A.4 CAT early session model signalling flows

24.1823GPPIP Multimedia Subsystem (IMS) Customized Alerting Tones (CAT)Protocol specificationRelease 17TS

Tools: ARFCN - Frequency Conversion for 5G NR/LTE/UMTS/GSM

A.4.1 Introduction

The following flows show establishment of a session between UE#1 and UE#2, using the early session model described in clause 4.5.5.3.3 to provide CAT to UE#1. The following flows are included:

– clause A.4.2 shows CAT, using the early session model, when UE#1 and UE#2 have resources available;

– clause A.4.3 shows CAT, using the early session model, when UE#1 does not have resources available;

– clause A.4.4 shows CAT, using the early session model, when UE#2 does not have resources available;

A.4.2 CAT when UE#1 and UE#2 have resources available

Figure A.4.2-1: CAT, no resource reservation

1 INVITE request (UE#1 to S-CSCF) see example in table A.4.2-1

UE#1 sends a SIP INVITE request to the intermediate IM CN subsystem.

Table A.4.2-1: INVITE request (UE#1 to S-CSCF)

INVITE tel:+1-212-555-2222 SIP/2.0

Via: SIP/2.0/UDP [5555::aaa:bbb:ccc:ddd]:1357;comp=sigcomp;branch=z9hG4bKnashds7

Max-Forwards: 70

Route: <sip:pcscf1.visited1.net:7531;lr;comp=sigcomp>, <sip:orig@scscf1.home1.net;lr>

P-Preferred-Identity: "John Doe" <sip:user1_public1@home1.net>

P-Access-Network-Info: 3GPP-UTRAN-TDD; utran-cell-id-3gpp=234151D0FCE11

Privacy: none

From: <sip:user1_public1@home1.net>;tag=171828

To: <tel:+1-212-555-2222>

Call-ID: cb03a0s09a2sdfglkj490333

Cseq: 127 INVITE

Recv-Info: infoDtmf

Supported: precondition, 100rel, early-session

Security-Verify: ipsec-3gpp; q=0.1; alg=hmac-sha-1-96; spi-c=98765432; spi-s=87654321; port-c=8642; port-s=7531

Contact: <sip:user1_public1@home1.net;gr=urn:uuid:f81d4fae-7dec-11d0-a765-00a0c91e6bf6>;+g.3gpp.icsi_ref="urn%3Aurn-7%3gpp-service.ims.icsi.mmtel"

Accept:application/sdp, application/3gpp-ims+xml

Content-Type: application/sdp

Content-Disposition: session

Content-Length: (…)

v=0

o=- 2987933615 2987933615 IN IP6 5555::aaa:bbb:ccc:ddd

s=-

c=IN IP6 5555::aaa:bbb:ccc:ddd

t=0 0

m=audio 3456 RTP/AVP 97 96

b=AS:25.4

a=curr:qos local sendrecv

a=curr:qos remote none

a=des:qos mandatory local sendrecv

a=des:qos none remote sendrecv

a=rtpmap:97 AMR

a=fmtp:97 mode-set=0,2,5,7; maxframes=2

a=rtpmap:96 telephone-event

Supported: The UE indicates support for preconditions, reliable provisional responses, and early-session SDP.

Recv-Info: The UE indicates willingness to receive DTMF Info Packages in INFO requests.

SDP: The SDP offer (SDP_O) contains a set of codecs supported by UE#1 and desired by the calling user for this session. If preconditions are used, the local preconditions are indicated as fulfilled.

2 INVITE request (S-CSCF to CAT-AS)

The S-CSCF forwards the SIP INVITE request to the CAT-AS.

The CAT-AS instructs the MRF to reserve CAT resources.

3-4 INVITE request (CAT-AS to UE#2)

The CAT-AS forwards the request to UE#2.

5-6 Reliable 180 (Ringing) provisional response (UE#2 to CAT-AS) see example in table A.4.2-5

The called party is alerted. UE#2 sends a SIP 180 (Ringing) provisional response for the INVITE request to the CAT-AS.

The CAT-AS terminates the provisional response.

Table A.4.2-5: 180 (Ringing) response (UE#2 to CAT-AS)

SIP/2.0 180 Ringing

Via: SIP/2.0/UDP pcscf2.visited2.net;branch=z9hG4bK472a32.1, SIP/2.0/UDP scscf2.home2.net;branch=z9hG4bK764z87.2, SIP/2.0/UDP catas.home2.net;branch=z9hG4bK871y12.1, SIP/2.0/UDP scscf2.home2.net;branch=z9hG4bK764z87.1, SIP/2.0/UDP scscf1.home1.net;branch=z9hG4bK332b23.1, SIP/2.0/UDP pcscf1.visited1.net;branch=z9hG4bK240f34.1, SIP/2.0/UDP [5555::aaa:bbb:ccc:ddd]:1357;comp=sigcomp;branch=z9hG4bKnashds7

From:

To: <tel:+1-212-555-2222>;tag=2236

Call-ID:

Cseq:

RSeq: 9022

Contact: <sip:user2_public1@home2.net;gr=urn:uuid:2ad8950e-48a5-4a74-8d99-ad76cc7fc74>;+g.3gpp.icsi_ref="urn%3Aurn-7%3gpp-service.ims.icsi.mmtel"

Content-Length: 0

7-8 183 (Session Progress) provisional response (CAT-AS to UE#1) see example in table A.4.2-7

The CAT-AS sends a reliable SIP 183 (Session Progress) provisional response to UE#1.

An early-session SDP is sent to the UE#1 via the 183 (Session Progress) provisional response.

