For the purposes of the present document, the terms and definitions given in
TR 21.905 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.
Anchoring in IMS:
Insertion of the Domain Transfer Function in the signalling path of the voice call/session establishment in order to enable the capability of domain transfer for this call/session.
IP Multimedia Routing Number (IMRN):
An IMRN is a routable number that points to the IM CN subsystem. In a roaming scenario, the IMRN has the same structure as an international ISDN number. The Tel URI format of the IMRN is treated as a PSI within the IM CN subsystem.
CS Domain Routing Number (CSRN):
A CSRN is a number that is used to route a call from the IM CN subsystem to the user in the CS domain.
Domain Transfer:
Transfer of the access leg of a voice call on a UE from CS domain to IMS and vice versa while maintaining active session.
Access Leg:
This is the call control leg between the VCC UE and the DTF.
Remote Leg:
This is the call control leg between the DTF and the remote party from the VCC subscriber's perspective.
VCC UE:
User Equipment supporting the VCC feature. The VCC UE is defined in
clause 5.3.2 of this document.
VCC Domain Transfer Number (VDN):
A public telecommunication number, as defined by ITU-T Recommendation E.164 [16] used by the UE to request the DTF to perform Domain Transfer to the CS domain from the IMS.
VCC Domain Transfer URI (VDI):
A SIP URI used by the UE to request the DTF to perform Domain Transfer to the IMS from the CS domain.
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.
3pcc
Third party call control
CSAF
CS Adaptation Function
CSRN
CS Domain Routing Number
DSF
Domain Selection Function
DTF
Domain Transfer Function
iFC
Initial Filter Criteria
IMRN
IP Multimedia Routing Number
PSI
Public Service Identity
VCC
Voice Call Continuity
VDI
VCC Domain Transfer URI
VDN
VCC Domain Transfer Number