Do I have to migrate off Teams Phone?

No. Teams Phone stays your phone system. Open is a SIP destination on the AAs/CQs you choose.

Direct Routing or Operator Connect — which should I use?

Use whichever you already have. Direct Routing is more common for organizations with their own SBC; Operator Connect is cleaner if your operator partner already supports it.

For Direct Routing, yes — Microsoft requires a certified SBC. For Operator Connect, no.

Do I need extra Teams licenses for the AI?

No. The AI is a SIP destination, not a Teams user.

Can the AI escalate to my Teams users?

Yes. SIP REFER returns the call to a Teams user, Auto Attendant, or Call Queue with the transcript attached.

What does this cost on top of Teams?

Microsoft keeps invoicing Teams Phone licenses and calling plans. Open charges per resolved conversation.

Yes — Teams Direct Routing requires TLS for SIP signaling and SRTP for media. Both are supported by Open.

UCaaS

Open for Microsoft Teams

Pair Open with Teams Phone via Direct Routing or Operator Connect and the AI picks up — your Teams users, numbers, and admin center stay unchanged.

Try now

Setup time: Under 30 minutes
Auth: Direct Routing SBC pairing or Operator Connect
Directions: Inbound · Outbound · Call transfer
Pricing: Included with Open

01 — Overview

Can I add an AI phone agent to Microsoft Teams Phone?

Yes. Teams Phone supports external SIP routing via Direct Routing (with an SBC) and via Operator Connect partners. Open joins as a destination on either path; your Teams users, numbers, and admin center stay where they are.

Microsoft Teams Phone remains the phone system. Users, devices (Teams desktop/mobile, certified Teams phones, headsets), Auto Attendants, Call Queues, dial plans, and the Teams admin center all stay in place. Open joins as a SIP destination either through Direct Routing (you pair a Session Border Controller to Open) or by being routed to via a Call Queue / Auto Attendant external transfer.

For Direct Routing, the typical setup uses an SBC like Ribbon, AudioCodes, Oracle, or AWS-hosted SBCs. You add Open as a SIP peer the SBC can route to, and configure a Teams voice route that targets Open for the call patterns you want AI'd. Teams handles the user side, Open handles the AI side. SIP REFER takes care of escalations back to Teams users.

For Operator Connect, the integration is even cleaner: an Operator Connect partner brings the carrier connection, and Open lives behind it as a SIP destination the partner trunk can route to. From Microsoft's perspective, calls land on a normal Teams number and route via Auto Attendant / Call Queue — Open is the destination on the branch you opt-in.

What the AI does on the call: it listens, reasons over your knowledge base and connected tools (Microsoft 365 Graph, Dynamics 365, Salesforce, ServiceNow, Zendesk, calendar, payments), and acts. When the AI needs a human, it warm-transfers back to a Teams user, Auto Attendant, or Call Queue via SIP REFER, with the live transcript and detected intent posted to the call leg in Teams' analytics.

Billing stays predictable. Microsoft keeps invoicing your Teams Phone licenses and any Microsoft Calling Plan minutes. Open charges per resolved conversation, with no markup on Teams minutes and no extra Teams licenses needed for an AI front-line.

What stays the same on Microsoft Teams

Teams users and devices
Licenses, certified phones, and the Teams app don't change.
Numbers and dial plans
Teams Phone numbers (or BYOC numbers via Direct Routing) stay where they are.
Auto Attendants and Call Queues
Existing AAs and CQs keep working. Open is one external transfer destination on the branch you choose.
Teams admin center
You manage the phone system the same way.

What's new with Open

A SIP destination behind your SBC
Open's SIP URI is added as a peer behind your Direct Routing SBC, or as a destination on an Operator Connect trunk.
AI handles the conversation
On opted-in branches, the AI greets, listens, calls your tools, and replies in natural speech.
Transfers carry context
Escalations to a Teams user, Auto Attendant, or Call Queue receive the live transcript via SIP REFER.
Pricing model
Open per resolved conversation. Teams Phone licenses and calling plans stay invoiced by Microsoft.

02 — Why this works

The native Microsoft Teams experience

Direct Routing or Operator Connect
Both paths supported — pick whichever your Teams environment already uses.
No new Teams licenses for AI
AI is a SIP destination, not a Teams user — your license count doesn't change.
Per-AA / per-CQ opt-in
Pick exactly which Auto Attendants or Call Queues route to AI.
Warm transfer back to Teams users
When the AI escalates, the call returns to a Teams user, AA, or CQ with the transcript attached.

03 — Setup guide

Wire up Microsoft Teams in under 30 minutes

Two trunks — one inbound, one outbound. Both configurable from Settings → SIP in the Open dashboard.

1
Open Settings → SIP
Open the inbound trunk configuration.
2
Pick a SIP region
Choose Global, US, EU, or APAC.
3
Copy the SIP credentials
Grab the SIP endpoint, username, and password.
4
Pick the Teams target
Decide which Auto Attendant branch or Call Queue should route to AI.
5
Add Open as a destination
Direct Routing: add Open as a SIP peer behind your SBC and create a Teams voice route. Operator Connect: have your operator point a trunk at Open. AA/CQ: configure External Transfer to the Open SIP URI.
6
Add the matching numbers to Open
Under Phone Number (DID), add the Teams DIDs that fronted the AA/CQ.
7
Assign numbers to an AI agent
Channels → Phone → Agents → assign DIDs.
8
Place a test call
Dial a Teams number and confirm Open answers when the AA/CQ branches to AI.

04 — Configuration

Settings → SIP, at a glance

A real inbound trunk for Microsoft Teams looks something like this. Yours are generated when you open Settings → SIP.

Inbound trunk · Teams

Sample

SIP endpoint: sip.us.opencx.comUS region
Transport: TLSrequired by Teams
Pairing: Direct Routing SBC
Voice route: OpenAI-Route
Auth: TLS + IP allowlist

05 — Security

Encrypted, audited, refundable

SIP over TLS for signaling, SRTP for media. Every call is logged with full reasoning traces. SOC 2 Type II, GDPR-aligned, HIPAA- and PCI-ready. Backed by the Open $2M Refund Guarantee.

06 — FAQ