Table A.4.2-7: 183 (Session Progress) response (CAT-AS to UE#1)

SIP/2.0 183 Session Progress

Via: SIP/2.0/UDP scscf2.home2.net;branch=z9hG4bK764z87.1, SIP/2.0/UDP scscf1.home1.net;branch=z9hG4bK332b23.1, SIP/2.0/UDP pcscf1.visited1.net;branch=z9hG4bK240f34.1, SIP/2.0/UDP [5555::aaa:bbb:ccc:ddd]:1357;comp=sigcomp;branch=z9hG4bKnashds7

From:

To:

Call-ID:

Cseq:

Require: precondition, 100rel, early-session

Recv-Info: dtmfInfo

RSeq: 9022

Contact:<sip:cat-as.home1.net>;+g.3gpp.icsi_ref="urn%3Aurn-7%3gpp-service.ims.icsi.mmtel"

Content-Type: application/sdp

Content-Disposition: early-session

Content-Length: (…)

v=0

o=- 2987933616 2987933616 IN IP6 5555::eee:fff:aaa:bbb

s=-

c=IN IP6 5555::ccc:aaa:bbb:acc

t=0 0

m=audio 3456 RTP/AVP 97

b=AS:25.4

a=curr:qos local sendrecv

a=curr:qos remote none

a=des:qos mandatory local sendrecv

a=des:qos mandatory remote sendrecv

a=rtpmap:97 AMR

a=fmtp:97 mode-set=0,2,5,7; maxframes

a=content:g.3gpp.cat

early SDP The early-session SDP offer (early SDP_O) contains a set of codecs supported to be used for CAT and, in this example, includes a SDP "a=content" attribute with a "g.3gpp.cat" value for each media description. The early-session SDP content is based on information received from the MRF. The local preconditions are indicated as fulfilled.

Recv-Info: The CAT-AS indicates willingness to receive DTMF Info Packages in INFO requests.

9-10 PRACK request (UE#1 to CAT-AS) see example in table A.4.2-9

UE#1 sends a SIP PRACK request with a early-session SDP answer, which acknowledges the SIP 183 (Session Progress) provisional response, towards UE#2.

The CAT-AS instructs the MRF to play CAT media.

Table A.4.2-9: PRACK request (UE#1 to CAT-AS)

PRACK sip:cat-as.home1.net SIP/2.0

Via: SIP/2.0/UDP [5555::aaa:bbb:ccc:ddd]:1357;comp=sigcomp;branch=z9hG4bKnashds7

Max-Forwards: 70

Route: <sip:pcscf1.visited1.net:7531;lr;comp=sigcomp>, <sip:orig@scscf1.home1.net;lr>

P-Preferred-Identity: "John Doe" <sip:user1_public1@home1.net>

P-Access-Network-Info: 3GPP-UTRAN-TDD; utran-cell-id-3gpp=234151D0FCE11

Privacy: none

From:

To:

Call-ID:

Cseq: 128 PRACK

Contact:

Content-Type: application/sdp

Content-Disposition: early-session

Content-Length: (…)

v=0

o=- 2987933616 2987933616 IN IP6 5555::aaa:bbb:ccc:ddd

s=-

c=IN IP6 5555::aaa:bbb:ccc:ddd

t=0 0

m=audio 3466 RTP/AVP 97

b=AS:25.4

a=curr:qos local sendrecv

a=curr:qos remote sendrecv

a=des:qos mandatory local sendrecv

a=des:qos none remote sendrecv

a=rtpmap:97 AMR

a=fmtp:97 mode-set=0,2,5,7; maxframes

early SDP The early-session SDP answer (early SDP_A) contains a set of codecs supported by UE#1 to be used for CAT. The local preconditions are indicated as fulfilled.

11-12 200 (OK) response to PRACK request (CAT-AS to UE#1)

The CAT-AS sends a SIP 200 (OK) response for the SIP PRACK request to UE#1.

13-14 200 (OK) response to INVITE request (UE#2 to CAT-AS) see example in table A.4.2-13

The called party answers the call. UE#2 sends a SIP 200 (OK) final response for the SIP INVITE request towards UE#1.

The CAT-AS instructs the MRF to stop CAT media.

Table A.4.2-13: 200 (OK) response (UE#2 to CAT-AS)

SIP/2.0 200 OK

Via: SIP/2.0/UDP pcscf2.visited2.net;branch=z9hG4bK361k21.1, SIP/2.0/UDP scscf2.home2.net;branch=z9hG4bK764XC12.1, SIP/2.0/UDP catas.home2.net;branch=z9hG4bK764Q32.1, SIP/2.0/UDP scscf2.home2.net;branch=z9hG4bK764z87.1, SIP/2.0/UDP scscf1.home1.net;branch=z9hG4bK332b23.1, SIP/2.0/UDP pcscf1.visited1.net;branch=z9hG4bK240f34.1, SIP/2.0/UDP [5555::aaa:bbb:ccc:ddd]:1357;comp=sigcomp;branch=z9hG4bKnashds7

From:

To:

Call-ID:

Cseq:

Contact: <sip:user2_public1@home2.net;gr=urn:uuid:2ad8950e-48a5-4a74-8d99-ad76cc7fc74 >;+g.3gpp.icsi_ref="urn%3Aurn-7%3gpp-service.ims.icsi.mmtel"

Content-Type: application/sdp

Content-Disposition: session

Content-Length: (…)

v=0

o=- 2987933615 2987933615 IN IP6 5555::eee:fff:aaa:bbb

s=-

c=IN IP6 6666::eee:fff:aaa:bbb

t=0 0

m=audio 3456 RTP/AVP 97 96

b=AS:25.4

a=curr:qos local sendrecv

a=curr:qos remote sendrecv

a=des:qos mandatory local sendrecv

a=des:qos mandatory remote sendrecv

a=rtpmap:97 AMR

a=fmtp:97 mode-set=0,2,5,7; maxframes=2

a=rtpmap:96 telephone-event

SDP The SDP answer (SDP_A) contains a set of codecs to be used for the session. If preconditions are used, they are indicated as fulfilled.

