Cisco Unified Border Element Configuration Guide - Cisco IOS XE 17.6 Onwards: SIP Forking

Publisher

Cisco Systems

URL

https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/voice/cube/ios-xe/config/ios-xe-book/m_voi-cube-sip-rec-recorder.html

Published

2026-04-25

Updated

unknown

Accessed

2026-09-25

HTTP status

200

License

Cisco copyright; all rights reserved; no-redistribution; short excerpts and locators only

Source notes citing this source

• From IOS XE 17.18.2, if a recorder answers with an inactive SDP direction attribute, CUBE stops sending media packets to that recorder. in context
• CUBE does not support SIPREC recording of IPv6-to-IPv6 calls, nor of IPv6-to-IPv4 calls when the recording server is configured on the IPv6 leg. in context
• CUBE sends SIPREC metadata as XML that complies with draft-ietf-siprec-metadata-17, not with the final RFC 7865, and the metadata reflects session changes such as hold, transfer and escalation. in context
• Mid-call renegotiation and supplementary services such as hold and resume are not supported on the CUBE recorder call leg. in context
• CUBE does not support SIPREC recording of SRTP passthrough calls, SDP pass-through calls, flow-around calls or RTP loopback calls. in context
• IOS XE 17.18.1a improved CUBE SIP-recording serviceability so that it shows consolidated information on forked and associated anchor call legs. in context
• CUBE SIPREC sessions are verified with show voip recmsp session (including detail call-id and detail forked call-id variants), show voip rtp forking and show voip rtp connections. in context
• CUBE SIPREC recording is not supported for calls that do not use SIP; only SIP-to-SIP call flows are recorded. in context
• CUBE acts as the SIPREC Session Recording Client, in line with RFC 7245 section 3.1.1 (B2BUA as SRC), and forks a copy of the media to the recording server. in context
• For SRTP-to-RTP interworked calls, CUBE supports forking only from the RTP leg; forking from the SRTP leg is listed as a restriction. in context
• CUBE starts the recording session when the original call connects, and forks media after the recording server returns 200 OK. in context

Cite this source record

APA

WarmTransfer. (2026, April 25). Cisco Unified Border Element Configuration Guide - Cisco IOS XE 17.6 Onwards: SIP Forking. WarmTransfer. https://warmtransfer.net/knowledge/sources/cisco-cube-xe176-sip-forking

BibTeX

@misc{warmtransfer-cisco-cube-xe176-sip-forking,
  title  = {Cisco Unified Border Element Configuration Guide - Cisco IOS XE 17.6 Onwards: SIP Forking},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/sources/cisco-cube-xe176-sip-forking},
  note   = {Cisco Systems, accessed 2026-09-25}
}