SIP trunk pieces

Sources and go deeper

Opened 2026-10. A row marked confirm has no link, because that page was not verified.

RFC. RFC 3261, SIP last checked 2026-10
RFC. RFC 4028, SIP session timers last checked 2026-10
Cisco. Cisco Unified Communications Manager product support last checked 2026-10
Cisco. System Configuration Guide for CUCM, Release 15 last checked 2026-10
Protocol and ports. CUCM 15 TCP and UDP port usage last checked 2026-10
Protocol and ports. IANA SIP parameters last checked 2026-10
Community. Cisco Community, Collaboration knowledge base last checked 2026-10
Wikipedia. Session Initiation Protocol (Wikipedia) last checked 2026-10
Cisco. Collaboration 12 SRND book. confirm. The historical Collaboration 12 SRND path opened as a product listing, not the design book. Use the Preferred Architecture index, which was opened. last checked 2026-10