3 Definitions and abbreviations

24.3223GPPRelease 17Stage 3TSTunnelling of IP Multimedia Subsystem (IMS) services over restrictive access networks

3.1 Definitions

For the purposes of the present document, the terms and definitions given in 3GPP TR 21.905 [1] and the following apply.
A term defined in the present document takes precedence over the definition of the same term, if any, in 3GPP TR 21.905 [1].

Firewall traversal tunnel to IP network of IMS: a TCP connection with TLS connection enabling passing of envelopes between UE in restrictive non-3GPP access network and EFTF, established in order to reach IP network of IP multimedia core network subsystem.

For the purposes of the present document, the following terms and definitions given in 3GPP TS 24.229 [2] apply:

IP multimedia core network subsystem

For the purposes of the present document, the following terms and definitions given in 3GPP TS 24.302 [3] apply:

Restrictive non-3GPP access network type I

Restrictive non-3GPP access network type II

Restrictive non-3GPP access network

For the purposes of the present document, the following terms and definitions given in 3GPP TS 33.203 [4] apply:

Enhanced firewall traversal function

3.2 Abbreviations

For the purposes of the present document, the abbreviations given in 3GPP TR 21.905 [1] and the following apply. An abbreviation defined in the present document takes precedence over the definition of the same abbreviation, if any, in 3GPP TR 21.905 [1].

EFTF Enhanced firewall traversal function

FTT-IMS Firewall traversal tunnel to IP network of IMS

HTTP Hypertext transfer protocol

IMS IP multimedia core network subsystem

TCP Transmission control protocol

TLS Transport layer security

URI Uniform resource identifier