A.4 Signalling flows for establishment of collaborative session for inter-UE transfer
24.3373GPPIP Multimedia (IM) Core Network (CN) subsystem IP Multimedia Subsystem (IMS) inter-UE transferRelease 17Stage 3TS
A.4.1 Introduction
This clause describes signalling flows for establishing a collaborative session. Two different scenarios have been considered:
– subclause A.4.3 shows an example where the collaborative session is established by transferring a media component from the controller UE to a controllee UE; and
– subclause A.4.3 and shows an example where the collaborative session is established by adding a new media component on a controllee UE.
A.4.2 Collaborative session establishment with media transfer
Figure A.4.2: Controller UE establishes a cllaborative session by transferring a media from controller UE to controllee UE
NOTE 1: For clarity, the SIP 100 (Trying) responses are not shown in the signalling flow.
1-2. SIP REFER request (SIP REFER request from UE-1 to SCC-AS)
There is an existing session with audio and video between controller UE, UE-1 (123.45.67.89), and remote UE (132.54.76.98). The video component is bidirectional from the remote UE to the controller UE, UE-1. The Controller UE attempts to transfer the video portion of this session to the controllee UE, UE-2.
Table A.4.2-1 SIP REFER request (UE-1 to SCC-AS)
REFER sip:interUEtransfer@sccas1.home1.net SIP/2.0
Via:
To: sip:interUEtransfer@sccas1.home1.net
From: sip:user1_public1@home1.net; tag=13579
Call-ID: cb03a0s09a2sdfglkj490333
CSeq: 93809824 REFER
Max-Forwards: 70
P-Preferred-Identity:
Refer-To: <sip:user1_public2@home1.net;gr=urn:uuid:f81d4fae-7dec-11d0-a765-00a0c91e6bf6?body= m%3Daudio%200%20RTP%2FAVP%97%0Dm%3Dvideo%203002%20RTP%2FAVP%2098%2099>
Require: target-dialog
Target-dialog: cb03a0s09a2sdfglkj321576;remote-tag=abcdef;local-tag=123456
Contact: <sip:user1_public1@home1.net;gr=urn:uuid:f81d4fae-7dec-11d0-a765-00a0c91ewxyz>;+g.3gpp.iut-controller
Referred-By: sip:user1_public1@home1.net
Accept: application/sdp, message/sipfrag
Content-Length: 0
3-4. SIP 200 (OK) response (from SCC AS to UE-1)
The SCC-AS sends a SIP 200 (OK) response to controller UE-1 as response to the SIP REFER request.
5-6. SIP NOTIFY request (from SCC AS to UE-1)
The SCC-AS sends a SIP NOTIFY request to controller UE-1 to notify implicit subscription to the SIP REFER request results.
Table A.4.2-5 SIP NOTIFY request (SCC-AS to UE-1)
NOTIFY sip:user1_public1@home1.net;gr=urn:uuid:f81d4fae-7dec-11d0-a765-00a0c91ewxyz SIP/2.0
Via:
To: sip:user1_public1@home1.net;tag=24680
From: sip:interUEtransfer@sccas1.home1.net;tag=13579
Call-ID: cb03a0s09a2sdfglkj490333
CSeq:
Max-Forwards:
P-Asserted-Identity:
Require:
Contact: sip: scc-as@home1.net
Allow:
Event: refer
Subscription-State: active;expires=3600
Content-Type: message/sipfrag ;version=2.0
Content-Length: (…)
SIP/2.0 100 Trying
7-8. SIP 200 (OK) response (from UE-1 AS to SCC-AS)
The controller UE, UE-1, acknowledges the SIP NOTIFY request by sending a SIP 200 (OK) response to the SCC-AS.
9-10. SIP INVITE request (from SCC-AS to UE-2)
The SCC-AS sends a SIP INVITE request to the controllee UE, UE-2, to transfer video media.
