3 Definitions, symbols and abbreviations

23.3343GPPIP Multimedia Subsystem (IMS) Application Level Gateway (IMS-ALG) - IMS Access Gateway (IMS-AGW) interface: Procedures descriptionsRelease 17TS

3.1 Definitions

For the purposes of the present document, the terms and definitions given in 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 TR 21.905 [1].

End-to-access edge security: media protection extending between an IMS UE and the first IMS core network node in the media path without being terminated by any intermediary node.

End-to-end security: media protection between two IMS UEs without being terminated by any intermediary node.

Full ICE: The full implementation of the Interactive Connectivity Establishment (ICE) specified in IETF RFC 8445 [82].

ICE lite: The lite implementation of the Interactive Connectivity Establishment (ICE) specified in IETF RFC 8445 [82].

Local (near-end) NAPT control: the operation of providing network address mapping information and NAPT policy rules to a near-end NAT in the media flow.

NAT-PT/NAPT-PT: see definition in 3GPP TS 23.228 [2].

NAPT control and NAT traversal: controls network address translation for both near-end NA(P)T and far-end NA(P)T

Network Address Translation (NA(P)T): see definition in 3GPP TS 23.228 [2].

Remote (far-end) NAT traversal: the operation of adapting the IP addresses so that the packets in the media flow can pass through a far-end (remote) NAT.

RTP / RTCP transport multiplexing: a single IP transport (L4) port for RTP and RTCP packets.

TLS-client: the entity that initiates a TLS session establishment to a server.

TLS-server: the entity that responds to requests for TLS session establishment from clients.

TLS endpoint: either a TLS-client or a TLS-server.

Convention:

Wherever the term NAT is used in this specification, it may be replaced by NA(P)T or NA(P)T-PT.

For the purposes of the present document, the following terms and definitions given in 3GPP TS 23.237 [18] apply:

Access Leg

Access Transfer Control Function (ATCF)

Access Transfer Gateway (ATGW)

Remote Leg

Target Access Leg

Source Access Leg

3.2 Symbols

For the purposes of the present document, the following symbols apply:

Iq Interface between the IMS Application Level Gateway and the IMS Access Media Gateway

3.3 Abbreviations

For the purposes of the present document, the abbreviations given in 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 TR 21.905 [1].

ALTC Alternate Connectivity

AMR Adaptive Multi-Rate

AMR-WB Adaptive Multi-Rate – WideBand

AMR-WB IO Adaptive Multi-Rate – WideBand Inter-operable Mode, included in the EVS codec

APP APPlication-defined RTCP packet

ATCF Access Transfer Control Function

ATGW Access Transfer Gateway

BFCP Binary Floor Control Protocol

CCM Codec Control Messages

CVO Coordination of Video Orientation

DBI Delay Budget Information

DC Data Channel

DTLS Datagram Transport Layer Security

DTX Discontinuous Transmission

e2ae security End-to-access-edge security

e2e security End-to-end security

ECN Explicit Congestion Notification

ECN-CE ECN Congestion Experienced

eIMS-AGW IMS Access Gateway enhanced for WebRTC

eP-CSCF P-CSCF enhanced for WebRTC

EVS Enhanced Voice Services

FECC Far End Camera Control

FIR Full Intra Request

GTT Global Text Telephony

ICE Interactive Connectivity Establishment

IMS-AGW IMS Access Media Gateway

IMS-ALG IMS Application Level Gateway

IM CN IMS Core Network

MSRP Message Session Relay Protocol

MTSI Multimedia Telephony Service for IMS

NA(P)T Network Address and optional Port Translation

NAPT Network Address Port Translation

NAT Network Address Translation

NA(P)T-PT NAT Address (and optional Port-) Translation and Protocol Translation

P-CSCF Proxy-CSCF

ROI Region of Interest

RTCP RTP Control Protocol

RTP Real-time Transport Protocol

SDPCapNeg SDP Capability Negotiation

SRTP Secure Real-time Transport Protocol

SRVCC Single Radio Voice Call Continuity

STUN Session Traversal Utilities for NAT

TLS Transport Layer Security

TMMBN Temporary Maximum Media Stream Bit Rate Notification

TMMBR Temporary Maximum Media Stream Bit Rate Request

TURN Traversal Using Relay NAT

UDPTL User Datagram Protocol Transport Layer

URN Uniform Resource Name

WebRTC Web Real-Time Communication

WIC WebRTC IMS Client

WWSF WebRTC Web Server Function