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TLS names, trust anchors, and version

Handshake failures stay below SIP. A Teams 403 is the Contact FQDN rule after TLS is up.

Learn in 5 minutes

  1. Separate handshake failures from SIP status codes
  2. Require TLS 1.2 or newer toward Teams
  3. Put an FQDN in Contact or expect 403

Visual

OPTIONS to Teams after TLS · study drawing · cyphermonkeylabs.com CUBETeams OPTIONS 200 INVITE 100

SVG HTML PNG

The first three stop before a SIP status. The fourth is SIP.

Worked example

Find the FQDN Inspect the INVITE Contact. What hostname is in it, and what would a bare address draw?

  1. Press Play.
  2. Step until the hop named in the question.
  3. Inspect that message and answer the check.

Fault

INVITE to sip.pstnhub.microsoft.com returns 403. The certificate chain validated and the handshake used TLS 1.2.

A SIP 403 means the request arrived. Handshake failures do not produce that status.

Quiz

A certificate name mismatch shows up as


Teams Direct Routing TLS version in this lesson is


An IP address in Contact toward Teams draws


An untrusted CA fails


The synthetic Teams target named here is


OPTIONS in this flow proves


Ecosystem

Glossary, sister systems, and the integration seam for this room.

AI omni-channel agents A voice bot still needs a session. SIP creates, modifies, and ends sessions. Omni-channel, in the contact-center sense, means the same contact can also live on chat or another digital channel. Those channels do not replace the voice session. On Amazon Connect the platform owns the managed PSTN voice channel. Bridging an outside carrier into Connect with a Chime Voice Connector is not a supported pattern unless AWS reviews it. When an SBC forks the voice leg to a recorder, that fork is SIPREC, a different plane from the customer dialog.

AI agents A voice bot still needs a session. On Amazon Connect the platform owns the managed PSTN voice channel. Bridging an outside carrier into Connect with a Chime Voice Connector is not a supported pattern unless AWS reviews it. The FreeSWITCH manual page also describes SignalWire, founded by the FreeSWITCH team, as a hosted platform with AI agents behind REST APIs and SWML.

Glossary · Ecosystem map · Ports · Troubleshooting

Sources and go deeper