1. Configuration Guide
  2. Session Plug-In Language
  3. Enterprise SPLs
  4. SIP Trunking SPLs for Specific Service Providers
  5. Surrogate Registration

Surrogate Registration

When interoperating with KDDI or NTT trunks, use the following spl-options to support this surrogate registration function:
  • dyn-contact-start—Configure on the sip-interface facing the CUCM realm.
  • dyn-contact-method=randomseed—Configure on the sip-interface facing the NTT or KDDI trunk.

When configured, the ESBC:

  • Sends the IP address of the egress sip-interface in the host part of the Call-ID within SIP INVITE requests to NTT or KDDI.
  • Removes the string “sbc” from the host part of the Call-ID while sending out de-REGISTER requests.
  • Adds the egress sip-interface IP address to the host part of the call-id.
  • Sends two de-REGISTERs messages with at least a 1 second interval for the same AOR.

SPL functions persist after a reboot.