With voice-class codec transparent, CUBE passes only the offer unfiltered; it still filters SDP in the answer, and Cisco describes only the first codec of the offer list being included in the outbound message.

Checked 2026-09-25

Codec filtering is carried out on SDP content in ANSWER messages.
Vendor
Cisco
Product
CUBE
Subsystem
codec transparent
Deployment
on-premises
Region
not restricted
Release range
IOS XE 17.6 onwards
Checked
2026-09-25

Sources

Cite this note

APA

WarmTransfer. (2026, September 25). SIP 488 and codec negotiation failures: source note sip-488-codec-failures-cube-codec-transparent. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-488-codec-failures-cube-codec-transparent

BibTeX

@misc{warmtransfer-claim-sip-488-codec-failures-cube-codec-transparent,
  title  = {SIP 488 and codec negotiation failures: source note sip-488-codec-failures-cube-codec-transparent},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/claims/sip-488-codec-failures-cube-codec-transparent},
  note   = {Source note sip-488-codec-failures-cube-codec-transparent, checked 2026-09-25}
}

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