11 · TLS, certificates, SIP
An empty codec list is a 488. Missing media ports is silence after a 200.
Direct Routing lists SILK, G.711, G.722, G.729, and AMR-WB for non-bypass calls. Offer a codec both sides have. G.711 µ-law and A-law both belong if the carrier is vague. Media is SRTP. A trunk that offers only plaintext RTP is not the design.
DTMF has to survive every hop or the IVR never hears 1. Test digits through the carrier, not only Teams-to-Teams. If bypass is on, do not depend on AMR-WB.
Agree a codec, keep SRTP, and prove DTMF through the SBC. AMR-WB is not a bypass codec.
I offer G.711, I use SRTP, and I test DTMF through the carrier.
If it fails: The SBC allows only a codec Teams will not use on that path, and every call is 488.
Which description of SIP options timer teaching model is accurate?
This campus treats repeated missed OPTIONS as a reason to pull a trunk. It does not publish Microsoft’s internal counter as if it were a documented integer. A lab timer is not a contractual timer. Source: https://learn.microsoft.com/en-us/microsoftteams/direct-routing-plan accessed 2026-10-14.
A colleague reports: Someone sets a script to fail over after one missed packet and flaps the trunk. Where do you start?
Someone sets a script to fail over after one missed packet and flaps the trunk. Watch the admin-center SBC status and the SBC’s own OPTIONS log together. Source: https://learn.microsoft.com/en-us/microsoftteams/direct-routing-plan accessed 2026-10-14.
Which description of Failover rehearsal is accurate?
Pull the primary proxy or the primary SBC in a window and prove the next one takes calls. A second gateway that has never received a call is a drawing. Source: https://learn.microsoft.com/en-us/microsoftteams/direct-routing-plan accessed 2026-10-14.
Around the call: compliance recording, workforce management, emergency location, analytics, CRM screen pop, and an agent with a human escape. Each one has its own failure.
The SBC allows only a codec Teams will not use on that path, and every call is 488.
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.
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.
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.
Copilot Studio, Azure Communication Services, and Graph are later tracks in this lab. Treat any uncited limit as confirm before relying.
Opened 2026-10. A row marked confirm did not open. Wikipedia is background. The Teams blog row is the community index.
