A.15 MTSI MO Video Call / 5GS

34.229-53GPPInternet Protocol (IP) multimedia call control protocol based on Session Initiation Protocol (SIP) and Session Description Protocol (SDP)Part 5: Protocol conformance specification using 5G System (5GS)Release 16TSUser Equipment (UE) conformance specification

A.15.1 MTSI MO Video Call / with preconditions / 5GS

Expected sequence

Step

Direction

Message

Comment

UE

SS

1

🡪

INVITE

UE sends INVITE with the first SDP offer.

2

🡨

100 Trying

SS sends a 100 Trying provisional response.

3

🡨

183 Session Progress

SS sends an SDP answer.

4

🡪

PRACK

UE acknowledges reception of 183 Session Progress.

5

🡨

200 OK

SS responds to PRACK.

6

🡪

UPDATE

UE sends a second SDP offer in an UPDATE request.

7

🡨

200 OK

SS responds to UPDATE.

8

🡨

180 Ringing

SS sends 180 Ringing reliably.

9

🡪

PRACK

UE acknowledges reception of 180 Ringing.

10

🡨

200 OK

SS responds to PRACK.

11

🡨

200 OK

SS responds to INVITE.

12

🡪

ACK

UE acknowledges.

Specific Message Contents

INVITE (Step 1)

Use the default message "INVITE for MO Call Setup" in Annex A.2.1 of TS 34.229-1 [2] applying conditions A1, A3, A4, A28, A29, A30, and A31, and with the following exceptions:

Header/param

Value/Remark

Supported

option-tag

precondition

Message-body

The following SDP types and values.

Session description:

v=0

o=(username) (sess-id) (sess-version) IN (addrtype) (unicast-address for UE)

s=(session name)

c=IN (addrtype) (connection-address for UE) [Note 1]

b=AS: (bandwidth-value)

Time description:

t= (start-time) (stop-time)

Media description:

m=audio (transport port) RTP/AVP (fmt)

c=IN (addrtype) (connection-address for UE) [Note 1]

b=AS: (bandwidth-value)

b=RS: (bandwidth-value) [Note 2]

b=RR: (bandwidth-value) [Note 2]

Attributes for media:

a=rtpmap: (payload type) EVS/16000 [Note 3, 9, 10, 12]

a=fmtp: (format) br=5.9-13.2; bw=nb-swb; max-red= (att-field) [Note 4, 5, 10, 12]

a=rtpmap: (payload type) EVS/16000 [Note 3, 9, 10, 13]

a=fmtp: (format) br=5.9-24.4; bw=nb-swb; max-red= (att-field) [Note 4, 5, 10, 13]

a=rtpmap: (payload type) EVS/16000 [Note 3, 9, 10, 14]

a=fmtp: (format) br=13.2; bw=swb; max-red= (att-field) [Note 4, 5, 10, 14]

a=rtpmap: (payload type) EVS/16000 [Note 3, 9, 10, 15]

a=fmtp: (format) br=9.6-13.2; bw=swb; max-red= (att-field) [Note 4, 5, 10, 15]

a=rtpmap: (payload type) EVS/16000 [Note 3, 9, 10, 16]

a=fmtp: (format) br=9.6-24.4; bw=swb; max-red= (att-field) [Note 4, 5, 10, 16]

a=rtpmap: (payload type) EVS/16000 [Note 3, 9, 11]

a=fmtp: (format) bw=nb-swb; max-red= (att-field) [Note 4, 5, 11]

a=rtpmap: (payload type) AMR-WB/16000 [Note 3, 9]

a=fmtp: (format) mode-change-capability=2; max-red= (att-field) [Note 4, 6]

a=rtpmap: (payload type) telephone-event/16000

a=fmtp: (format)

a=rtpmap: (payload type) AMR/8000 [Note 3, 9]

a=fmtp: (format) mode-change-capability=2; max-red= (att-field) [Note 4, 6]

a=rtpmap: (payload type) telephone-event/8000

a=fmtp: (format)

a=ecn-capable-rtp: leap ect=0 [Note 7]

a=rtcp-fb:* nack ecn [Note 7]

a=rtcp-xr:ecn-sum [Note 7]

a=rtcp-rsize [Note 7]

a=ptime:20

a=maxptime:240

Attributes for media security mechanism:

a=3ge2ae: requested [Note 8]

a=crypto:1 AES_CM_128_HMAC_SHA1_80inline:WVNfX19zZW1jdGwgKCkgewkyMjA7fQp9CnVubGVz|2^20|