Table A.4.2-9 SIP INVITE request (SCC-AS to UE-2)
INVITE sip:user1_public2@home1.net;gr=urn:uuid:f81d4fae-7dec-11d0-a765-00a0c91e6bf6 SIP/2.0
Via:
To: sip:user1_public2@home1.net;
From: sip:interUEtransfer@sccas1.home1.net; tag=27365
Call-ID: cb03a0s09a2sdfglkj22222
CSeq:
Max-Forwards:
P-Asserted-Identity:
Require:
Referred-By: sip:user1_public1@home1.net
Contact:
Allow:
Content-Type: application/sdp
Content-Length: (…)
v=0
o=- 1027933615 1027933615 IN 132.54.76.98
s=-
c=IN IP4 132.54.76.98
t=0 0
m=audio 0 RTP/AVP 97
m=video 3002 RTP/AVP 98 99
b=AS:75
a=rtpmap:98 H263
a=fmtp:98 profile-level-id=0
a=rtpmap:99 MP4V-ES
a=sendonly
11-12. SIP 200 (OK) response (from UE-2 to SCC-AS)
The controllee UE, UE-2, acknowledges the SIP INVITE request by sending a SIP 200 (OK) response to the SCC-AS.
Table A.4.2-11 SIP 200 (OK) response (UE-2 to SCC-AS)
SIP/2.0 200 OK
Via:
To: sip:user1_public2@home1.net; tag = 27365
From: sip:interUEtransfer@sccas1.home1.net; tag = 36527
Call-ID: cb03a0s09a2sdfglkj22222
CSeq:
P-Preferred-Identity:
Contact: sip:user1_public2@home1.net;gr=urn:uuid:f81d4fae-7dec-11d0-a765-00a0c91e6bf6
Allow:
Content-Type: application/sdp
Content-Length: (…)
v=0
o=- 1027933615 1027933615 IN IP4 145.23.77.88
s=-
c=145.23.77.88
t=0 0
m=audio 0 RTP/AVP 97
m=video 1302 RTP/AVP 98 99
b=AS:75
a=rtpmap:98 H263
a=fmtp:98 profile-level-id=0
a=rtpmap:99 MP4V-ES
a=inactive
13-14. SIP ACK request (from SCC-AS to UE-2)
The SCC-AS sends a SIP ACK request to the controllee UE, UE-2.
15-16. SIP re-INVITE request (from SCC-AS to UE-1)
The SCC-AS sends a SIP re-INVITE request to the controller UE, UE-1.
Table A.4.2-15 SIP INVITE request (SCC-AS to UE-1)
INVITE sip:user1_public1@home1.net;gr=urn:uuid:f81d4fae-7dec-11d0-a765-00a0c91ewxyz SIP/2.0
Via:
To: sip:user1_public1@home1.net;tag=11928
From: sip:user3_public3@home3.net;tag = 27364
Call-ID: cb03a0s09a2sdfglkj11111
CSeq:
Max-Forwards:
P-Asserted-Identity:
Require:
Contact:
Allow:
Content-Type: application/sdp
Content-Length: (…)
v=0
o=- 1027933615 1027933615 IN IP4 132.54.76.98
s=-
c=IN IP4 132.54.76.98
t=0 0
m=audio 3000 RTP/AVP 96 97
b=AS:25.4
a=rtpmap:96 AMR
a=fmtp:96 mode-set=0,2,5,7; mode-change-period=2
a=rtpmap:97 telephone-event
a=maxptime:20
m=video 3002 RTP/AVP 98 99
a=sendonly
a=rtpmap:98 H263
a=fmtp:98 profile-level-id=0
a=rtpmap:99 MP4V-ES
17-18. SIP 200 (OK) response (from UE-1 to SCC-AS)
The controller UE, UE-1, acknowledges the SIP re-INVITE request by sending a SIP 200 (OK) response to the SCC-AS.