15-16 200 (OK) response to INVITE request (CAT-AS to UE#1)

The CAT-AS forwards the SIP 200 (OK) response to UE#1.

A regular session is established between UE#1 and UE#2.

The early session between UE#1 and the CAT-AS is terminated.

17 18 ACK request (UE#1 to UE#2)

UE#1 sends a SIP ACK request, which acknowledges the SIP 200 (OK) final response, to UE#2.

A.4.3 CAT when UE#1 does not have required resources available while UE#2 has resources available

Figure A.4.3-1: CAT, UE#1 does not have resources available

1-2 INVITE request (UE#1 to CAT-AS) see example in table A.4.3-1

UE#1 sends a SIP INVITE request to the intermediate IM CN subsystem.

Table A.4.3-1: INVITE request (UE#1 to S-CSCF)

INVITE tel:+1-212-555-2222 SIP/2.0

Via: SIP/2.0/UDP [5555::aaa:bbb:ccc:ddd]:1357;comp=sigcomp;branch=z9hG4bKnashds7

Max-Forwards: 70

Route: <sip:pcscf1.visited1.net:7531;lr;comp=sigcomp>, <sip:orig@scscf1.home1.net;lr>

P-Preferred-Identity: "John Doe" <sip:user1_public1@home1.net>

P-Access-Network-Info: 3GPP-UTRAN-TDD; utran-cell-id-3gpp=234151D0FCE11

Privacy: none

From: <sip:user1_public1@home1.net>;tag=171828

To: <tel:+1-212-555-2222>

Call-ID: cb03a0s09a2sdfglkj490333

Cseq: 127 INVITE

Recv-Info: infoDtmf

Supported: precondition, 100rel, early-session

Security-Verify: ipsec-3gpp; q=0.1; alg=hmac-sha-1-96; spi-c=98765432; spi-s=87654321; port-c=8642; port-s=7531

Contact: <sip:user1_public1@home1.net;gr=urn:uuid:f81d4fae-7dec-11d0-a765-00a0c91e6bf6>;+g.3gpp.icsi_ref="urn%3Aurn-7%3gpp-service.ims.icsi.mmtel"

Accept:application/sdp, application/3gpp-ims+xml

Content-Type: application/sdp

Content-Disposition: session

Content-Length: (…)

v=0

o=- 2987933615 2987933615 IN IP6 5555::aaa:bbb:ccc:ddd

s=-

c=IN IP6 5555::aaa:bbb:ccc:ddd

t=0 0

m=video 3400 RTP/AVP 98

b=AS:75

a=curr:qos local none

a=curr:qos remote none

a=des:qos mandatory local sendrecv

a=des:qos none remote sendrecv

a=rtpmap:98 H263

m=audio 3456 RTP/AVP 97 96

b=AS:25.4

a=curr:qos local none

a=curr:qos remote none

a=des:qos mandatory local sendrecv

a=des:qos none remote sendrecv

a=rtpmap:97 AMR

a=fmtp:97 mode-set=0,2,5,7; maxframes=2

a=rtpmap:96 telephone-event

Supported: The UE indicates support for preconditions, reliable provisional responses, and early-session SDP.

Recv-Info: The UE indicates willingness to receive DTMF Info Packages in INFO requests.

SDP The SDP offer (SDP_O1) contains a set of codecs supported by UE#1 and desired by the user at UE#1 for this session. The SDP contains an indication that the local preconditions are not fulfilled.

2 INVITE request (S-CSCF to CAT-AS)

The S-CSCF forwards the SIP INVITE request to the CAT-AS.

3-4 INVITE request (CAT-AS to UE#2)

The CAT-AS forwards the SIP INVITE request to UE#2.

5-6 183 (Session Progress) provisional response (UE#2 to CAT-AS) see example in table A.4.3-5

UE#2 sends a SIP 183 (Session Progress) provisional response for the INVITE request to the CAT-AS.

Table A.4.3-5: 183 (Session Progress) response (UE#2 to CAT-AS)

SIP/2.0 183 Session Progress

From:

To: <tel:+1-212-555-2222>;tag=6322

Call-ID:

Cseq:

Require: 100rel, precondition

RSeq: 9021

Contact: <sip:user2_public1@home2.net;gr=urn:uuid:2ad8950e-48a5-4a74-8d99-ad76cc7fc74>;+g.3gpp.icsi_ref="urn%3Aurn-7%3gpp-service.ims.icsi.mmtel"

Content-Type: application/sdp

Content-Disposition: session

Content-Length: (…)

v=0

o=- 2987933615 2987933615 IN IP6 5555::eee:fff:aaa:bbb

s=-

c=IN IP6 5555::eee:fff:aaa:bbb

t=0 0

m=video 3400 RTP/AVP 98

b=AS:75

a=curr:qos local sendrecv

a=curr:qos remote none

a=des:qos mandatory local sendrecv

a=des:qos mandatory remote sendrecv

a=rtpmap:98 H263

a=fmtp:98 profile-level-id=0

a=content:g.3gpp.cat

m=audio 3456 RTP/AVP 97 96

b=AS:25.4

a=curr:qos local sendrecv

a=curr:qos remote none

a=des:qos mandatory local sendrecv

a=des:qos mandatory remote sendrecv

a=rtpmap:97 AMR

a=fmtp:97 mode-set=0,2,5,7; maxframes=2

a=rtpmap:96 telephone-event

a=content:g.3gpp.cat

SDP The SDP answer (SDP_A1) contains a set of codecs to be used for the session and, in this example, includes a SDP "a=content" attribute with a "g.3gpp.cat" value for each media description. The local preconditions are indicated as fulfilled.