1:4FEC_ORDER=FEC_SRTP" [Note 8]

Attributes for preconditions:

a=curr:qos local none

a=curr:qos remote none

a=des:qos mandatory local sendrecv

a=des:qos optional remote sendrecv

Media description:

m=video (transport port) RTP/AVPF (fmt) or RTP/AVP (fmt) [Note 17]

c=IN (addrtype) (connection-address for UE) [Note 1]

b=AS: (bandwidth-value)

b=RS: (bandwidth-value)

b=RR: (bandwidth-value)

Attributes for media:

a=tcap:1 RTP/AVPF [Note 17]

a=pcfg:1 t=1 [Note 17]

a=rtpmap: (payload type) H265/90000

a=fmtp: (format) profile-id=1;level-id=(att-field)

a=rtpmap: (payload type) H264/90000

a=fmtp: (format) profile-level-id= (att-field)

Attributes for preconditions:

a=curr:qos local none

a=curr:qos remote none

a=des:qos mandatory local sendrecv

a=des:qos optional remote sendrecv

Note 1: At least one "c=" field shall be present.

Note 2: The RR value shall be greater than 0. The RS value can be any value.

Note 3: The channel number shall be "/1" or omitted.

Note 4: The max-red values from 0 to 220 are allowed.

Note 5: The parameters dtx, dtx-recv and evs-mode-switch shall not be present.

Note 6: The parameters mode-set, mode-change-period, mode-change-neighbor, crc, robust-sorting and interleaving shall not be included.

Note 7: Attributes for ECN Capability may be present if the UE supports Explicit Congestion Notification.

Note 8: Attributes for media plane security are present if the use of end-to-access-edge security is supported by UE.

Note 9: The ordering of payload types shall be as listed, i.e., EVS before AMR-WB before AMR according to NG.114 [31].

Note 10: The EVS payload type shall carry at least one of the five EVS configurations according to NG.114 [31] clause 3.2.2.3. In addition, if there is no further EVS payload type according to the criteria of Note 11, the following rules shall be checked:
IF the first EVS payload type is configuration B0 or B1 THEN
there shall be a second EVS payload type with configuration A1
ELSE IF the first EVS payload type is configuration B2 THEN

there shall be a second EVS payload type with configuration A2
(NOTE: if the first EVS payload type is configuration A1 or A2 there does not need to be any further EVS payload type)

Note 11: Further EVS payload type according to NG.114 [31] clause 3.2.2.3 with bandwidth up to super-wideband, no br parameter and no mode-set parameter.

Note 12: EVS payload type with EVS Configuration A1 (NG.114 [31] clause 3.2.2.3).

Note 13: EVS payload type with EVS Configuration A2 (NG.114 [31] clause 3.2.2.3).

Note 14: EVS payload type with EVS Configuration B0 (NG.114 [31] clause 3.2.2.3).

Note 15: EVS payload type with EVS Configuration B1 (NG.114 [31] clause 3.2.2.3).

Note 16: EVS payload type with EVS Configuration B2 (NG.114 [31] clause 3.2.2.3).

Note 17: The tcap/pcfg attributes are present if RTP/AVP is present on the m line.

100 Trying (Step 2)

Use the default message "100 Trying for INVITE" in Annex A.2.2 of TS 34.229-1 [2] applying condition A1.

183 Session Progress (Step 3)

Use the default message "183 Session Progress for INVITE" in Annex A.2.3 of TS 34.229-1 [2] applying condition A1, and with the following exceptions:

Header/param

Value/Remark

Require

option-tag

precondition

Message-body

The following SDP types and values.

Session description:

v=0

o=- 1111111111 1111111111 IN (addrtype) (unicast-address for SS)

s=-

c=IN (addrtype) (connection-address for SS)

b=AS:65

Time description:

t=0 0

Media description:

m=audio (transport port) RTP/AVP (fmt) [Note 1, 2]

b=AS:65

b=RS: (bandwidth-value) [Note 3]

b=RR: (bandwidth-value) [Note 3]

