5G • Services
P-CSCF
Proxy Call Session Control Function
First contact point within IMS terminating user SIP signaling and interfacing to 5GC PCF via Rx/N5.
Technical Explanation
The P-CSCF terminates the SIP signaling link from the smartphone. It inspects Session Description Protocol (SDP) media attributes, authorizes codecs, and communicates with the 5G Core PCF across the Rx or N5 interface to dynamically trigger dedicated 5QI 1 GBR voice bearer setup.
Key Functions
- First contact point for UE SIP signaling in the IP Multimedia Subsystem
- Terminates client IPsec signaling security association
- Triggers dynamic 5QI 1 voice bearer setup via N5/Rx interface to PCF
Specifications
3GPP TS 23.228, TS 29.514
Interfaces
GmMwN5Rx
Related 5G Concepts
Want to memorize 5G concepts like this one?
Study it with SuperMemo SM-2 spaced repetition flashcards.