Source note · Early media and ringback behavior
In non-bypass Direct Routing, the SIP proxy replaces the client's SDP in the 183 Session Progress with the Media Processor's SDP, and the 183 is generated only once, either by the Ring Bot or a client endpoint, on an existing or new fork.
Checked 2026-09-24
- 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 · Multiple endpoints ringing with provisional answer, step 4
Cite this note
APA
WarmTransfer. (2026, September 24). Early media and ringback behavior: source note early-media-ringback-teams-183-mp-sdp. WarmTransfer. https://warmtransfer.net/knowledge/claims/early-media-ringback-teams-183-mp-sdp
BibTeX
@misc{warmtransfer-claim-early-media-ringback-teams-183-mp-sdp,
title = {Early media and ringback behavior: source note early-media-ringback-teams-183-mp-sdp},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/early-media-ringback-teams-183-mp-sdp},
note = {Source note early-media-ringback-teams-183-mp-sdp, checked 2026-09-24}
}