7-8 183 (Session Progress) provisional response (CAT-AS to UE#1) see example in table A.4.3-7

The CAT-AS forwards the SIP 183 (Session Progress) provisional response with early-session SDP for CAT to UE#1.

Table A.4.3-7: 183 (Session Progress) response (CAT-AS to UE#1)

SIP/2.0 183 Session Progress

From:

To:

Call-ID:

Cseq:

Require: 100rel, precondition, early-session

RSeq: 9021

Contact:

Content-Type: multipart/mixed; boundary="boundary1"

Content-Length: (…)

–boundary1

Content-Type: application/sdp

Content-Disposition: session

v=0

o=- 2987933615 2987933615 IN IP6 5555::eee:fff:aaa:bbb

s=-

c=IN IP6 6666::eee:fff:aaa:bbb

t=0 0

m=video 3400 RTP/AVP 98

b=AS:75

a=curr:qos local sendrecv

a=curr:qos remote none

a=des:qos mandatory local sendrecv

a=des:qos mandatory remote sendrecv

a=rtpmap:98 H263

a=fmtp:98 profile-level-id=0

m=audio 3456 RTP/AVP 97 96

b=AS:25.4

a=curr:qos local sendrecv

a=curr:qos remote none

a=des:qos mandatory local sendrecv

a=des:qos mandatory remote sendrecv

a=rtpmap:97 AMR

a=fmtp:97 mode-set=0,2,5,7; maxframes=2

a=rtpmap:96 telephone-event

–boundary1

Content-Type: application/sdp

Content-Disposition: early-session

v=0

o=- 2987933616 2987933616 IN IP6 5555::ccc:aaa:bbb:acc

s=-

c=IN IP6 5555::ccc:aaa:bbb:acc

t=0 0

m=video 3400 RTP/AVP 98

b=AS:75

a=curr:qos local none

a=curr:qos remote none

a=des:qos mandatory local sendrecv

a=des:qos mandatory remote sendrecv

a=rtpmap:98 H263

a=fmtp:98 profile-level-id=0

m=audio 3456 RTP/AVP 97

b=AS:25.4

a=curr:qos local none

a=curr:qos remote none

a=des:qos mandatory local sendrecv

a=des:qos mandatory remote sendrecv

a=rtpmap:97 AMR

a=fmtp:97 mode-set=0,2,5,7; maxframes

–boundary1

early SDP The early-session SDP offer (early SDP_O1) contains a set of codecs to be used for CAT. The preconditions are indicated as not fulfilled.

9-10 PRACK request (UE#1 to CAT-AS) see example in table A.4.3-9

UE#1 sends a SIP PRACK request with early-session SDP answer, which acknowledges the 183 (Session Progress) provisional response, towards UE#2.

Table A.4.3-9: PRACK request (UE#1 to CAT-AS)

PRACK sip:user2_public1@home2.net;gr=urn:uuid:2ad8950e-48a5-4a74-8d99-ad76cc7fc74 SIP/2.0

Via: SIP/2.0/UDP [5555::aaa:bbb:ccc:ddd]:1357;comp=sigcomp;branch=z9hG4bKna234s7

Max-Forwards: 70

Route: <sip:pcscf1.visited1.net:7531;lr;comp=sigcomp>, <sip:orig@scscf1.home1.net;lr>

P-Preferred-Identity: "John Doe" <sip:user1_public1@home1.net>

P-Access-Network-Info: 3GPP-UTRAN-TDD; utran-cell-id-3gpp=234151D0FCE11

Privacy: none

From:

To:

Call-ID:

Cseq: 128 PRACK

Contact:

Content-Type: application/sdp

Content-Disposition: early-session

Content-Length: (…)

v=0

o=- 2987933616 2987933616 IN IP6 5555::aaa:bbb:ccc:ddd

s=-

c=IN IP6 5555::aaa:bbb:ccc:ddd

t=0 0

m=video 3500 RTP/AVP 98

b=AS:75

a=curr:qos local none

a=curr:qos remote none

a=des:qos mandatory local sendrecv

a=des:qos none remote sendrecv

a=rtpmap:98 H263

m=audio 3556 RTP/AVP 97

b=AS:25.4

a=curr:qos local none

a=curr:qos remote none

a=des:qos mandatory local sendrecv

a=des:qos none remote sendrecv

a=rtpmap:97 AMR

a=fmtp:97 mode-set=0,2,5,7; maxframes

early SDP The early-session SDP answer (early SDP_A1) contains a set of codecs supported by UE#1 to be used for CAT. The preconditions are indicated as not fulfilled.

11-12 PRACK request (CAT-AS to UE#2) see example in table A.4.3-11

CAT-AS forwards the SIP PRACK request without early-session SDP answer to UE#2.

Table A.4.3-11: PRACK request (CAT-AS to UE#2)

PRACK sip:user1_public1@home1.net;gr=urn:uuid:f81d4fae-7dec-11d0-a765-00a0c91e6bf6 SIP/2.0

Via: SIP/2.0/UDP catas.home2.net;branch=z9hG4bK614Q63.1, SIP/2.0/UDP scscf2.home2.net;branch=z9hG4bK464z73.1, SIP/2.0/UDP scscf1.home1.net;branch=z9hG4bK351b51.1, SIP/2.0/UDP pcscf1.visited1.net;branch=z9hG4bK582f12.1, SIP/2.0/UDP [5555::aaa:bbb:ccc:ddd]:1357;comp=sigcomp;branch=z9hG4bKna234s7

Max-Forwards: 66

Privacy:

From:

To:

Call-ID:

Cseq: 128 PRACK

Contact:

Content-Length: 0

13-16 200 (OK) response to PRACK request (UE#2 to UE#1)

UE#2 sends a SIP 200 (OK) response for the SIP PRACK request to UE#1.

