Microsoft's example of an SDES-only offer from Teams to an SBC lists AES_CM_128_HMAC_SHA1_32 as crypto tag 0 ahead of AES_CM_128_HMAC_SHA1_80 as tag 1, on an RTP/SAVP media line.

Checked 2026-09-23

Vendor
Microsoft
Product
Teams Phone Direct Routing
Subsystem
media bypass
Deployment
multi-tenant
Region
not restricted
Release range
current as of 2026-09-23
Checked
2026-09-23

Sources

Cite this note

APA

WarmTransfer. (2026, September 23). SRTP and media encryption negotiation: source note srtp-media-security-teams-offer-sha1-32-first. WarmTransfer. https://warmtransfer.net/knowledge/claims/srtp-media-security-teams-offer-sha1-32-first

BibTeX

@misc{warmtransfer-claim-srtp-media-security-teams-offer-sha1-32-first,
  title  = {SRTP and media encryption negotiation: source note srtp-media-security-teams-offer-sha1-32-first},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/claims/srtp-media-security-teams-offer-sha1-32-first},
  note   = {Source note srtp-media-security-teams-offer-sha1-32-first, checked 2026-09-23}
}

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