---
title: Connect Microsoft Teams Direct Routing to TelecomsXchange
url: https://help.telecomsxchange.com/integrations/microsoft-teams/
audience: Integrations
summary: 'Teams Direct Routing talks only TLS and SRTP to a Microsoft-certified SBC,
  so TelecomsXchange can''t connect to Teams directly. Run an SBC such as AudioCodes
  Mediant or Ribbon: pair it with Teams using New-CsOnlinePSTNGateway, a PSTN usage,
  voice route and voice routing policy, and point its carrier side at sip01.telecomsxchange.com
  over UDP 5060, adding TECH_PREFIX and authenticating by IP or digest.'
updated: '2026-10-23'
verified_commit: 83b4ebc96d0081a25213776d5a8871bd04941125
---

# Connect Microsoft Teams Direct Routing to TelecomsXchange

> Teams Direct Routing talks only TLS and SRTP to a Microsoft-certified SBC, so TelecomsXchange can't connect to Teams directly. Run an SBC such as AudioCodes Mediant or Ribbon: pair it with Teams using New-CsOnlinePSTNGateway, a PSTN usage, voice route and voice routing policy, and point its carrier side at sip01.telecomsxchange.com over UDP 5060, adding TECH_PREFIX and authenticating by IP or digest.

## Teams to a purchased route, through your SBC

1. **Microsoft Teams**: Direct Routing voice route
2. **Your certified SBC** (via TLS 5061, SRTP, `+447700900123`): AudioCodes or Ribbon
3. **TelecomsXchange** (via `80039#447700900123`): sip01, UDP 5060
4. **Seller's route**: The route you purchased

This guide connects Microsoft Teams Phone to TelecomsXchange with **Direct Routing**: Teams users call out through a purchased route, and numbers bought on TelecomsXchange ring in Teams. Teams never talks to TelecomsXchange directly; a certified SBC that you run sits between them. For the full list of TelecomsXchange values, see [Connect a SIP platform](https://help.telecomsxchange.com/integrations/connect-sip-platforms/).

!!! warning
    Direct Routing requires **TLS** signalling and **SRTP** media between Teams and a **Microsoft-certified SBC**. TelecomsXchange supports SIP over **UDP only**, no TLS or SRTP, and does not accept REGISTER, so it **can't be the Direct Routing endpoint**. The SBC terminates TLS and SRTP towards Teams and talks plain SIP and RTP over UDP to TelecomsXchange.

## How does the call flow?

| Leg | From → to | Transport | Number format |
|---|---|---|---|
| Teams side | Teams SIP proxies (`sip.pstnhub.microsoft.com`, `sip2.pstnhub.microsoft.com`, `sip3.pstnhub.microsoft.com`) ↔ your SBC's FQDN, for example `sbc.contoso.com:5061` | TLS, SRTP | E.164 with `+`: `+447700900123` |
| Carrier side | Your SBC, for example `203.0.113.10` ↔ `sip01.telecomsxchange.com:5060` | UDP, RTP | Tech prefix + E.164 without `+`: `80039#447700900123` |

## Before you start

- A [SIP account](https://help.telecomsxchange.com/buyers/create-your-first-account/) with the SBC's public IP, for example `203.0.113.10`, or a VoIP login and password from **Edit Account → Add SIP Digest Auth**.
- A [purchased route](https://help.telecomsxchange.com/buyers/find-and-buy-routes/) and its tech prefix from **My Interconnections**, for example `80039#`.
- An SBC on Microsoft's [certified list for Direct Routing](https://learn.microsoft.com/en-us/microsoftteams/direct-routing-border-controllers), with a public IP, an FQDN in a domain verified in your Microsoft 365 tenant (for example `sbc.contoso.com`), and a certificate from a public CA trusted by Microsoft.
- Users with a Teams Phone licence, and Teams PowerShell (`Install-Module MicrosoftTeams`, then `Connect-MicrosoftTeams`).
- Firewall rules for both sides: the Microsoft 365 signalling and media ranges (`52.112.0.0/14`, `52.122.0.0/15`) on TLS 5061 and the SBC's media ports, and `174.136.44.213` on UDP 5060 and your RTP range.

