A.1 Normal cases

24.4043GPPProtocol specificationPSTN/ISDN simulation services: Communication Diversion (CDIV)Release 7TISPANTS

A.1.1 Communication Forwarding unconditional

Figure A.1: CFU AS based normal case

User B has activated the CFU service.

User A is sending a communication request towards User B:

1 to 2) Initial INVITE request towards user B. The URI-B is subscribed to the CFU service.

3 to 4) The based on the IFC the INVITE is forwarded to the AS.

5) Procedures for CFU are executed.

6 to 8) A 181 may be sent towards the User A indicating that the communication is diverted.

9) A Invite including URI-C as destination is sent back to the S-CSCF. Additional the History Header is included.
History-Info: <sip:User-B@example.com>;index=1,
<sip:User-C@example.com;;cause=302>index=1.1.

10) S-CSCF looks up to the HSS to identify the location of User-C.

11 to 12) The communication is routed towards User-C.

13 to 18) The 200 OK is sent Back to the User-A.

19 to 24) The ACK is send back to User-B.

25) RTP media is established.

A.1.2 Communication Deflection

The flow below describes the Immediate CD feature the only difference compared to a regular CD is that in the regular CD case the "302 (Moved Temporarily) Moved Temporarily" is preceded by a "180 (Ringing) Ringing".

Figure A.2a

Figure A.2b

User B has activated the CD service.

User A is sending a communication request towards User B:

1 to 2) Initial INVITE request towards user B. The URI-B is subscribed to the CFU service.

2a to 3) The based on the IFC the INVITE is forwarded to the AS.

4 to 7) The INVITE is forwarded to user B due to normal communication procedures.

8 to 10) A 302 with a contact header including the URI of the forwarded to user is sent back to the AS.

11) The CD logic is executed.

12 to 14) A 181 may be send towards the User A indicating that the communication is diverted.

15 to 18) A Invite including URI-C as destination is sent back to the S-CSCF. Additional the History Header is included.

History-Info: <sip:User-B@example.com?Reason=sip%3Bcause=302>;index=1,
<sip:User-C@example.com;cause=480>index=2.

19 to 24) A 180 is sent back to the originating user including a history header as shown above. If no restriction is given the diverted to user will be presented at the UE of user A.

25 to 30) The 200 OK is sent Back to the User-A.

31 to 36) The ACK is send back to User-B.

37) RTP media is established.

A.1.3 Communication Forwarding on non Reply

Figure A.3a

Figure A.3b

User B has activated the CFNR service.

User A is sending a communication request towards User B:

1 to 2) Initial INVITE request towards user B. The URI-B is subscribed to the CFU service.

3) The based on the IFC the INVITE is forwarded to the AS.

4) he INVITE is forwarded to user B due to normal communication procedures.

5) The non-reply timer in the AS is started.

6 to 7) The INVITE is forwarded to user B due to normal communication procedures.

8 to 14) A 180 is sent back to the originating user indicating that the terminating UE is ringing.

15) The timer expires.

16 to 18) A 181 may be send towards the User A indicating that the communication is diverted.

19 to 21) To release the communication to User B the AS sends a CANCEL.

22 to 27) A 487 response with a ACK finalize the termination of the dialog between AS and UE:B.

28 to 31) A INVITE including URI-C as destination is sent back towards the UE:C. Additional the History Header is included.
History-Info: <sip:User-B@example.com>;index=1,
<sip:User-C@example.com;\target=sip:User-B%40example.com;cause=408> index=1.1.

32 to 34) The 200 OK for the CANCKE is sent Back to the User-A.

35 to 40) A 180 is sent back to the originating user including a history header as shown above. If no restriction is given the diverted to user will be presented at the UE of user A.

41 to 46) The 200 OK is sent Back to the User-A.

47 to 52 ) The ACK is send back to User-B.

53) RTP media is established.

A.1.4 Communication Forwarding on Busy

Figure A.4a

Figure A.4b

A.1.5 Communication Forwarding Not Logged-in (CFNL)

Figure A.5