7.30 Session Timer / MO Voice Call / Remote end supports but does not use Session Timer / 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

7.30.1 Test Purpose (TP)

(1)

with { UE being registered to IMS and being configured to use Session Timer and preconditions }

ensure that {

when { UE is being made to initiate a voice call }

then { UE sends INVITE for voice call }

}

(2)

with { UE having sent INVITE for voice call and continuing the call setup }

ensure that {

when { UE receives 200 OK for INVITE with timer tag and without Session-Expires }

then { UE sends ACK }

}

(3)

with { UE having sent ACK }

ensure that {

when { 1860 seconds passed without the UE refreshing the session }

then { UE receives BYE and sends 200 OK for BYE }

}

7.30.2 Conformance Requirements

The conformance requirements covered in the present test case are, unless otherwise stated, Rel-15 requirements.

[TS 24.229 clause 5.1.2A.1.1]

A UE supporting RFC 4028 [58], when it receives a 422 (Session Interval Too Small) to an INVITE request where the response contains a Min-SE header field, shall retry the request in accordance with RFC 4028 [58] subclause 7.4.

[TS 24.229 clause 5.2.7.2]

When the P-CSCF receives from the UE an INVITE request, the P-CSCF may require the periodic refreshment of the session to avoid hung states in the P-CSCF. If the P-CSCF requires the session to be refreshed, then the P-CSCF shall apply the procedures described in RFC 4028 [58] clause 8.

NOTE 1: Requesting the session to be refreshed requires support by at least one of the UEs. This functionality cannot automatically be granted, i.e. at least one of the involved UEs needs to support it.

[TS 24.229 clause 5.2.7.3]

When the P-CSCF receives an INVITE request destined for the UE the P-CSCF may require the periodic refreshment of the session to avoid hung states in the P-CSCF. If the P-CSCF requires the session to be refreshed, then the P-CSCF shall apply the procedures described in RFC 4028 [58] clause 8.

NOTE 1: Requesting the session to be refreshed requires support by at least one of the UEs. This functionality cannot automatically be granted, i.e. at least one of the involved UEs needs to support it in order to make it work.

[TS 24.229 clause 5.4.5.3]

If the S-CSCF requested the session to be refreshed periodically, and the S-CSCF got the indication that the session will be refreshed, when the session timer expires, the S-CSCF shall delete all the stored information related to the dialog.

7.30.3 Test description

7.30.3.1 Pre-test conditions

System Simulator:

– 1 NR Cell connected to 5GC, default parameters.

UE:

– UE contains either ISIM and USIM applications or only USIM application on UICC.

– UE is configured to register for IMS after switch on.

– UE is configured to use Session Timer and preconditions.

Preamble:

– UE is in state 1N-A (TS 38.508-1 [21]) and registered to IMS.

7.30.3.2 Test procedure sequence

Table 7.30.3.2-1: Main Behaviour

St

Procedure

Message Sequence

TP

Verdict

U – S

Message

1

UE is made to attempt an IMS voice call.

–

–

2-7

Steps 2-7 of generic procedure specified in Table 4.9.15.2.2-1 of TS 38.508-1 [21] are performed.

–

–

–

EXCEPTION: In parallel with Step 8, parallel behaviour defined in table 7.30.3.2-2 takes place

–

–

–

–

8

UE sends INVITE indicating support for Session Timer, with either the Session-Expires value set to 1800 or no Session-Expires header.

–>

INVITE

1

P

9-12

Steps 2-5 of Annex A.4.1a happen.

–

–

12A

Step 10 of generic procedure specified in Table 4.9.15.2.2-1 of TS 38.508-1 [21] is performed.

–

–

–

–

–

EXCEPTION: In parallel to steps 12B and 12C below, step 13 occurs.

–

–

–

–

12B-12C

Steps 11-12 of generic procedure specified in Table 4.9.15.2.2-1 of TS 38.508-1 [21] are performed.

–

–

–

–

13-17

Steps 6-10 of Annex A.4.1a happen.

–

–

18

SS sends 200 OK for INVITE, with timer tag in Supported headers but without Session-Expires header.

<–

200 OK

19

UE sends ACK.

–>

ACK

2

P

20

SS sends BYE to release the call 1860 seconds after step 19.

(Step 1 of Annex A.8)

<–

BYE

3

P

21

UE sends 200 OK for BYE.

(Step 2 of Annex A.8)

–>

200 OK

3

P

Table 7.30.3.2-2: Parallel behaviour

St

Procedure

Message Sequence

TP

Verdict

U – S

Message

1

The UE transmits an RRCReconfigurationComplete message.

–>

NR RRC: RRCReconfigurationComplete

–

–

7.30.3.3 Specific message contents

Table 7.30.3.3-1: INVITE (step 8, table 7.30.3.2-1)

Derivation Path: Annex A.4.1a, Step 1, with A26 as additional condition.

Header/param

Cond

Value/remark

Rel

Reference

Session-Expires

(if present)

RFC 4028 [37]

delta-seconds

1800

refresher

uac (if present)

Table 7.30.3.3-2: 200 OK (step 18, table 7.30.3.2-1)

Derivation Path: Annex A.4.1a, Step 11

Header/param

Cond

Value/remark

Rel

Reference

Supported

timer

RFC 4028 [37]