## How do I connect Teams to the SBC?

Run these in Teams PowerShell. They're the minimum for one SBC and one route; see Microsoft's Direct Routing documentation for the full options.

1. Add the SBC as a PSTN gateway:

```powershell
New-CsOnlinePSTNGateway -Fqdn sbc.contoso.com -SipSignalingPort 5061 `
  -MaxConcurrentSessions 100 -ForwardCallHistory $true -ForwardPai $true -Enabled $true
```

Use `Set-CsOnlinePSTNGateway -Identity sbc.contoso.com …` to change it later.

2. Create a PSTN usage and a voice route that sends all numbers to the SBC:

```powershell
Set-CsOnlinePstnUsage -Identity Global -Usage @{Add="TCXC"}
New-CsOnlineVoiceRoute -Identity "TCXC-All" -NumberPattern "^\+\d+$" `
  -OnlinePstnGatewayList sbc.contoso.com -OnlinePstnUsages "TCXC" -Priority 1
```

3. Create a voice routing policy and grant it to users:

```powershell
New-CsOnlineVoiceRoutingPolicy -Identity "TCXC" -OnlinePstnUsages "TCXC"
Grant-CsOnlineVoiceRoutingPolicy -Identity user@contoso.com -PolicyName "TCXC"
```

4. Give each user a Direct Routing number (one you bought on TelecomsXchange, below):

```powershell
Set-CsPhoneNumberAssignment -Identity user@contoso.com -PhoneNumber +14165551234 -PhoneNumberType DirectRouting
```

Check pairing with `Get-CsOnlinePSTNGateway` and, after a few minutes, the SBC's health in the **Teams admin center → Voice → Direct Routing**.

## How do I send calls to TelecomsXchange?

On the SBC, the carrier side is an ordinary UDP peer. The [AudioCodes SBC](https://help.telecomsxchange.com/integrations/audiocodes-sbc/) and [Ribbon SBC](https://help.telecomsxchange.com/integrations/ribbon-sbc/) guides give the exact menus; the settings are:

| SBC setting | Value |
|---|---|
| Carrier peer (AudioCodes: Proxy Set and IP Group; Ribbon: SIP Server Table and Signaling Group) | `sip01.telecomsxchange.com`, port `5060`, transport UDP |
| Registration | Off. TelecomsXchange is peering only |
| Keepalive (OPTIONS) | Off. TelecomsXchange answers OPTIONS only within a call |
| Authentication | Send from the SBC's IP authorised on the account, or answer the 401/407 challenge with `VOIP_LOGIN` and `VOIP_PASSWORD` (the account's **VoIP Login** and **VoIP Password**) |
| Media | RTP, no SRTP; G.711 or G.729 as your route supports. TelecomsXchange doesn't transcode, so let the SBC transcode if Teams and the route share no codec |
| NAT | The SBC's public IP in SIP and SDP on the carrier interface |

Add the tech prefix in the number manipulation for calls from the Teams side to TelecomsXchange: remove the leading `+`, then add `TECH_PREFIX` in front. `+447700900123` must leave the SBC as `80039#447700900123`. Then add the routing rule: calls from the Teams IP Group (or signalling group) go to the TelecomsXchange one.

!!! tip
    For several routes, add one manipulation and routing rule per destination prefix, each with its own tech prefix, or dial a [routing group](https://help.telecomsxchange.com/buyers/routing-groups-and-route-testing/) prefix such as `444101#` and let TelecomsXchange choose.

## How do I receive calls from TelecomsXchange?

Calls come from `174.136.44.213` over UDP, from source ports 5060 to 5072, with the number in E.164 without `+`, such as `14165551234`.

1. On the SBC, classify `174.136.44.213` as the TelecomsXchange peer, and allow it on the firewall for UDP 5060 and the RTP range.
2. Add a number manipulation for calls from TelecomsXchange to Teams that adds `+`, so `14165551234` reaches Teams as `+14165551234`.
3. Route those calls to the Teams IP Group. Teams rings the user assigned that number with `Set-CsPhoneNumberAssignment`.

Selling routes that terminate in Teams isn't a use case for Direct Routing: Teams only rings numbers assigned to your own users.