Attributes for media:

a=rtpmap: (payload type) EVS/16000/1 [Note 1, 8]

a=fmtp: (format) br=13.2; bw=swb; mode-set=0,1,2; max-red=220 [Note 8]

a=rtpmap: (payload type) EVS/16000/1 [Note 1, 9]

a=fmtp: (format) br=5.9-13.2; bw=nb-swb; mode-set=0,1,2; max-red=220 [Note 9]

a=ecn-capable-rtp: leap ect=0 [Note 6]

a=rtcp-fb:* nack ecn [Note 6]

a=rtcp-xr:ecn-sum [Note 6]

a=ptime:20

a=maxptime:240

Attributes for media security mechanism:

a=3ge2ae: requested [Note 7]

a=crypto:1 AES_CM_128_HMAC_SHA1_80inline:PS1uQCVeeCFCanVmcjkpPywjNWhcYD0mXXtxaVBR|2^20|1:4 [Note 7]

Attributes for preconditions:

a=curr:qos local none

a=curr:qos remote none

a=des:qos mandatory local sendrecv

a=des:qos mandatory remote sendrecv

a=conf:qos remote sendrecv

Media description:

m=video (transport port) RTP/AVPF (fmt) [Note 1]

b=AS: (bandwidth-value) [Note 1]

b=RS: (bandwidth-value) [Note 1]

b=RR: (bandwidth-value) [Note 1]

Attributes for media:

a=acfg:1 t=1 [Note 10]

a=rtpmap: (payload type) H265/90000 [Note 1]

a=fmtp: (format) (format specific parameters) [Note 1]

Attributes for preconditions:

a=curr:qos local none

a=curr:qos remote none

a=des:qos mandatory local sendrecv

a=des:qos mandatory remotel sendrecv

a=des:qos remote sendrecv

Note 1: The values for fmt, bandwidth, payload type, format and format specific parameters are copied from step 1.

Note 2: Transport port is the port number of the SS (see RFC 3264 clause 6).

Note 3: The bandwidth-value is copied from step 1.

Note 4: Void

Note 5: Void

Note 6: Attributes for ECN Capability are present if the UE supports Explicit Congestion Notification.

Note 7: Attributes for media plane security are present if the use of end-to-access-edge security is supported by UE.

Note 8: This EVS configuration is sent if UE sent it as the first of its EVS configurations in INVITE.

Note 9: This EVS configuration is sent if UE did not send "br=13.2; bw=swb" as the first of its EVS configurations in INVITE.

Note 10: Present if tcap/pcfg attributes were included in step 1

PRACK (Step 4)

Use the default message "PRACK" in Annex A.2.4 of TS 34.229-1 [2] applying conditions A1 and A7.

200 OK for PRACK (Step 5)

Use the default message "200 OK for other requests than REGISTER or SUBSCRIBE" in Annex A.3.1 of TS 34.229-1 [2] applying conditions A10 and A22.

UPDATE (Step 6)

Use the default message "UPDATE" in Annex A.2.5 of TS 34.229-1 [2] applying conditions A1 and A6, and with the following exceptions:

Header/param

Value/Remark

Require

option-tag

precondition

Message-body

The following SDP types and values shall be present.

Session description:

v=0

o=(username) (sess-id) (sess-version) IN (addrtype) (unicast-address for UE) [Note 2]

s=(session name)

c=IN (addrtype) (connection-address for UE) [Note 1]

b=AS: (bandwidth-value)

Time description:

t=0 0

Media description:

m=audio (transport port) RTP/AVP (fmt) [Note 3]

c=IN (addrtype) (connection-address for UE) [Note 1]

b=AS: (bandwidth-value)

b=RS: (bandwidth-value)

b=RR: (bandwidth-value)

Attributes for media:

a=rtpmap: (payload type) EVS/16000 [Note 3] [Note 5]

a=fmtp: (format) [Note 3] [Note 4]

Attributes for preconditions:

a=curr:qos local sendrecv

a=curr:qos remote none

a=des:qos mandatory local sendrecv

a=des:qos optional remote sendrecv or a=des:qos mandatory remote sendrecv

Media description:

m=video (transport port) RTP/AVPF (fmt)

c=IN (addrtype) (connection-address for UE) [Note 1]

b=AS: (bandwidth-value)

b=RS: (bandwidth-value)

b=RR: (bandwidth-value)

Attributes for media:

a=rtpmap: (payload type) H265/90000

a=fmtp: (format) profile-id=1;level-id=(att-field)

Attributes for preconditions:

a=curr:qos local sendrecv

a=curr:qos remote none

a=des:qos mandatory local sendrecv

a=des:qos optional remote sendrecv or a=des:qos mandatory remote sendrecv

Note 1: At least one "c=" field shall be present.

