3 Definitions and abbreviations

24.6283GPPCommon Basic Communication procedures using IP Multimedia (IM) Core Network (CN) subsystemProtocol specificationRelease 17TS

3.1 Definitions

For the purposes of the present document, the following terms and definitions apply:

announcement: service related message sent to a user that can be of any type of media e.g. a voice message or a
video-clip

communication: transfer of information between two or more users, entities, processes or nodes according to some agreed conventions

NOTE: See ITU-T Recommendation I.112 modified [11].

early media: media sent before a communication is established

in-band announcement: announcement sent by the network using the bearer established for a communication

Originating Application Server (O-AS): controlling application server responsible for the services provided to the originating user

Terminating Application Server (T-AS): controlling application server responsible for the services provided to the terminating user

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

3pcc 3rd party call control

ACR Automatic Call Rejection

AS Application Server

B2BUA Back-to-Back User Agent

IFC Initial Filter Criteria

IMS IP Multimedia Subsystem

ISDN Integrated Services Digital Network

MGCF Media Gateway Control Function

MGW Media GateWay

MRFC Media Resource Function Controller

MRFP Media Resource Function Processors

NDUB Network Determined User Busy

O-AS Originating Application Server

P-CSCF Proxy Call Session Control Function

PSTN Public Switched Telephone Network

S-CSCF Serving Call Session Control Function

SDP Session Description Protocol

SIP Session Initiation Protocol

T-AS Terminating Application Server

T-MGF Trunking Media Gateway Function

UDUB User Determined User Busy

UE User Equipment

URL Uniform Resource Locator