17-18 UPDATE request (UE#1 to CAT-AS) see example in table A.4.3-17

UE#1 reserved resources for regular session and early session, it sends an SIP UPDATE request with session SDP offer and early-session SDP offer towards UE#2.

Table A.4.3-17: UPDATE request (UE#1 to CAT-AS)

UPDATE sip:user2_public1@home2.net;gr=urn:uuid:2ad8950e-48a5-4a74-8d99-ad76cc7fc74 SIP/2.0

Via: SIP/2.0/UDP [5555::aaa:bbb:ccc:ddd]:1357;comp=sigcomp;branch=z9hG4bKna234s7

Max-Forwards: 70

Route: <sip:pcscf1.visited1.net:7531;lr;comp=sigcomp>, <sip:orig@scscf1.home1.net;lr>

P-Preferred-Identity: "John Doe" <sip:user1_public1@home1.net>

P-Access-Network-Info: 3GPP-UTRAN-TDD; utran-cell-id-3gpp=234151D0FCE11

Privacy: none

From:

To:

Call-ID:

Cseq: 129 UPDATE

Contact:

Content-Type: multipart/mixed; boundary="boundary1"

Content-Length: (…)

–boundary1

Content-Type: application/sdp

Content-Disposition: session

v=0

o=- 2987933615 2987933615 IN IP6 5555::aaa:bbb:ccc:ddd

s=-

c=IN IP6 5555::aaa:bbb:ccc:ddd

t=0 0

m=video 3400 RTP/AVP 98

b=AS:75

a=curr:qos local sendrecv

a=curr:qos remote sendrecv

a=des:qos mandatory local sendrecv

a=des:qos mandatory remote sendrecv

a=rtpmap:98 H263

a=fmtp:98 profile-level-id=0

m=audio 3456 RTP/AVP 97 96

b=AS:25.4

a=curr:qos local sendrecv

a=curr:qos remote sendrecv

a=des:qos mandatory local sendrecv

a=des:qos mandatory remote sendrecv

a=rtpmap:97 AMR

a=fmtp:97 mode-set=0,2,5,7; maxframes=2

a=rtpmap:96 telephone-event

–boundary1

Content-Type: application/sdp

Content-Disposition: early-session

v=0

o=- 2987933616 2987933616 IN IP6 5555::aaa:bbb:ccc:ddd

s=-

c=IN IP6 5555::aaa:bbb:ccc:ddd

t=0 0

m=video 3500 RTP/AVP 98

b=AS:75

a=curr:qos local sendrecv

a=curr:qos remote none

a=des:qos mandatory local sendrecv

a=des:qos mandatory remote sendrecv

a=rtpmap:98 H263

a=fmtp:98 profile-level-id=0

m=audio 3556 RTP/AVP 97

b=AS:25.4

a=curr:qos local sendrecv

a=curr:qos remote none

a=des:qos mandatory local sendrecv

a=des:qos mandatory remote sendrecv

a=rtpmap:97 AMR

a=fmtp:97 mode-set=0,2,5,7; maxframes

–boundary1

SDP The offer (SDP_O2) contains a set of codecs supported by UE#1 and desired by the user at UE#1 for this session. The SDP contains an indication that the preconditions are fulfilled.

early SDP The early-session SDP offer (early SDP_O2) contains a set of codecs supported by UE#1 to be used for CAT. The local preconditions are indicated as fulfilled.

19-20 UPDATE request (CAT-AS to UE#2) see example in table A.4.3-19

CAT-AS forwards the SIP UPDATE request towards UE#2 without early-session SDP.

The CAT-AS instructs the MRF to reserve CAT resources.

Table A.4.3-19: UPDATE request (CAT-AS to UE#2)

UPDATE sip:user2_public1@home2.net;gr=urn:uuid:2ad8950e-48a5-4a74-8d99-ad76cc7fc74 SIP/2.0

Via: SIP/2.0/UDP catas.home2.net;branch=z9hG4bK164Q63.1, SIP/2.0/UDP scscf2.home2.net;branch=z9hG4bK442z73.1, SIP/2.0/UDP scscf1.home1.net;branch=z9hG4bK514b51.1, SIP/2.0/UDP pcscf1.visited1.net;branch=z9hG4bK812f12.1, SIP/2.0/UDP [5555::aaa:bbb:ccc:ddd]:1357;comp=sigcomp;branch=z9hG4bKna234s7

Max-Forwards: 66

Privacy:

From:

To:

Call-ID:

Cseq: 129 UPDATE

Contact:

Content-Type: application/sdp

Content-Disposition: session

Content-Length: (…)

v=0

o=- 2987933615 2987933615 IN IP6 5555::aaa:bbb:ccc:ddd

s=-

c=IN IP6 5555::aaa:bbb:ccc:ddd

t=0 0

m=video 3400 RTP/AVP 98

b=AS:75

a=curr:qos local sendrecv

a=curr:qos remote sendrecv

a=des:qos mandatory local sendrecv

a=des:qos mandatory remote sendrecv

a=rtpmap:98 H263

a=fmtp:98 profile-level-id=0

m=audio 3456 RTP/AVP 97 96

b=AS:25.4

a=curr:qos local sendrecv

a=curr:qos remote sendrecv

a=des:qos mandatory local sendrecv

a=des:qos mandatory remote sendrecv

a=rtpmap:97 AMR

a=fmtp:97 mode-set=0,2,5,7; maxframes=2

a=rtpmap:96 telephone-event

21-22 200 (OK) response to UPDATE request (UE#2 to CAT-AS) see example in table A.4.3-21

UE#2 sends a SIP 200 (OK) for the SIP UPDATE request to the CAT-AS.