Table A.4.2-17 SIP 200 (OK) response (UE-1 to SCC-AS)
SIP/2.0 200 OK
Via:
To: sip:user3_public3@home3.net;tag = 27364
From: sip:user1_public1@home1.net;tag=11928
Call-ID: cb03a0s09a2sdfglkj11111
CSeq:
P-Preferred-Identity:
Contact: sip:user1_public2@home1.net;gr=urn:uuid:f81d4fae-7dec-11d0-a765-00a0c91e6bf6
Allow:
Content-Type: application/sdp
Content-Length: (…)
v=0
o=- 1027933615 1027933615 IN IP4 145.23.77.88
s=-
c=145.23.77.88
t=0 0
m=audio 1300 RTP/AVP 97
b=AS:25.4
a=rtpmap:96 AMR
a=fmtp:96 mode-set=0,2,5,7; mode-change-period=2
a=rtpmap:97 telephone-event
a=maxptime:20
m=video 1302 RTP/AVP 98 99
b=AS:75
a=rtpmap:98 H263
a=fmtp:98 profile-level-id=0
a=rtpmap:99 MP4V-ES
a=inactive
19-20. SIP ACK request (from SCC-AS to UE-1)
The SCC-AS sends a SIP ACK request to the controlle1 UE, UE-1, in response to the SIP 200 (OK) response.
21-22. SIP re-INVITE request (from SCC-AS to remote UE)
The SCC-AS sends a SIP re-INVITE request to the remote UE.
Table A.4.2-21 SIP INVITE request (SCC-AS to remote UE)
INVITE sip:user3_public3@home3.net SIP/2.0
Via:
To: sip:user3_public3@home3.net;tag = 11928
From: sip:user1_public1@home1.net; tag=27364
Call-ID: cb03a0s09a2sdfglkj11111
CSeq:
Max-Forwards:
P-Asserted-Identity:
Require:
Contact: sip:user1_public1@home1.net;gr=urn:uuid:f81d4fae-7dec-11d0-a765-00a0c91ewxyz
Allow:
Content-Type: application/sdp
Content-Length: (…)
v=0
o=- 1027933615 1027933615 IN IP4 123.45.67.89
s=-
t=0 0
m=audio 1300 RTP/AVP 96 97
c=IN IP4 123.45.67.89
b=AS:25.4
a=rtpmap:96 AMR
a=fmtp:96 mode-set=0,2,5,7; mode-change-period=2
a=rtpmap:97 telephone-event
a=maxptime:20
m=video 1302 RTP/AVP 98 99
c=IN IP4 145.23.77.88
b=AS:75
a=rtpmap:98 H263
a=fmtp:98 profile-level-id=0
a=rtpmap:99 MP4V-ES
23-24. SIP 200 (OK) response (from remote UE to SCC-AS)
The remote UE acknowledges the SIP re-INVITE request by sending a SIP 200 (OK) response to the SCC-AS.
Table A.4.2-23 SIP 200 (OK) response (remote UE to SCC-AS)
SIP/2.0 200 OK
Via:
To: sip:user1_public1@home1.net; tag=27364
From: sip:user3_public3@home3.net;tag = 11928
Call-ID: cb03a0s09a2sdfglkj11111
CSeq:
P-Asserted-Identity:
Contact: sip:user3_public3@home3.net
Allow:
Content-Type: application/sdp
Content-Length: (…)
v=0
o=- 1027933615 1027933615 IN IP4 132.54.76.98
s=-
c=IN IP4 132.54.76.98
t=0 0
m=audio 3000 RTP/AVP 96 97
b=AS:25.4
a=rtpmap:96 AMR
a=fmtp:96 mode-set=0,2,5,7; mode-change-period=2
a=rtpmap:97 telephone-event
a=maxptime:20
m=video 3002 RTP/AVP 98 99
b=AS:75
a=rtpmap:98 H263
a=fmtp:98 profile-level-id=0
a=rtpmap:99 MP4V-ES
25-26. SIP ACK request (from SCC-AS to remote UE)
The SCC-AS sends a SIP ACK request to the remote UE.
