24.6423GPPCompletion of Communications to Busy Subscriber (CCBS) and Completion of Communications by No Reply (CCNR) using IP Multimedia (IM) Core Network (CN) subsystemProtocol specificationRelease 16TS
For the purposes of the present document, the terms and definitions given in 3GPP TS 22.173  and the following terms and definitions apply.
busy: See ITU-T Recommendation I.221 , subclause 2.1.5.
call information retention: A procedure of network A to store the call information of a specific call so that it can be used for that call.
caller: The user who originated the call and to whom the CCBS service is provided.
callee: The user which is identified as destination B.
CC: Completion of Communication
CC busy: Any one of the following conditions will cause a CCBS busy condition:
– maximum number of calls reached at user A (see ITU-T Recommendation I.221 , subclause 2.1.3, item 2));
– no resources (bandwidth) available at user A;
– CC recall pending on user A.
CC call: A call generated by the network connecting the caller to the callee, resulting from the callers’ acceptance of a CC recall.
CC recall: An indication informing the caller that the network is ready to initiate a CC call to the callee and that the network is awaiting a response to this indication.
CC request: An instance of an activation of the CCBS/CCNR/CCNL service which is held in a queue pending the correct conditions for the CCBS/CCNR/CCNL service to be completed.
Suspended CC request: A CC request which cannot be served even if the callee is in the appropriate state because the caller is busy.
CC request retention: If an attempt to establish a CC call fails because the destination is busy again, then the network provider option "CC request retention" defines whether the CC supplementary service is continued or not, i.e. if the "CC request retention" is supported, the original CC request retains its position in the queue B, and monitoring of user B shall continue. Otherwise the CC request is revoked.
CC service duration timer: A maximum time a CC service will remain activated for the caller within the network.
destination B: The entity addressed in the original call.
long-term denial: The network cannot accept user A’s request to activate the CC service and a later attempt to activate the CC service for the same destination B will also be rejected.
queue A: A buffer at the originating side for the control of CC requests associated with the caller.
queue B: A buffer at the terminating side for the control of CC requests associated with destination B.
retain option: The retain option, if supported in both the originating and destination network, will maintain the CC request in the destination B queue, if a CC call has failed due to destination busy condition.
short-term denial: The network temporarily cannot accept user A’s request to activate the CC service. A later attempt to activate the CC service for the same destination B may succeed.
UE-A: The caller’s UE.
UE-B: The callee’s UE.
For the purposes of the present document, the following abbreviations apply:
AOC Advice Of Charge
AS Application Server
CB Communication Barring
CC Completion of Communications
CCBS Completion of Communications to Busy Subscriber
CCNL Completion of Communications on Not Logged-in
CCNR Completion of Communications on No Reply
CD Communication Deflection
CDIV Call DIVersion
CFB Communication Forwarding Busy
CFNL Communication Forwarding on No Logged-in
CFU Communication Forwarding Unconditional
CN Core Network
CNR Completion of communication on No Reply
CONF CONFerence calling
CS Circuit Switched
CW Communication Waiting
ECT Explicit Communication Transfer
HOLD Communication Hold
IFC Initial Filter Criteria
IM IP Multimedia
IMS IP Multimedia Subsystem
IP Internet Protocol
ISDN Integrated Service Data Network
MCID Malicious Communication IDentification
MIME Multipurpose Internet Mail Extensions
OIP Originating Identification Presentation
OIR Originating Identification Restriction
PLMN Public Land Mobile Network
PSTN Public Switch Telephone Network
SIP Session Initiation Protocol
TIP Terminating Identification Presentation
TIR Terminating Identification Restriction
UE User Equipment