Note 2: "o=" line identical to previous SDP sent by UE except that sess-version is incremented by one

Note 3: The value for fmt, payload type and format is not checked

Note 4: Parameters for the codec are not checked

Note 5: The channel number shall be "/1" or omitted.

200 OK for UPDATE (Step 7)

Use the default message "200 OK for other requests than REGISTER or SUBSCRIBE" in Annex A.3.1 of TS 34.229-1 [2] applying conditions A1, A10 and A22, and with the following exceptions:

Header/param

Value/remark

Require

option-tag

precondition

Content-Type

media-type

application/sdp

Content-Length

value

length of message-body

Message-body

SDP body of the 200 response copied from the received UPDATE and modified as follows:

– IP address on "c=" lines and transport port on "m=" lines changed to indicate to which IP address and port the UE should start sending the media;

– "o=" line identical to previous SDP sent by SS except that sess-version is incremented;

– Attributes for preconditions: a=curr:qos remote sendrecv

180 Ringing (Step 8)

Use the default message "180 Ringing for INVITE" in Annex A.2.6 of TS 34.229-1 [2] applying conditions A1 and A3.

PRACK (Step 9)

Use the default message "PRACK" in Annex A.2.4 of TS 34.229-1 [2] applying conditions A1 and A7.

200 OK for PRACK (Step 10)

Use the default message "200 OK for other requests than REGISTER or SUBSCRIBE" in Annex A.3.1 of TS 34.229-1 [2] applying condition A10.

200 OK for INVITE (Step 11)

Use the default message "200 OK for other requests than REGISTER or SUBSCRIBE" in Annex A.3.1 of TS 34.229-1 [2] applying conditions A1, A10, and A19.

ACK (Step 12)

Use the default message "ACK" in Annex A.2.6 of TS 34.229-1 [2] applying conditions A1 and A3.

A.15.2 MTSI MO Video Call / without preconditions / 5GS

Expected sequence

Step

Direction

Message

Comment

UE

SS

1

🡪

INVITE

UE sends INVITE with the first SDP offer.

2

🡨

100 Trying

SS sends a 100 Trying provisional response.

3

🡨

183 Session Progress

SS sends an SDP answer.

4

🡪

PRACK

UE acknowledges reception of 183 Session Progress.

5

🡨

200 OK

SS responds to PRACK.

6

🡨

180 Ringing

SS sends 180 Ringing reliably.

7

🡪

PRACK

UE acknowledges reception of 180 Ringing.

8

🡨

200 OK

SS responds to PRACK.

9

🡨

200 OK

SS responds to INVITE.

10

🡪

ACK

UE acknowledges.

Specific Message Contents

INVITE (Step 1)

Use the default message "INVITE for MO Call Setup" in Annex A.2.1 of TS 34.229-1 [2] applying conditions A1, A3, A4, A28, A29, A30, and A31, and with the following exceptions:

Header/param

Value/Remark

Supported

option-tag

precondition – option tag not present
Note: this does not affect any other option tags in the Supported header as for instance prescribed in TS 34.229-1 [2] Annex A.2.1

Message-body

The following SDP types and values.

Session description:

v=0

o=(username) (sess-id) (sess-version) IN (addrtype) (unicast-address for UE)

s=(session name)

c=IN (addrtype) (connection-address for UE) [Note 1]

b=AS: (bandwidth-value)

Time description:

t= (start-time) (stop-time)

Media description:

m=audio (transport port) RTP/AVP (fmt)

c=IN (addrtype) (connection-address for UE) [Note 1]

b=AS: (bandwidth-value)

b=RS: (bandwidth-value) [Note 2]

b=RR: (bandwidth-value) [Note 2]

Attributes for media:

a=rtpmap: (payload type) EVS/16000 [Note 3, 9, 10, 12]

a=fmtp: (format) br=5.9-13.2; bw=nb-swb; max-red= (att-field) [Note 4, 5, 10, 12]

a=rtpmap: (payload type) EVS/16000 [Note 3, 9, 10, 13]

a=fmtp: (format) br=5.9-24.4; bw=nb-swb; max-red= (att-field) [Note 4, 5, 10, 13]

a=rtpmap: (payload type) EVS/16000 [Note 3, 9, 10, 14]

a=fmtp: (format) br=13.2; bw=swb; max-red= (att-field) [Note 4, 5, 10, 14]