27-28. SIP re-INVITE request (from SCC-AS to UE-1)
The SCC-AS sends a SIP re-INVITE request to the controller UE, UE-1.
Table A.4.2-27 SIP INVITE request (SCC-AS to UE-1)
INVITE sip:user1_public1@home1.net;gr=urn:uuid:f81d4fae-7dec-11d0-a765-00a0c91ewxyz SIP/2.0
Via:
To: sip:user1_public1@home1.net;tag=11928
From: sip:user3_public3@home3.net;tag = 27364
Call-ID: cb03a0s09a2sdfglkj11111
CSeq:
Max-Forwards:
P-Asserted-Identity:
Require:
Contact:
Allow:
Content-Type: application/sdp
Content-Length: (…)
v=0
o=- 1027933615 1027933615 IN IP4 132.54.76.98
s=-
c=IN IP4 132.54.76.98
t=0 0
m=audio 3000 RTP/AVP 96 97
b=AS:25.4
a=rtpmap:96 AMR
a=fmtp:96 mode-set=0,2,5,7; mode-change-period=2
a=rtpmap:97 telephone-event
a=maxptime:20
m=video 0 RTP/AVP 98 99
29-30. SIP 200 (OK) response (from UE-1 to SCC-AS)
The controller UE, UE-1, acknowledges the SIP re-INVITE request by sending a SIP 200 (OK) response to the SCC-AS.
Table A.4.2-29 SIP 200 (OK) response (UE-1 to SCC-AS)
SIP/2.0 200 OK
Via:
To: sip:user3_public3@home3.net;tag = 27364
From: sip:user1_public1@home1.net;tag=11928
Call-ID: cb03a0s09a2sdfglkj11111
CSeq:
P-Preferred-Identity:
Contact: sip:user1_public2@home1.net;gr=urn:uuid:f81d4fae-7dec-11d0-a765-00a0c91e6bf6
Allow:
Content-Type: application/sdp
Content-Length: (…)
v=0
o=- 1027933615 1027933615 IN IP4 145.23.77.88
s=-
c=145.23.77.88
t=0 0
m=audio 1300 RTP/AVP 97
b=AS:25.4
a=rtpmap:96 AMR
a=fmtp:96 mode-set=0,2,5,7; mode-change-period=2
a=rtpmap:97 telephone-event
a=maxptime:20
m=video 0 RTP/AVP 98 99
31-32. SIP ACK request (from SCC-AS to UE-1)
The SCC-AS sends a SIP ACK request to the controlle1 UE, UE-1, in response to the SIP 200 (OK) response.
33-34. SIP re-INVITE request (from SCC-AS to UE-2)
The SCC-AS sends a SIP re-INVITE request to UE-2 to activate the video media components.
Table A.4.2-33 SIP INVITE request (SCC-AS to UE-2)
INVITE sip:user1_public2@home1.net;gr=urn:uuid:f81d4fae-7dec-11d0-a765-00a0c91e6bf6 SIP/2.0
Via:
To: sip:user1_public2@home1.net;
From: sip:interUEtransfer@sccas1.home1.net; tag=27365
Call-ID: cb03a0s09a2sdfglkj22222
CSeq:
Max-Forwards:
P-Asserted-Identity:
Require:
Referred-By: sip:user1_public1@home1.net
Contact:
Allow:
Content-Type: application/sdp
Content-Length: (…)
v=0
o=- 1027933615 1027933615 IN IP4 132.54.76.98
s=-
c=IN IP4 132.54.76.98
t=0 0
m=audio 0 RTP/AVP 97
m=video 3002 RTP/AVP 98 99
b=AS:75
a=rtpmap:98 H263
a=fmtp:98 profile-level-id=0
a=rtpmap:99 MP4V-ES
a=sendrecv
35-36. SIP 200 (OK) response (from UE-2 to SCC-AS)
The controllee UE, UE-2, acknowledges the SIP INVITE request by sending a SIP 200 (OK) response to the SCC-AS.