## How do I receive calls on numbers I bought?

Set each number's **SIP Endpoint (Primary)** in **DID Settings** on TelecomsXchange to the SBC's carrier side, for example `sip:14165551234@203.0.113.10:5060`, and assign the same number, with `+`, to a Teams user, resource account (auto attendant or call queue) as a Direct Routing number.

## How do I test it?

1. In Teams, call a number covered by the route from a user with the voice routing policy.
2. On the SBC, follow the call in its trace tool (AudioCodes Syslog Viewer or Wireshark; Ribbon's Monitoring and trace logs): the TLS INVITE from Teams with `+447700900123`, then the UDP INVITE to `80039#447700900123` (or `80039%23447700900123`) and TelecomsXchange's reply.
3. In the TelecomsXchange portal, watch the call in **Live Calls** and find its SIP code in **Logs → CDR (Voice)**.
4. In the **Teams admin center → Analytics & reports → PSTN usage report** (Direct Routing tab), and in Call Quality Dashboard, check the Teams leg.

## What if something goes wrong?

| You see | What to do |
|---|---|
| SBC shows inactive in the Teams admin center | TLS problem on the Teams side: certificate, FQDN not in a verified domain, or port 5061 blocked from Microsoft's ranges. This is between Teams and the SBC, not TelecomsXchange. |
| 401 or 407 repeated, then the call fails | The SBC isn't answering TelecomsXchange's challenge. Check the VoIP login and password in its account or authentication settings. |
| 403 Forbidden | The SBC's public IP isn't authorised and no credentials were sent. Compare with **IP Address** and **Additional Allowed IPs** on **Edit Account**; check balance. |
| 404 Not Found | Tech prefix missing or `+` still in the number. Check the outbound number manipulation in the SBC trace. |
| 408 or 503 from TelecomsXchange | The SBC can't reach sip01 on UDP 5060, or the route is blocked or failed. Check the firewall and **My Interconnections**. |
| One-way audio | The SBC advertises a private IP on the carrier side, or RTP from `174.136.44.213` is blocked. Check NAT and media settings on the carrier interface. |
| Inbound calls don't ring in Teams | No `+` on the number, the number isn't assigned with `-PhoneNumberType DirectRouting`, or `174.136.44.213` isn't classified to the TelecomsXchange peer. |

## References

- [Microsoft: Plan Direct Routing](https://learn.microsoft.com/en-us/microsoftteams/direct-routing-plan)
- [Microsoft: Connect your SBC to Direct Routing](https://learn.microsoft.com/en-us/microsoftteams/direct-routing-connect-the-sbc)
- [Microsoft: Configure call routing for Direct Routing](https://learn.microsoft.com/en-us/microsoftteams/direct-routing-voice-routing)
- [Microsoft: Enable users for Direct Routing](https://learn.microsoft.com/en-us/microsoftteams/direct-routing-enable-users)
- [Microsoft: Session border controllers certified for Direct Routing](https://learn.microsoft.com/en-us/microsoftteams/direct-routing-border-controllers)
- [Microsoft: New-CsOnlinePSTNGateway](https://learn.microsoft.com/en-us/powershell/module/teams/new-csonlinepstngateway)

## Frequently asked questions

**Q: Can Microsoft Teams register to TelecomsXchange?**

A: No. TelecomsXchange is peering only and does not accept REGISTER. Teams doesn't connect to carriers at all: it pairs with your SBC, and the SBC peers with TelecomsXchange by IP or digest authentication.

**Q: Can Teams connect to TelecomsXchange without an SBC?**

A: No. Direct Routing requires TLS for signalling and SRTP for media to a certified SBC with a public certificate. TelecomsXchange supports only SIP over UDP, so it can't be that endpoint.

**Q: Which SBC should I use?**

A: Any SBC on Microsoft's certified list for Direct Routing. AudioCodes Mediant and Ribbon SBC SWe are common; see the AudioCodes and Ribbon guides for the carrier-side settings.

**Q: Where does the tech prefix go?**

A: On the SBC, in the number manipulation for calls from Teams to TelecomsXchange. Teams sends +447700900123; the SBC sends 80039#447700900123 to sip01.