Covid 19 Update: Given the current global situation, we have paused the delivery of our LiveOnsite courses, but our LiveOnline and OnlineAnytime Packages remain unaffected. Browse over 50 online courses in our course catalogue, or get in touch to register your interest in future LiveOnsite courses when we are able to safely resume in person training.

ICID - IM CN subsystem Charging Identifier

The ICID is used within the IMS (IP Multimedia Subsystem) to correlate session level charging information in both the visited and home networks. It is generated at the edge of the IMS, either by the P-CSCF (Proxy – Call Session Control Function) in the case of MO (Mobile Originated) sessions and the I-CSCF (Interrogating – Call Session Control Function) for MT (Mobile Terminated) sessions. All subsequent billable events for the session are associated with this identifier.


  • Fully interactive 3GPP based network map
  • Narrated call flows
  • Detailed network procedures

Explore NetX today with a
free trial.
More Info about NetX