7.34 Session Timer / MT Voice Call / Remote end does not support 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

7.34.1 Test Purpose (TP)

(1)

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

ensure that {

when { UE receives INVITE for voice call without support for Session Timer }

then { UE continues setup of voice call and finally sends 200 OK for INVITE with Session-Expires being 1800 and setting refresher to uas }

}

(2)

with { Call having been set up }

ensure that {

when { 900 seconds have passed }

then { UE sends UPDATE to refresh the session }

}

7.34.2 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.

7.34.3 Test description

7.34.3.1 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.

7.34.3.2 Test procedure sequence

Table 7.34.3.2-1: Main Behaviour

St

Procedure

Message Sequence

TP

Verdict

U – S

Message

1-8

Steps 1-8 of generic procedure specified in Table 4.9.16.2.2-1 of TS 38.508-1 [21] are performed.

–

–

–

–

9

SS sends INVITE without support for Session-Timer.

<–

INVITE

–

–

10-13

Steps 2-5 of Annex A.5.1 happen.

–

–

–

–

13A-13C

Steps 10-12 of generic procedure specified in Table 4.9.16.2.2-1 of TS 38.508-1 [21] are performed.

–

–

–

–

14-18A

Steps 6-10A of Annex A.5.1 happen.

–

–

–

–

19

UE sends 200 OK for INVITE with Session-Expires value set to 1800 and refresher value set to uas.

–>

200 OK

1

P

20

SS sends ACK.

(Step 12 of Annex A.5.1)

<–

ACK

–

–

21

900 seconds after step 20, UE sends an UPDATE request to refresh the session.

–>

UPDATE

2

P

22

SS sends 200 OK for UPDATE.

<–

200 OK

–

–

23-24

SS releases the call.

(Steps 1-2 of Annex A.8)

–

–

–

–

7.34.3.3 Specific message contents

Table 7.34.3.3-1: INVITE (step 9, table 7.34.3.2-1)

Derivation Path: Annex A.5.1, step 1

Header/param

Cond

Value/remark

Rel

Reference

Allow

INVITE, UPDATE, PRACK, ACK, OPTIONS, CANCEL, BYE

RFC 4028 [37]

Table 7.34.3.3-2: 200 OK (step 19, table 7.34.3.2-1)

Derivation Path: Annex A.5.1, step 11

Header/param

Cond

Value/remark

Rel

Reference

Session-Expires

RFC 4028 [37]

delta-seconds

1800

refresher

uas

Table 7.34.3.3-3: UPDATE (step 21, table 7.34.3.2-1)

Derivation Path: TS 34.229-1 [2], Annex A.2.5, Conditions A3 and A6

Header/param

Cond

Value/remark

Rel

Reference

Supported

timer

RFC 4028 [37]

Session-Expires

RFC 4028 [37]

delta-seconds

1800

refresher

uac

Content-Type

any value if present

RFC 4028 [37]

Table 7.34.3.3-4: 200 OK (step 22, table 7.34.3.2-1)

Derivation Path: TS 34.229-1 [2], Annex A.3.1, Conditions A1 and A10