Cisco Collaboration System 12.x Solution Reference Network Designs (SRND) - Cisco Unified CM Trunks

Publisher

Cisco

URL

https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/srnd/collab12/collab12/trunks.html

Published

unknown

Updated

unknown

Accessed

2026-09-24

HTTP status

200

License

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

Source notes citing this source

• When the trunk runs on all active nodes, CUBE should trust and target every call-processing subscriber, because any of them may originate calls and trusted-list failures are silently dropped. inferred in context
• With Run on all Active Unified CM Nodes checked, Unified CM runs a SIP trunk instance on every call-processing subscriber, so trunk calls can be made or received on any of them. in context
• Cisco's 12.x SRND recommends Early Offer support for voice and video calls set to Best Effort (no MTP inserted) for all Unified CM and Session Management Edition SIP trunks. in context
• With Early Offer set to Mandatory (insert MTP if needed), Unified CM inserts an MTP when it cannot determine the calling device's media characteristics; Best Effort sends Delayed Offer in that case. in context
• Cisco's 12.x SRND recommends enabling SIP OPTIONS ping on all SIP trunks so Unified CM tracks trunk state dynamically instead of per call on timeout. in context

Cite this source record

APA

WarmTransfer. (2026, September 24). Cisco Collaboration System 12.x Solution Reference Network Designs (SRND) - Cisco Unified CM Trunks. WarmTransfer. https://warmtransfer.net/knowledge/sources/cisco-srnd-collab12-trunks

BibTeX

@misc{warmtransfer-cisco-srnd-collab12-trunks,
  title  = {Cisco Collaboration System 12.x Solution Reference Network Designs (SRND) - Cisco Unified CM Trunks},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/sources/cisco-srnd-collab12-trunks},
  note   = {Cisco, accessed 2026-09-24}
}