C.24 Generic test procedure for SRVCC media removal

34.229-13GPPInternet Protocol (IP) multimedia call control protocol based on Session Initiation Protocol (SIP) and Session Description Protocol (SDP)Part 1: Protocol conformance specificationRelease 16TSUser Equipment (UE) conformance specification

Test procedure:

1) UE sends an re-INVITE request to the SS.

2) SS responds to the INVITE request with a 100 Trying response.

3) SS responds to the INVITE request with a 200 OK.

4) SS waits for the UE to send an ACK to acknowledge receipt of the 200 OK for INVITE.

Expected sequence:

Step

Direction

Message

Comment

UE

SS

1

🡪

INVITE

UE sends INVITE with audio removed.

2

🡨

100 Trying

SS sends a 100 Trying provisional response.

3

🡨

200 OK

SS responds INVITE with 200 OK.

4

🡪

ACK

UE acknowledges.

Specific Message Contents

INVITE (Step 1)

Use the default message “INVITE for MO Call” in annex A.2.1 with condition A5 (re-INVITE within a dialog) and the following exceptions:

Header/param

Value/Remark

Request-Line

Method

Request-URI

SIP-Version

INVITE

Same value as the URI from the Contact header of the original INVITE request as sent by SS

SIP/2.0

Message-body

The following SDP types and values.

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= (start-time) (stop-time)

Media description:

– m=audio 0 RTP/AVP (fmt)

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

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

200 OK (Step 3)

Use the default message “200 OK” in annex A.3.1 with the following exceptions:

Header/param

Value/Remark

Contact

addr-spec

Same value as the URI from the Contact header of the original INVITE request as sent by SS

Content-Type

media-type

application/sdp

Content-Length

value

length of message-body

Message Body

The following SDP types and values:

Session description:

– v=0

o=- 1111111111 (sess-version) IN (addrtype) (unicast-address for SS) [Note 2]

s=-

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

b=AS:37

Time description:

t=0 0

Media description:

– m=audio 0 RTP/AVP (fmt) [Note 3]

Note 1: Void.

Note 2: sess-version incremented by one if SDP changed compared to last SDP sent by SS

Note 3: The value for fmt is copied from step 1

ACK (Step 4)

Use the default message "ACK" in annex A.2.7 with condition A5 and the following exceptions:

Header/param

Cond

Value/remark

Rel

Reference

Request-Line

RFC 3261 [15]

Method

ACK

Request-URI

Same value as the URI from the Contact header of the original INVITE request as sent by SS

SIP-Version

SIP/2.0

To

addr-spec

tag

Same value as used in the INVITE of step 1

Same value as used in the INIVTE of step 1

RFC 3261 [15]

NOTE 1: when A.2.7 refers to "INVITE", the re-INVITE of step 1 is meant.