a=rtpmap: (payload type) EVS/16000 [Note 3, 9, 10, 15]

a=fmtp: (format) br=9.6-13.2; bw=swb; max-red= (att-field) [Note 4, 5, 10, 15]

a=rtpmap: (payload type) EVS/16000 [Note 3, 9, 10, 16]

a=fmtp: (format) br=9.6-24.4; bw=swb; max-red= (att-field) [Note 4, 5, 10, 16]

a=rtpmap: (payload type) EVS/16000 [Note 3, 9, 11]

a=fmtp: (format) bw=nb-swb; max-red= (att-field) [Note 4, 5, 11]

a=rtpmap: (payload type) AMR-WB/16000 [Note 3, 9]

a=fmtp: (format) mode-change-capability=2; max-red= (att-field) [Note 4, 6]

a=rtpmap: (payload type) telephone-event/16000

a=fmtp: (format)

a=rtpmap: (payload type) AMR/8000 [Note 3, 9]

a=fmtp: (format) mode-change-capability=2; max-red= (att-field) [Note 4, 6]

a=rtpmap: (payload type) telephone-event/8000

a=fmtp: (format)

a=ecn-capable-rtp: leap ect=0 [Note 7]

a=rtcp-fb:* nack ecn [Note 7]

a=rtcp-xr:ecn-sum [Note 7]

a=rtcp-rsize [Note 7]

a=ptime:20

a=maxptime:240

Attributes for media security mechanism:

a=3ge2ae: requested [Note 8]

a=crypto:1 AES_CM_128_HMAC_SHA1_80inline:WVNfX19zZW1jdGwgKCkgewkyMjA7fQp9CnVubGVz|2^20|

1:4FEC_ORDER=FEC_SRTP" [Note 8]

Attributes for preconditions: not present

Media description:

m=video (transport port) RTP/AVPF (fmt) or RTP/AVP (fmt) [Note 17]

c=IN (addrtype) (connection-address for UE) [Note 1]

b=AS: (bandwidth-value)

b=RS: (bandwidth-value)

b=RR: (bandwidth-value)

Attributes for media:

a=tcap:1 RTP/AVPF [Note 17]

a=pcfg:1 t=1 [Note 17]

a=rtpmap: (payload type) H265/90000

a=fmtp: (format) profile-id=1;level-id=(att-field)

a=tcap:1 RTP/AVPF [Note 17]

a=pcfg:1 t=1 [Note 17]

a=rtpmap: (payload type) H264/90000

a=fmtp: (format) profile-level-id= (att-field)

Attributes for preconditions: not present

Note 1: At least one "c=" field shall be present.

Note 2: The RR value shall be greater than 0. The RS value can be any value.

Note 3: The channel number shall be "/1" or omitted.

Note 4: The max-red values from 0 to 220 are allowed.

Note 5: The parameters dtx, dtx-recv and evs-mode-switch shall not be present.

Note 6: The parameters mode-set, mode-change-period, mode-change-neighbor, crc, robust-sorting and interleaving shall not be included.

Note 7: Attributes for ECN Capability may be present if the UE supports Explicit Congestion Notification.

Note 8: Attributes for media plane security are present if the use of end-to-access-edge security is supported by UE.

Note 9: The ordering of payload types shall be as listed, i.e., EVS before AMR-WB before AMR according to NG.114 [31].

Note 10: The EVS payload type shall carry at least one of the five EVS configurations according to NG.114 [31] clause 3.2.2.3. In addition, if there is no further EVS payload type according to the criteria of Note 11, the following rules shall be checked:
IF the first EVS payload type is configuration B0 or B1 THEN
there shall be a second EVS payload type with configuration A1
ELSE IF the first EVS payload type is configuration B2 THEN

there shall be a second EVS payload type with configuration A2
(NOTE: if the first EVS payload type is configuration A1 or A2 there does not need to be any further EVS payload type)

Note 11: Further EVS payload type according to NG.114 [31] clause 3.2.2.3 with bandwidth up to super-wideband, no br parameter and no mode-set parameter.

Note 12: EVS payload type with EVS Configuration A1 (NG.114 [31] clause 3.2.2.3).

Note 13: EVS payload type with EVS Configuration A2 (NG.114 [31] clause 3.2.2.3).

Note 14: EVS payload type with EVS Configuration B0 (NG.114 [31] clause 3.2.2.3).

Note 15: EVS payload type with EVS Configuration B1 (NG.114 [31] clause 3.2.2.3).

