This TS specifies:
The interactions between the HSS (Home Subscriber Server) and the SIP AS (Application Server) and
between the HSS and the OSA SCS (Service Capability Server). This interface is referred to as the Sh
The interactions between the SIP AS and the SLF (Subscription Locator Function) and between the OSA SCS
and the SLF. This interface is referred to as the Dh reference point.
This document addresses the signalling flows and message contents for the protocol at the Sh
This document also addresses how the functionality of Ph
interface is accomplished.
The Presence Service Stage 2 description (architecture and functional solution) is specified in TS 23.141