Voice LabTeams Phone

Track 11

TLS, certificates, SIP

A dial-plan argument is wasted when the certificate name is wrong. OPTIONS tell you the trunk is alive.

Track sheetPNGPDF

Learn it in 5 minutes

You can walk a TLS failure, the three SIP proxies, and the codec list including the AMR-WB bypass limit.

Visual

Handshake before INVITETLS version · 1.2+Name · SAN matchesTrust · Public CAOPTIONS · 200 OK
Failure order. Counts in this drawing are teaching order, not customers.

Rooms

  1. The certificate profile 7 min
  2. Names, wildcards, and the paired FQDN 6 min
  3. Three SIP proxies and failover 7 min
  4. SIP OPTIONS 6 min
  5. Codecs and SRTP 7 min
  6. Failover you can rehearse 6 min

Ecosystem

CUCM

Cisco CUBE is one of the SBC families named in this lab’s certification lesson. A certified release can be the Direct Routing SBC between Unified CM and Teams.

The tenant still needs a verified domain on the SBC FQDN, and the user still needs Teams Phone. The studio translator does not open a live AXL session. Confirm the current certified release before you build.

Webex

Teams Phone and Webex Calling are separate clouds. This lab does not describe a feature that registers a Webex Calling user into a Teams tenant.

A number move is usually a carrier port, a certified SBC, or a meetings interop product. Confirm before relying.

UCCE

Unified CCE stays the ACD until you migrate it. Microsoft’s contact-center articles name Connect, Extend, and Unify. They do not name a UCCE connector in the notes this lab cites.

Voice into Teams is still Direct Routing or Operator Connect. The routing script stays on the contact-center product you bought. Confirm the vendor’s current model. Source: https://learn.microsoft.com/en-us/microsoftteams/teams-contact-center.

Sources and go deeper

Chapter list. Each room keeps its own sources.json.

  • Plan Direct Routing — Microsoft Learn — last checked 2026-10.
  • RFC 3261 — RFC — last checked 2026-10.
  • RFC 8446 — RFC — last checked 2026-10.
  • RFC 4566 — RFC — last checked 2026-10.
  • Transport Layer Security — Wikipedia — last checked 2026-10. Wikipedia fallback for background. Confirm the vendor page before you change a tenant
  • Session Initiation Protocol — Wikipedia — last checked 2026-10. Wikipedia fallback for background. Confirm the vendor page before you change a tenant
  • Microsoft Teams blog index — Community — last checked 2026-10. Community index for the Microsoft Teams blog. This is the index, not a claim that a post discusses this room

Room files: T11-R01-the-certificate-profile T11-R02-names-wildcards-and-the-paired-fqdn T11-R03-three-sip-proxies-and-failover T11-R04-sip-options T11-R05-codecs-and-srtp T11-R06-failover-you-can-rehearse