Source note · SIP 488 and codec negotiation failures
Microsoft's example SDES-only offer from Teams to the SBC carries two crypto lines, AES_CM_128_HMAC_SHA1_32 and AES_CM_128_HMAC_SHA1_80, on an RTP/SAVP m= line.
Checked 2026-09-25
- Vendor
- Microsoft
- Product
- Teams Phone Direct Routing
- Subsystem
- SRTP
- Deployment
- multi-tenant
- Region
- not restricted
- Release range
- current as of 2026-09-25
- Checked
- 2026-09-25
Sources
- Direct Routing support for media bypass - Microsoft Teams — Microsoft Learn · tier 2 current vendor documentation · Section Format for SDES only offer to SBC (example block)
Cite this note
APA
WarmTransfer. (2026, September 25). SIP 488 and codec negotiation failures: source note sip-488-codec-failures-teams-offer-two-crypto. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-488-codec-failures-teams-offer-two-crypto
BibTeX
@misc{warmtransfer-claim-sip-488-codec-failures-teams-offer-two-crypto,
title = {SIP 488 and codec negotiation failures: source note sip-488-codec-failures-teams-offer-two-crypto},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/sip-488-codec-failures-teams-offer-two-crypto},
note = {Source note sip-488-codec-failures-teams-offer-two-crypto, checked 2026-09-25}
}