Table A.4.3-21: 200 (OK) response (UE#2 to CAT-AS)

SIP/2.0 200 OK

Via: SIP/2.0/UDP pcscf2.visited2.net;branch=z9hG4bK611k21.1, SIP/2.0/UDP scscf2.home2.net;branch=z9hG4bK764KS12.1, SIP/2.0/UDP catas.home2.net;branch=z9hG4bK164Q63.1, SIP/2.0/UDP scscf2.home2.net;branch=z9hG4bK442z73.1, SIP/2.0/UDP scscf1.home1.net;branch=z9hG4bK514b51.1, SIP/2.0/UDP pcscf1.visited1.net;branch=z9hG4bK812f12.1, SIP/2.0/UDP [5555::aaa:bbb:ccc:ddd]:1357;comp=sigcomp;branch=z9hG4bKna234s7

From:

To:

Call-ID:

Cseq:

Contact:

Content-Type: application/sdp

Content-Disposition: session

Content-Length: (…)

v=0

o=- 2987933615 2987933615 IN IP6 5555::eee:fff:aaa:bbb

s=-

c=IN IP6 5555::eee:fff:aaa:bbb

t=0 0

m=video 3400 RTP/AVP 98

b=AS:75

a=curr:qos local sendrecv

a=curr:qos remote sendrecv

a=des:qos mandatory local sendrecv

a=des:qos mandatory remote sendrecv

a=rtpmap:98 H263

a=fmtp:98 profile-level-id=0

m=audio 3456 RTP/AVP 97 96

b=AS:25.4

a=curr:qos local sendrecv

a=curr:qos remote sendrecv

a=des:qos mandatory local sendrecv

a=des:qos mandatory remote sendrecv

a=rtpmap:97 AMR

a=fmtp:97 mode-set=0,2,5,7; maxframes=2

a=rtpmap:96 telephone-event

SDP The SDP answer (SDP_A2) contains a set of codecs to be used for the session. The preconditions are indicated as fulfilled.

23-24 200 (OK) response to UPDATE request (CAT-AS to UE#1) see example in table A.4.3-23

CAT-AS forwards the SIP 200 (OK) for the SIP UPDATE request to UE#1.

Table A.4.3-23: 200 (OK) response (CAT-AS to UE#1)

SIP/2.0 200 OK

From:

To:

Call-ID:

Cseq:

Contact:

Content-Type: multipart/mixed; boundary="boundary1"

Content-Length: (…)

–boundary1

Content-Type: application/sdp

Content-Disposition: session

v=0

o=- 2987933615 2987933615 IN IP6 5555::eee:fff:aaa:bbb

s=-

c=IN IP6 5555::eee:fff:aaa:bbb

t=0 0

m=video 3400 RTP/AVP 98

b=AS:75

a=curr:qos local sendrecv

a=curr:qos remote sendrecv

a=des:qos mandatory local sendrecv

a=des:qos mandatory remote sendrecv

a=rtpmap:98 H263

a=fmtp:98 profile-level-id=0

m=audio 3456 RTP/AVP 97 96

b=AS:25.4

a=curr:qos local sendrecv

a=curr:qos remote sendrecv

a=des:qos mandatory local sendrecv

a=des:qos mandatory remote sendrecv

a=rtpmap:97 AMR

a=fmtp:97 mode-set=0,2,5,7; maxframes=2

a=rtpmap:96 telephone-event

–boundary1

Content-Type: application/sdp

Content-Disposition: early-session

v=0

o=- 2987933616 2987933616 IN IP6 5555::ccc:aaa:bbb:acc

s=-

c=IN IP6 5555::ccc:aaa:bbb:acc

t=0 0

m=video 3400 RTP/AVP 98

b=AS:75

a=curr:qos local sendrecv

a=curr:qos remote sendrecv

a=des:qos mandatory local sendrecv

a=des:qos mandatory remote sendrecv

a=rtpmap:98 H263

a=fmtp:98 profile-level-id=0

m=audio 3456 RTP/AVP 97

b=AS:25.4

a=curr:qos local sendrecv

a=curr:qos remote sendrecv

a=des:qos mandatory local sendrecv

a=des:qos mandatory remote sendrecv

a=rtpmap:97 AMR

a=fmtp:97 mode-set=0,2,5,7; maxframes

–boundary1

early SDP The early-session SDP answer (early SDP_A2) contains a set of codecs supported by UE#1 to be used for CAT. The early-session SDP content is based on information received from the MRF. The preconditions are indicated as fulfilled.

25-26 180 (Ringing) response to INVITE request (UE#2 to CAT-AS)

The called party is alerted. UE#2 sends a SIP 180 (Ringing) provisional response for the INVITE request towards UE#1.

The CAT-AS terminates the provisional response.

The CAT-AS instructs the MRF to play CAT media.

27-28 200 (OK) response to INVITE request (UE#2 to CAT-AS)

The called party answers the call. UE#2 sends a SIP 200 (OK) final response for the SIP INVITE request towards UE#1.

The CAT-AS instructs the MRF to stop CAT media.

29-30 200 (OK) response to INVITE request (CAT-AS to UE#1)

The CAT-AS forwards the SIP 200 (OK) response to UE#1.

A regular session is established between UE#1 and UE#2.

The early session between UE#1 and the CAT-AS is terminated.

31-32 ACK request (UE#1 to UE#2)

UE#1 sends a SIP ACK request, which acknowledges the 200 (OK) final response, to UE#2.

