A.1 Scope of signalling flows

24.1823GPPIP Multimedia Subsystem (IMS) Customized Alerting Tones (CAT)Protocol specificationRelease 17TS

Tools: ARFCN - Frequency Conversion for 5G NR/LTE/UMTS/GSM

This annex gives examples of signalling flows for the CAT service within the IP Multimedia (IM) Core Network (CN) subsystem based on the Session Initiation Protocol (SIP).