Table A.4.2-35 SIP 200 (OK) response (UE-2 to SCC-AS)
SIP/2.0 200 OK
Via:
To: sip:user1_public2@home1.net; tag = 27365
From: sip:interUEtransfer@sccas1.home1.net; tag = 36527
Call-ID: cb03a0s09a2sdfglkj22222
CSeq:
P-Preferred-Identity:
Contact: sip:user1_public2@home1.net;gr=urn:uuid:f81d4fae-7dec-11d0-a765-00a0c91e6bf6
Allow:
Content-Type: application/sdp
Content-Length: (…)
v=0
o=- 1027933615 1027933615 IN IP4 145.23.77.88
s=-
c=145.23.77.88
t=0 0
m=audio 0 RTP/AVP 97
m=video 1302 RTP/AVP 98 99
b=AS:75
a=rtpmap:98 H263
a=fmtp:98 profile-level-id=0
a=rtpmap:99 MP4V-ES
a=sendrecv
37-38. SIP ACK request (from SCC-AS to UE-2)
The SCC-AS sends a SIP ACK request to the controllee UE, UE2.
39-40. SIP NOTIFY request (from SCC-AS to UE-1)
The SCC-AS sends a SIP NOTIFY request to controller UE, UE-1, to inform about the success status of the inter-UE transfer.
Table A.4.2-39 SIP NOTIFY request (SCC-AS to UE-1)
NOTIFY sip:user1_public1@home1.net;gr=urn:uuid:f81d4fae-7dec-11d0-a765-00a0c91ewxyz SIP/2.0
Via:
To: sip:user1_public1@home1.net; tag=24680
From: sip:interUEtransfer@sccas1.home1.net;tag=13579
Call-ID:
CSeq:
Max-Forwards:
P-Asserted-Identity:
Require:
Contact: sip: scc-as@home1.net
Allow:
Event: refer
Subscription-State:terminated; reason=noresource
Content-Type: message/sipfrag ;version=2.0
Content-Length: (…)
SIP/2.0 200 OK
Content-Type: application/sdp
v=0
o=- 1027933615 1027933615 IN IP4 145.23.77.88
s=-
c=145.23.77.88
t=0 0
m=audio 0 RTP/AVP 97
m=video 1302 RTP/AVP 98 99
b=AS:75
a=rtpmap:98 H263
a=fmtp:98 profile-level-id=0
a=rtpmap:99 MP4V-ES
a=sendrecv
41-42. SIP 200 (OK) response (from UE-1 to SCC-AS)
The controller UE, UE-1, acknowledges the SIP NOTIFY request by sending a SIP 200 (OK) response to the SCC-AS.
A.4.3 Collaborative session establishment with new media
There is an existing session with audio between controller UE, UE-1, and the remote UE. The controller UE establishes a collaborative session by adding a video media component to the controllee UE, UE-2.
Figure A.4.3: Controller UE establishes a collaborative session by adding a new media on controllee UE
NOTE: For clarity, the SIP 100 (Trying) responses are not shown in the signalling flow.
1-2. SIP REFER request (from UE-1 to SCC-AS)
The controller UE, UE-1 sends a SIP REFER request to the SCC AS containing a Refer-To header field containing the GRUU of controllee UE, UE-2 and a body parameter containing an m line for audio set to zero and an m line for video with the port number set to the discard port number "9" since the port number is unknown. The SIP REFER request also includes a Target-dialog header field containing the details of the dialog for the existing session between controller UE, UE-1 and the remote UE.