Note 16: EVS payload type with EVS Configuration B2 (NG.114 [31] clause 3.2.2.3).

Note 17: The tcap/pcfg attributes are present if RTP/AVP is present on the m line.

100 Trying (Step 2)

Use the default message "100 Trying for INVITE" in Annex A.2.2 of TS 34.229-1 [2] applying condition A2.

183 Session Progress (Step 3)

Use the default message "183 Session Progress for INVITE" in Annex A.2.3 of TS 34.229-1 [2] applying condition A3, and with the following exceptions:

Header/param

Value/Remark

Message-body

The following SDP types and values.

Session description:

v=0

o=- 1111111111 1111111111 IN (addrtype) (unicast-address for SS)

s=-

c=IN (addrtype) (connection-address for SS)

b=AS:65

Time description:

t=0 0

Media description:

m=audio (transport port) RTP/AVP (fmt) [Note 1, 2]

b=AS:65

b=RS: (bandwidth-value) [Note 3]

b=RR: (bandwidth-value) [Note 3]

Attributes for media:

a=rtpmap: (payload type) EVS/16000/1 [Note 1, 8]

a=fmtp: (format) br=13.2; bw=swb; mode-set=0,1,2; max-red=220 [Note 8]

a=rtpmap: (payload type) EVS/16000/1 [Note 1, 9]

a=fmtp: (format) br=5.9-13.2; bw=nb-swb; mode-set=0,1,2; max-red=220 [Note 9]

a=ecn-capable-rtp: leap ect=0 [Note 6]

a=rtcp-fb:* nack ecn [Note 6]

a=rtcp-xr:ecn-sum [Note 6]

a=ptime:20

a=maxptime:240

Attributes for media security mechanism:

a=3ge2ae: requested [Note 7]

a=crypto:1 AES_CM_128_HMAC_SHA1_80inline:PS1uQCVeeCFCanVmcjkpPywjNWhcYD0mXXtxaVBR|2^20|1:4 [Note 7]

Media description:

m=video (transport port) RTP/AVPF (fmt) [Note 1]

b=AS: (bandwidth-value) [Note 1]

b=RS: (bandwidth-value) [Note 1]

b=RR: (bandwidth-value) [Note 1]

Attributes for media:

a=acfg:1 t=1 [Note 10]

a=rtpmap: (payload type) H265/90000 [Note 1]

a=fmtp: (format) (format specific parameters) [Note 1]

Note 1: The values for fmt, bandwidth, payload type, format and format specific parameters are copied from step 1.

Note 2: Transport port is the port number of the SS (see RFC 3264 clause 6).

Note 3: The bandwidth-value is copied from step 1.

Note 4: Void

Note 5: Void

Note 6: Attributes for ECN Capability are present if the UE supports Explicit Congestion Notification.

Note 7: Attributes for media plane security are present if the use of end-to-access-edge security is supported by UE.

Note 8: This EVS configuration is sent if UE sent it as the first of its EVS configurations in INVITE.

Note 9: This EVS configuration is sent if UE did not send "br=13.2; bw=swb" as the first of its EVS configurations in INVITE.

Note 10: Present if tcap/pcfg attributes were included in step 1

PRACK (Step 4)

Use the default message "PRACK" in Annex A.2.4 of TS 34.229-1 [2] applying conditions A1 and A7.

200 OK for PRACK (Step 5)

Use the default message "200 OK for other requests than REGISTER or SUBSCRIBE" in Annex A.3.1 of TS 34.229-1 [2] applying conditions A10 and A22.

180 Ringing (Step 6)

Use the default message "180 Ringing for INVITE" in Annex A.2.6 of TS 34.229-1 [2] applying conditions A2 and A14.

PRACK (Step 7)

Use the default message "PRACK" in Annex A.2.4 of TS 34.229-1 [2] applying conditions A1 and A7.

200 OK for PRACK (Step 8)

Use the default message "200 OK for other requests than REGISTER or SUBSCRIBE" in Annex A.3.1 of TS 34.229-1 [2] applying condition A10.

200 OK for INVITE (Step 9)

Use the default message "200 OK for other requests than REGISTER or SUBSCRIBE" in Annex A.3.1 of TS 34.229-1 [2] applying conditions A1, A10, and A19.

ACK (Step 10)

Use the default message "ACK" in Annex A.2.6 of TS 34.229-1 [2] applying conditions A1 and A3.