A.4.4 CAT when UE#1 has resources available while UE#2 does not have required resources available

Figure A.4.4-1: CAT, UE#2 does not have resources available

1-2 INVITE request (UE#1 to CAT-AS) see example in table A.4.4-1

UE#1 sends a SIP INVITE request to the intermediate IM CN subsystem.

Table A.4.4-1: INVITE request (UE#1 to S-CSCF)

INVITE tel:+1-212-555-2222 SIP/2.0

Via: SIP/2.0/UDP [5555::aaa:bbb:ccc:ddd]:1357;comp=sigcomp;branch=z9hG4bKnashds7

Max-Forwards: 70

Route: <sip:pcscf1.visited1.net:7531;lr;comp=sigcomp>, <sip:orig@scscf1.home1.net;lr>

P-Preferred-Identity: "John Doe" <sip:user1_public1@home1.net>

P-Access-Network-Info: 3GPP-UTRAN-TDD; utran-cell-id-3gpp=234151D0FCE11

Privacy: none

From: <sip:user1_public1@home1.net>;tag=171828

To: <tel:+1-212-555-2222>

Call-ID: cb03a0s09a2sdfglkj490333

Cseq: 127 INVITE

Recv-Info: infoDtmf

Supported: precondition, 100rel, early-session

Security-Verify: ipsec-3gpp; q=0.1; alg=hmac-sha-1-96; spi-c=98765432; spi-s=87654321; port-c=8642; port-s=7531

Contact: <sip:user1_public1@home1.net;gr=urn:uuid:f81d4fae-7dec-11d0-a765-00a0c91e6bf6> >;+g.3gpp.icsi_ref="urn%3Aurn-7%3gpp-service.ims.icsi.mmtel"

Accept:application/sdp, application/3gpp-ims+xml

Content-Type: application/sdp

Content-Disposition: session

Content-Length: (…)

v=0

o=- 2987933615 2987933615 IN IP6 5555::aaa:bbb:ccc:ddd

s=-

c=IN IP6 5555::aaa:bbb:ccc:ddd

t=0 0

m=video 3400 RTP/AVP 98

b=AS:75

a=curr:qos local sendrecv

a=curr:qos remote none

a=des:qos mandatory local sendrecv

a=des:qos none remote sendrecv

a=rtpmap:98 H263

m=audio 3456 RTP/AVP 97 96

b=AS:25.4

a=curr:qos local sendrecv

a=curr:qos remote none

a=des:qos mandatory local sendrecv

a=des:qos none remote sendrecv

a=rtpmap:97 AMR

a=fmtp:97 mode-set=0,2,5,7; maxframes=2

a=rtpmap:96 telephone-event

Supported: The UE indicates support for preconditions, reliable provisional responses, and early-session SDP.

Recv-Info: The UE indicates willingness to receive DTMF Info Packages in INFO requests.

SDP The SDP offer (SDP_O1) contains a set of codecs supported by UE#1 and desired by the user at UE#1 for this session. The SDP contains an indication that the local preconditions are fulfilled.

2 INVITE request (S-CSCF to CAT-AS)

The S-CSCF forwards the SIP INVITE request to the CAT-AS.

3-4 INVITE request (CAT-AS to UE#2)

The CAT-AS forwards the SIP INVITE request to UE#2.

5-6 183 (Session Progress) provisional response (UE#2 to CAT-AS) see example in table A.4.4-5

UE#2 sends a SIP 183 (Session Progress) provisional response for the INVITE request to the CAT-AS.

Table A.4.4-5: 183 (Session Progress) response (UE#2 to CAT-AS)

SIP/2.0 183 Session Progress

From:

To: <tel:+1-212-555-2222>;tag=6322

Call-ID:

Cseq:

Require: 100rel, precondition

RSeq: 9021

Contact: <sip:user2_public1@home2.net;gr=urn:uuid:2ad8950e-48a5-4a74-8d99-ad76cc7fc74>;+g.3gpp.icsi_ref="urn%3Aurn-7%3gpp-service.ims.icsi.mmtel"

Content-Type: application/sdp

Content-Disposition: session

Content-Length: (…)

v=0

o=- 2987933615 2987933615 IN IP6 5555::eee:fff:aaa:bbb

s=-

c=IN IP6 5555::eee:fff:aaa:bbb

t=0 0

m=video 3400 RTP/AVP 98

b=AS:75

a=curr:qos local sendrecv

a=curr:qos remote sendrecv

a=des:qos mandatory local sendrecv

a=des:qos mandatory remote sendrecv

a=rtpmap:98 H263

a=fmtp:98 profile-level-id=0

a=content:g.3gpp.cat

m=audio 3456 RTP/AVP 97 96

b=AS:25.4

a=curr:qos local sendrecv

a=curr:qos remote sendrecv

a=des:qos mandatory local sendrecv

a=des:qos mandatory remote sendrecv

a=rtpmap:97 AMR

a=fmtp:97 mode-set=0,2,5,7; maxframes=2

a=rtpmap:96 telephone-event

a=content:g.3gpp.cat

7-8 183 (Session Progress) provisional response (CAT-AS to UE#1) see example in table A.4.4-7

The CAT-AS forwards the SIP 183 (Session Progress) provisional response with early-session SDP for CAT to UE#1.

