AMR‑WB codec support added to Teams Direct Routing SIP interface

Microsoft Teams Direct Routing will support the AMR-WB codec starting early March 2026, enhancing audio quality in non-media-bypass SIP calls. This automatic update affects organizations using Teams Direct Routing and SBCs, with no required configuration changes. SBC admins should verify AMR-WB support and update documentation accordingly.

[Introduction]

Microsoft will add support for the Adaptive Multi‑Rate Wideband (AMR‑WB) codec to improve audio quality for calls placed through Teams Direct Routing. This enhancement will introduce wideband audio capabilities when supported by your Session Border Controller (SBC) and will apply to non‑media‑bypass scenarios where the Session Initiation Protocol (SIP) interface negotiates codecs with the Teams service.

[When this will happen]

• General Availability (Worldwide): Rollout will begin in early March 2026 and is expected to complete by mid‑March 2026.

[How this affects your organization]

Who is affected:

• Organizations using Teams Direct Routing for PSTN connectivity.
• SBC administrators managing non‑media‑bypass SIP call flows with the Teams SIP interface.

What will happen:

• Outbound calls from Teams to the SBC will include AMR‑WB and DTMF/1600 in the codec offer.
• Inbound calls from the SBC will prefer and select AMR‑WB when the SBC includes it in the offer.
• AMR‑WB support will be enabled automatically; no configuration changes will be required in the Teams admin center.
• Existing codecs (such as SILK and G.711) will remain supported; this is an additive enhancement.

[What you can do to prepare]

Most organizations will not need to take action.

Recommended steps for SBC administrators:

• Verify that your SBC software version supports AMR‑WB.
• Review SBC vendor documentation to ensure AMR‑WB is enabled or allowed in your configuration.
• Communicate the upcoming codec support to your helpdesk, if they support Teams Phone or Direct Routing.
• Update internal documentation or topology diagrams if you track codec behavior for call flows.
• For technical details, review What's new for Direct Routing | Microsoft Teams | Microsoft Learn.

[Compliance considerations]

No compliance considerations identified. Review as appropriate for your organization.