3 Definitions, symbols and abbreviations
23.2313GPPRelease 17SIP-I based circuit-switched core networkStage 2TS
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].
3.2 Symbols
For the purposes of the present document, the following symbols apply:
Iu Interface between the RNS and the core network. It is also considered as a reference point.
Mc Interface between the server and the media gateway.
Nb Interface between media gateways.
Nc The NNI call control interface between (G)MSC servers.
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].
BCF Bearer Control Function
BICC Bearer Independent Call Control
BICN Bearer Independent Core Network
CS Circuit Switched
DSP Digital Signal Processing
GERAN GSM/EDGE Radio Access Network
(G)MSC-S (Gateway) MSC Server
IAM Initial Address Message
IETF Internet Engineering Task Force
IP Internet Protocol
IPBCP IP Bearer Control Protocol
IWF Interworking Function
LCLS Local Call Local Switch
MGCF Media Gateway Control Function
MGW Media Gateway
MSC-S MSC Server
MSC/IWF IWF at call control layer toward external network (see 3GPP TS 29.007 [6])
NNI Network-Network interface
OoBTC Out of Band Transcoder Control
PRACK Provisional Response Acknowledgement
RTO Remote Transcoder Operation
RTP Real-Time Transport Protocol
SCTP Stream Control Transmission Protocol
SCUDIF Service Change and UDI Fallback
SIP Session Initiation Protocol
SDP Session Description Protocol
TCP Transmission Control Protocol
TDM Time-Division Multiplexing
TFO Tandem Free Operation
TrFO Transcoder Free Operation
UDP User Datagram Protocol
UTRAN UMTS Terrestrial Radio Access Network