Table A.4.3-1 SIP REFER request (UE-1 to SCC-AS)
REFER sip:interUEtransfer@sccas1.home1.net SIP/2.0
Via:
To: sip:interUEtransfer@sccas1.home1.net
From: sip:user1_public1@home1.net;tag=24680
Call-ID: cb03a0s09a2sdfglkj490333
CSeq: 93809824 REFER
Max-Forwards: 70
P-Preferred-Identity: sip:user1_public1@home1.net
Refer-To: <sip:user1_public2@home2.net;gr=urn:uuid:f81d4fae-7dec-11d0-a762-00a0c91e6bf6?body=m%3Daudio%200%20RTP%2FAVP%2096%0Dm%3Dvideo%209%20RTP%2FAVP%2098%2099>
Require: target-dialog
Target-dialog: cb03a0s09a2sdfglkj13579; remote-tag=abcdef; local-tag=123456
Referred-By: sip:user1_public1@home1.net
Contact: <sip:user1_public1@home1.net; gr=urn:uuid:f81d4fae-7dec-11d0-a765-00a0c91ewxyz>;+g.3gpp.iut-controller
Allow:
Accept: message/sipfrag
Content-Length: 0
3-4. SIP 200 (OK) response (from SCC AS to UE-1)
The SCC-AS sends a SIP 200 (OK) response to controller UE-1 as response to the SIP REFER request.
5-6. SIP NOTIFY request (from SCC AS to UE-1)
The SCC-AS sends a SIP NOTIFY request to UE-1 notifying implicit subscription to the SIP REFER request.
Table A.4.3-5 SIP NOTIFY request (SCC-AS to UE-1)
NOTIFY
Via:
To: sip:user1_public1@home1.net;tag=24680
From: sip:interUEtransfer@sccas1.home1.net;tag=13579
Call-ID:
CSeq:
Max-Forwards:
P-Asserted-Identity:
Require:
Contact: sip: scc-as@home1.net
Allow:
Event: refer
Subscription-State: active;expires=3600
Content-Type: message/sipfrag;version=2.0
Content-Length: (…)
SIP/2.0 100 Trying
7-8. SIP 200 (OK) response (from UE-1 to SCC-AS)
The controller UE, UE-1, acknowledges the SIP NOTIFY request by sending a SIP 200 (OK) response to the SCC-AS.
9-10. SIP INVITE request (from SCC-AS to UE-2)
The SCC-AS sends a SIP INVITE request to the controllee UE, UE-2, adding video media and establishing a collaborative session. Since the URI parameters indicate that the port number for the video m-line is set to the discard port number "9", the SCC AS realizes that the port number of the remote UE is unknown and therefore adds an a-line to inactive in the SDP offer to prevent the controllee UE sending media to the remote UE. The SDP offer contains the audio media component on controller UE, UE-1 set to zero.
Table A.4.3-9 SIP INVITE request (SCC-AS to UE-2)
INVITE sip:user2_public1@home1.net;gr=urn:uuid:f81d4fae-7dec-11d0-a765-00a0c91e6bf6 SIP/2.0
Via:
Record-Route: sip:scc-as@home1.net
To: sip:user2_public1@home1.net;
From: sip:user3_public3@home3.net;tag=acegi
Call-ID:
CSeq:
Max-Forwards:
P-Asserted-Identity: "remote user" sip:user3_public3@home3.net
Require:
Contact: sip:user3_public3@home3.net;gr=urn:uuid:f81d4fae-17oct-11a1-a678-0054c91eabcd
Allow:
Content-Type: application/sdp
Content-Length:(…)
v=0
o=- 1027933615 1027933615 IN IP4 123.112.67.87
s=-
t=0 0
m=audio 0 RTP/AVP 0
m=video 9 RTP/AVP 98 99
a=inactive
c=0.0.0.0
b=AS:75
a=rtpmap:98 H263
a=fmtp:98 profile-level-id=0
a=rtpmap:99 MP4V-ES
The value of c-line is set to a domain name within the ".invalid" DNS top-level domain in case of IPv6 as described in IETF RFC 6157 [43].
