SIP trunk to another PBX

Sources and go deeper

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

Wikipedia. SIP trunking (Wikipedia) last checked 2026-10
SIP Forum. SIPconnect technical recommendation last checked 2026-10
RFC. RFC 3261, SIP 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