Digital cellular telecommunications system (Phase 2+); Universal Mobile Telecommunications System (UMTS); LTE; IP Multimedia (IM) Subsystem Cx and Dx Interfaces; Signalling flows and message contents (V7.14.0; 3GPP TS 29.228 version 7.14.0 Release 7; Incl
This 3GPP Technical Specification (TS) specifies: 1. The interactions between the HSS (Home Subscriber Server) and the CSCF (Call Session Control Functions)@ referred to as the Cx interface. 2. The interactions between the CSCF and the SLF (Server Locator Function)@ referred to as the Dx interface. The IP Multimedia (IM) Subsystem stage 2 is specified in 3GPP TS 23.228 [1] and the signalling flows for the IP multimedia call control based on SIP and SDP are specified in 3GPP TS 24.228 [2]. This document addresses the signalling flows for Cx and Dx interfaces. This document also addresses how the functionality of Px interface is accomplished. The Presence Service Stage 2 description (architecture and functional solution) is specified in 3GPP TS 23.141 [10].