U.4 3GPP specific encoding for SIP header field extensions

U.2A Usage of SDP

T.2 Application of network policy for the support of transcoding

T.1 Scope

U.2 IP-CAN aspects when connected to the IM CN subsystem

U.1 Scope

S.3 Application usage of SIP

S.2A Usage of SDP

S.5 Use of circuit-switched domain

S.4 3GPP specific encoding for SIP header field extensions