Table A.4.4-7: 183 (Session Progress) response (CAT-AS to UE#1)

SIP/2.0 183 Session Progress

From:

To:

Call-ID:

Cseq:

Require: 100rel, precondition, early-session

RSeq: 9021

Contact:

Content-Type: multipart/mixed; boundary="boundary1"

Content-Length: (…)

–boundary1

Content-Type: application/sdp

Content-Disposition: session

v=0

o=- 2987933615 2987933615 IN IP6 5555::eee:fff:aaa:bbb

s=-

c=IN IP6 6666::eee:fff:aaa:bbb

t=0 0

m=video 3400 RTP/AVP 98

b=AS:75

a=curr:qos local sendrecv

a=curr:qos remote sendrecv

a=des:qos mandatory local sendrecv

a=des:qos mandatory remote sendrecv

a=rtpmap:98 H263

a=fmtp:98 profile-level-id=0

m=audio 3456 RTP/AVP 97 96

b=AS:25.4

a=curr:qos local sendrecv

a=curr:qos remote sendrecv

a=des:qos mandatory local sendrecv

a=des:qos mandatory remote sendrecv

a=rtpmap:97 AMR

a=fmtp:97 mode-set=0,2,5,7; maxframes=2

a=rtpmap:96 telephone-event

–boundary1

Content-Type: application/sdp

Content-Disposition: early-session

v=0

o=- 2987933616 2987933616 IN IP6 5555::ccc:aaa:bbb:acc

s=-

c=IN IP6 5555::ccc:aaa:bbb:acc

t=0 0

m=video 3400 RTP/AVP 98

b=AS:75

a=curr:qos local sendrecv

a=curr:qos remote none

a=des:qos mandatory local sendrecv

a=des:qos mandatory remote sendrecv

a=rtpmap:98 H263

a=fmtp:98 profile-level-id=0

m=audio 3456 RTP/AVP 97

b=AS:25.4

a=curr:qos local sendrecv

a=curr:qos remote none

a=des:qos mandatory local sendrecv

a=des:qos mandatory remote sendrecv

a=rtpmap:97 AMR

a=fmtp:97 mode-set=0,2,5,7; maxframes

–boundary1

early SDP The early-session SDP offer (early SDP_O1) contains a set of codecs to be used for CAT. The local preconditions are indicated as fulfilled.

9-10 PRACK request (UE#1 to CAT-AS) see example in table A.4.4-9

UE#1 sends a SIP PRACK request with early-session SDP answer, which acknowledges the 183 (Session Progress) provisional response, towards UE#2.

Table A.4.4-9: PRACK request (UE#1 to CAT-AS)

PRACK sip:user2_public1@home2.net;gr=urn:uuid:2ad8950e-48a5-4a74-8d99-ad76cc7fc74 SIP/2.0

Via: SIP/2.0/UDP [5555::aaa:bbb:ccc:ddd]:1357;comp=sigcomp;branch=z9hG4bKna234s7

Max-Forwards: 70

Route: <sip:pcscf1.visited1.net:7531;lr;comp=sigcomp>, <sip:orig@scscf1.home1.net;lr>

P-Preferred-Identity: "John Doe" <sip:user1_public1@home1.net>

P-Access-Network-Info: 3GPP-UTRAN-TDD; utran-cell-id-3gpp=234151D0FCE11

Privacy: none

From:

To:

Call-ID:

Cseq: 128 PRACK

Contact:

Content-Type: application/sdp

Content-Disposition: early-session

Content-Length: (…)

v=0

o=- 2987933616 2987933616 IN IP6 5555::aaa:bbb:ccc:ddd

s=-

c=IN IP6 5555::aaa:bbb:ccc:ddd

t=0 0

m=video 3500 RTP/AVP 98

b=AS:75

a=curr:qos local sendrecv

a=curr:qos remote sendrecv

a=des:qos mandatory local sendrecv

a=des:qos none remote sendrecv

a=rtpmap:98 H263

m=audio 3556 RTP/AVP 97

b=AS:25.4

a=curr:qos local sendrecv

a=curr:qos remote sendrecv

a=des:qos mandatory local sendrecv

a=des:qos none remote sendrecv

a=rtpmap:97 AMR

a=fmtp:97 mode-set=0,2,5,7; maxframes

early SDP The early-session SDP answer (early SDP_A1) contains a set of codecs supported by UE#1 to be used for CAT. The preconditions are indicated as fulfilled.

11-12 PRACK request (CAT-AS to UE#2) see example in table A.4.4-11

CAT-AS forwards the SIP PRACK request without early-session SDP answer to UE#2.

Table A.4.4-11: PRACK request (CAT-AS to UE#2)

PRACK sip:user2_public1@home2.net;gr=urn:uuid:2ad8950e-48a5-4a74-8d99-ad76cc7fc74SIP/2.0

Max-Forwards: 66

Privacy:

From:

To:

Call-ID:

Cseq: 128 PRACK

Contact:

Content-Length: 0

13-16 200 (OK) response to PRACK request (UE#2 to UE#1)

UE#2 sends a SIP 200 (OK) response for the SIP PRACK request to UE#1.

17-18 180 (Ringing) response to INVITE request (UE#2 to CAT-AS)

The called party is alerted. UE#2 sends a SIP 180 (Ringing) provisional response for the INVITE request towards UE#1.

The CAT-AS terminates the provisional response.

The CAT-AS instructs the MRF to play CAT media.

19-20 200 (OK) response to INVITE request (UE#2 to CAT-AS)

The called party answers the call. UE#2 sends a SIP 200 (OK) final response for the SIP INVITE request towards UE#1.

The CAT-AS instructs the MRF to stop CAT media.

21-22 200 (OK) response to INVITE request (CAT-AS to UE#1)

The CAT-AS forwards the SIP 200 (OK) response to UE#1.

A regular session is established between UE#1 and UE#2.

The early session between UE#1 and the CAT-AS is terminated.

23-24 ACK request (UE#1 to UE#2)

UE#1 sends a SIP ACK request, which acknowledges the 200 (OK) final response, to UE#2.