11-12. SIP 200 (OK) response (from UE-2 to SCC-AS)
The controllee UE, UE-2, acknowledges the SIP INVITE request by sena ding SIP 200 (OK) response to the SCC-AS. In the following example, the controllee UE which has controller capabilities sends g.3gpp.iut-controller media feature tag in the Contact header field to indicate the support for the controller UE procedures.
Table A.4.3-11 SIP 200 (OK) response (UE-2 to SCC-AS)
SIP/2.0 200 OK
Via:
To: sip:user2_public1@home1.net;tag=xyzwv
From: sip:user3_public3@home3.net;tag=acegi
Call-ID:
CSeq:
P-Preferred-Identity:
Contact: sip:user1_public2@home2.net;gr=urn:uuid:f81d4fae-7dec-11d0-a765-00a0c91e6bf6;+g.3gpp.iut-controller
Allow: INVITE, PRACK, UPDATE
Content-Type: application/sdp
Content-Length: (…)
v=0
o=- 1027933615 1027933615 IN IP4 145.23.77.88
s=-
t=0 0
m=audio 0 RTP/AVP 0
m=video 9 RTP/AVP 98
a=inactive
c=145.23.77.88
b=AS:75
a=rtpmap:98 H263
a=fmtp:98 profile-level-id=0
13-14. SIP ACK request (from SCC-AS to controllee UE)
The SCC-AS sends a SIP ACK request to the remote UE.
15-16. SIP re-INVITE request (from SCC-AS to remote UE)
The SCC-AS sends a SIP re-INVITE request to the remote UE.
Table A.4.3-15 SIP re-INVITE request (SCC-AS to remote UE)
INVITE sip:user3_public3@home3.net;gr=urn:uuid:f81d4fae-17oct-11a1-a678-0054c91eabcd SIP/2.0
Via:
To: sip:user3_public3@home3.net;tag=66666
From: sip:user1_public1@home1.net;tag=33333
Call-ID:
CSeq:
Max-Forwards:
P-Asserted-Identity:
Require:
Contact: sip: user1_public1@home1.net;gr=urn:uuid:f81d4fae-7dec-11d0-a765-00a0c91ewxyz
Allow:
Content-Type: application/sdp
Content-Length: (…)
v=0
o=- 1027933615 1027933615 IN IP4 123.45.67.89
s=-
t=0 0
m=audio 1300 RTP/AVP 96 97
c=IN IP4 123.45.67.89
b=AS:25.4
a=rtpmap:96 AMR
a=fmtp:96 mode-set=0,2,5,7; mode-change-period=2
a=rtpmap:97 telephone-event
a=maxptime:20
m=video 1302 RTP/AVP 98
c=IN IP4 145.23.77.88
b=AS:75
a=rtpmap:98 H263
a=fmtp:98 profile-level-id=0
17-18. SIP 200 (OK) response (from remote UE to SCC-AS)
The remote UE acknowledges the SIP re-INVITE request by sending a SIP 200 (OK) response to the SCC-AS.
Table A.4.3-17 SIP 200 (OK) response (remote UE to SCC-AS)
SIP/2.0 200 OK
Via:
To:
From:
Call-ID:
CSeq:
P-Asserted-Identity:
Contact: sip:user3_public3@home3.net;gr=urn:uuid:f81d4fae-17oct-11a1-a678-0054c91eabcd
Allow:
Content-Type: application/sdp
Content-Length: (…)
v=0
o=- 1027933615 1027933615 IN IP4 123.112.67.87
s=-
c=IN IP4 123.112.67.87
t=0 0
m=audio 3000 RTP/AVP 96 97
b=AS:25.4
a=rtpmap:96 AMR
a=fmtp:96 mode-set=0,2,5,7; mode-change-period=2
a=rtpmap:97 telephone-event
a=maxptime:20
m=video 3002 RTP/AVP 98
b=AS:75
a=rtpmap:98 H263
a=fmtp:98 profile-level-id=0
19-20. SIP ACK request (from SCC-AS to remote UE)
The SCC-AS sends a SIP ACK request to the remote UE.
