Source note · Early media and ringback behavior

In Teams Direct Routing, a Teams endpoint's Call progress is converted by the SIP proxy into a 180 message, and on receiving 180 the SBC must generate local ringing.

Checked 2026-09-24

On receiving message 180, the SBC must generate local ringing.

Vendor: Microsoft
Product: Teams Phone Direct Routing
Subsystem: SIP proxy inbound call dialog
Deployment: multi-tenant
Region: not restricted
Release range: current as of 2026-09-24
Checked: 2026-09-24

Sources

Teams Phone System Direct Routing: SIP protocol — Microsoft · tier 2 current vendor documentation · Inbound call: SIP dialog description > Non-media bypass flow

Cite this note

APA

WarmTransfer. (2026, September 24). Early media and ringback behavior: source note early-media-ringback-teams-180-local-ring. WarmTransfer. https://warmtransfer.net/knowledge/claims/early-media-ringback-teams-180-local-ring

BibTeX

@misc{warmtransfer-claim-early-media-ringback-teams-180-local-ring,
  title  = {Early media and ringback behavior: source note early-media-ringback-teams-180-local-ring},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/claims/early-media-ringback-teams-180-local-ring},
  note   = {Source note early-media-ringback-teams-180-local-ring, checked 2026-09-24}
}

Read in context