Source note · Early media and ringback behavior

From IOS XE Denali 16.3.1, if the inbound leg does not support PRACK or UPDATE, CUBE by default consumes multiple forked 18x responses with SDP received during the early dialog.

Checked 2026-09-24

Vendor: Cisco
Product: Cisco Unified Border Element
Subsystem: early dialog forking
Deployment: on-premises
Region: not restricted
Release range: IOS XE Denali 16.3.1 onwards
Checked: 2026-09-24

Sources

Cisco Unified Border Element Configuration Guide: Consumption of Forked 18x Responses with SDP During Early Dialog — Cisco Systems · tier 2 current vendor documentation · Consumption of Forked 18x Responses with SDP During Early Dialog > information and feature history

Cite this note

APA

WarmTransfer. (2026, September 24). Early media and ringback behavior: source note early-media-ringback-cube-forked-18x. WarmTransfer. https://warmtransfer.net/knowledge/claims/early-media-ringback-cube-forked-18x

BibTeX

@misc{warmtransfer-claim-early-media-ringback-cube-forked-18x,
  title  = {Early media and ringback behavior: source note early-media-ringback-cube-forked-18x},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/claims/early-media-ringback-cube-forked-18x},
  note   = {Source note early-media-ringback-cube-forked-18x, checked 2026-09-24}
}

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