21-22. SIP re-INVITE request (from SCC-AS to UE-2)
The SCC-AS sends a SIP re-INVITE request to the controllee UE, UE-2 to inform the controllee UE about the port number for the video media component of the remote UE. The SCC AS adds an a-line set to active in the SDP offer. The SIP INVITE request contains a Referred-By header field containing the identity of UE-1 from the Referred-By header field from the SIP REFER request.
NOTE 1: This SIP re-INVITE request is triggered by the SIP REFER request in steps 1-2. The previous SIP INVITE request was generated by the SCC AS due to third party call control to allow sending this SIP re-INVITE request.
NOTE 2: Any other changes such as the IP address of the remote UE in case the remote UE uses different IP addresses for different media would also be updated in the SIP re-INVITE request.
Table A.4.3-21 SIP re-INVITE request (SCC-AS to UE-2)
INVITE sip:user1_public2@home2.net;gr=urn:uuid:f81d4fae-7dec-11d0-a765-00a0c91e6bf6 SIP/2.0
Via:
To:
From:
Call-ID:
CSeq:
Contact: sip:user3_public3@home3.net;gr=urn:uuid:f81d4fae-17oct-11a1-a678-0054c91eabcd
Referred-By: sip:user1_public1@home1.net
Allow:
Content-Type: application/sdp
Content-Length: (…)
v=0
o=- 1027933615 1027933615 IN IP4 123.45.67.87
s=-
c=IN IP4 123.45.67.87
t=0 0
m=audio 0 RTP/AVP 96 97
m=video 3002 RTP/AVP 98
b=AS:75
a=active
a=rtpmap:98 H263
a=fmtp:98 profile-level-id=0
23-24. SIP 200 (OK) response (from controllee UE to SCC-AS)
Table A.4.3-23 SIP 200 (OK) response (UE-2 to SCC-AS)
SIP/2.0 200 OK
Via:
To:
From:
Call-ID:
CSeq:
Contact: sip:user1_public2@home2.net;gr=urn:uuid:f81d4fae-7dec-11d0-a765-00a0c91e6bf6
Allow:
Content-Type: application/sdp
Content-Length: (…)
v=0
o=- 1027933615 1027933615 IN IP4 145.23.77.88
s=-
t=0 0
m=audio 0 RTP/AVP 0
m=video 1302 RTP/AVP 98
c=145.23.77.88
b=AS:75
a=active
a=rtpmap:98 H263
a=fmtp:98 profile-level-id=0
25-26. SIP ACK request (from SCC-AS to controllee UE)
The SCC-AS sends a SIP ACK request to the controllee UE to acknowledge.
27-28. SIP NOTIFY request (from SCC-AS to conroller UE, UE-1)
When the media component is added to the controllee UE, UE-2, the SCC-AS sends a SIP NOTIFY request to the controller UE, UE-1 to inform about the success status of adding the media to the controllee UE, UE-2.
Table A.4.3-27 SIP NOTIFY request (SCC-AS to UE-1)
NOTIFY
Via:
To: sip:user1_public1@home1.net;tag = 13579
From: sip:scc-as@home1.net;tag=24680
Call-ID:
CSeq:
Max-Forwards:
P-Asserted-Identity:
Require:
Contact: sip: scc-as@home1.net
Allow:
Event: refer
Subscription-State:terminated; reason=noresource
Content-Type: message/sipfrag ;version=2.0
Content-Length: (…)
SIP/2.0 200 OK
Content-Type: application/sdp
m=audio 0 RTP/AVP 0
m=video 1302 RTP/AVP 98 99
c=145.23.77.88
b=AS:75
a=active
a=rtpmap:98 H263
a=fmtp:98 profile-level-id=0
29-30. SIP 200 (OK) response (from controller UE to SCC-AS)
The controller UE acknowledges the NOTIFY request by sending a SIP 200 (OK) response to the SCC-AS.