7.33 Session Timer / MT Voice Call / Remote end chooses UE as refresher / 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

7.33.1 Test Purpose (TP)

(1)

with { UE being registered to IMS and being configured to use Session Timer and being configured to not use preconditions }

ensure that {

when { UE receives INVITE for voice call with Session-Expires value 1800 and refresher set uas and remote UE not supporting UPDATE }

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 { Voice call having been set up }

ensure that {

when { 900 seconds have passed }

then { UE sends re-INVITE to refresh the session }

}

(3)

with { UE having refreshed the session }

ensure that {

when { Another 900 seconds have passed }

then { UE sends another re-INVITE to refresh the session }

}

7.33.2 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.

7.33.3 Test description

7.33.3.1 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

– UE is configured to not use preconditions.

Preamble:

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

7.33.3.2 Test procedure sequence

Table 7.33.3.2-1: 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 with Session-Expires value set to 1800 and refresher set to uas.

<–

INVITE

–

–

10-13

Steps 2-5 of Annex A.5.2 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.

–

–

–

–

14-17

Steps 6-8A of Annex A.5.2 happen.

–

–

–

–

18

Void

–

–

–

–

19

UE send 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 10 of Annex A.5.2)

<–

ACK

–

–

21

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

–>

INVITE

2

P

22

SS sends 200 OK for INVITE.

<–

200 OK

–

–

23

UE sends ACK.

–>

ACK

–

–

24

900 seconds after step 23, UE sends an INVITE request to refresh the session.

–>

INVITE

3

P

25

SS sends 200 OK for INVITE.

<–

200 OK

–

–

26

UE sends ACK.

–>

ACK

–

–

27-28

SS releases the call.

(Steps 1-2 of Annex A.8)

–

–

–

–

7.33.3.3 Specific message contents

Table 7.33.3.3-1: INVITE (step 9, table 7.33.3.2-1)

Derivation Path: Step 1 of Annex A.5.2

Header/param

Cond

Value/remark

Rel

Reference

Allow

INVITE, ACK, OPTIONS, CANCEL, BYE

RFC 3261 [6]

Session-Expires

RFC 4028 [37]

delta-seconds

1800

refresher

uas

Table 7.33.3.3-2: 200 OK (step 19, table 7.33.3.2-1)

Derivation Path: Annex A.5.2, Step 9

Header/param

Cond

Value/remark

Rel

Reference

Session-Expires

RFC 4028 [37]

delta-seconds

1800

refresher

uas

Table 7.33.3.3-3: INVITE (steps 21 and 24, table 7.33.3.2-1)

Derivation Path: TS 34.229-1 [2], Annex A.2.1, Conditions A32, A26 and A28

Header/param

Cond

Value/remark

Rel

Reference

Session-Expires

RFC 4028 [37]

delta-seconds

1800

refresher

uac

Content-Type

RFC 3261 [6]

media-type

application/sdp

Content-Length

RFC 3261 [6]

value

length of message-body

Message-body

Same SDP message as the last SDP message sent by the UE in the 183 Session Progress at step 11; the session version in the origin shall not be incremented.

RFC 4566 [38]

Table 7.33.3.3-4: 200 OK (steps 22 and 25, table 7.33.3.2-1)

Derivation Path: TS 34.229-1 [2], Annex A.3.1, Conditions A2, A11, A20 and A22

Header/param

Cond

Value/remark

Rel

Reference

Require

timer

RFC 4028 [37]

Session-Expires

RFC 4028 [37]

delta-seconds

1800

refresher

uac

Content-Type

RFC 3261 [6]

media-type

application/sdp

Content-Length

RFC 3261 [6]

Value

length of message-body

Message-body

Same SDP message as the last SDP message sent by the SS in the INVITE at step 9; the session version in the origin shall not be incremented