any).
Step 4
Provision Teams users
Per Teams user, set the line URI and assign the voice routing policy. In Thirdlane, configure the matching extension under the right tenant.
For the full walkthrough including screenshots, see the migrated step-by-step blog post.
Side-by-side with Connect
Teams users and Thirdlane Connect users live on the same tenant. Internal extensions, IVRs, queues, and recording policies apply uniformly — pick the client per user, not per organization. Service providers operate the same dial plan whether the customer is a 20-seat Connect shop or a 5,000-seat Teams deployment.
Walk through Direct Routing.
We’ll show you the per-tenant SBC config, the Teams admin center setup, and how the same platform handles Connect, Teams, and SIP phones together.