For the purposes of the present document, the terms and definitions given in
TR 21.905 and the following apply:
ICE lite:
The lite implementation of the Interactive Connectivity Establishment (ICE) specified in IETF
RFC 8445.
Full ICE:
The full implementation of the Interactive Connectivity Establishment (ICE) specified in IETF
RFC 8445.
Interworking Unit (IWU):
Logical entity that interworks SIP-I signalling in the 3GPP CS Domain with any of the following signalling: (a) SIP-I signalling of an external SIP-I network, (b) ISUP signalling of a PSTN, and (c) BICC or ISUP signalling of a 3GPP CS Domain.
User Plane Interworking Unit (UP-IWU):
Logical entity that performs user plane interworking between the SIP-I based CS Domain and an external SIP-I network, or external ISUP network, or BICC/ISUP based 3GPP CS network.
For the purposes of the present document, the abbreviations given in
TR 21.905 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.
ALG
Application Level Gateway
ANM
ANswer Message
APM
Application Transport Mechanism
B2BUA
(SIP) Back-to-Back User Agent
BGCF
Breakout Gateway Control Function
BICC
Bearer Independent Call Control
CON
Connect message
COT
Continuity message
CPG
Call ProGress message
CS-IBCF
CS (domain) IBCF
CS-TrGW
CS (domain) TrGW
IBCF
Interconnection Border Control Function
ICE
Interactive Connectivity Establishment
ITU-T
International Telecommunication Union - Telecommunication Standardization Sector
IM-MGW
IP Multimedia Media Gateway Function
IW-MSC
Interworking MSC
MIME
Multi-purpose Internet Mail Extensions
MRFP
Multimedia Resource Function Processor
NA(P)T
Network Address Translation / Network Address and Port Translation
NNI
Network to Network Interface
O-MSC
Originating MSC
OoB
Out of Band
OoBTC
Out of Band Transcoder Control
RES
RESume
RLC
Release Complete
SCTP
Stream Control Transmission Protocol
SDPCapNeg
SDP Capability Negotiation
SIP-I
SIP with encapsulated ISUP
STUN
Session Traversal Utilities for NAT
SUS
SUSpend
TDM
Time-Division Multiplexing
THIG
Topology Hiding Internetwork Gateway
TMR
Transmission Medium Requirement
TrGW
Transition Gateway
UA
(SIP) User Agent
UP-IWU
User Plane Interworking Unit
USI
User Service Information