7.32 Session Timer / MT Voice Call / Remote end sends Session-Expires but does not choose 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

Tools: ARFCN - Frequency Conversion for 5G NR/LTE/UMTS/GSM

7.32.1 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 containing timer tag and Session-Expires value 1800 }

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

}

(2)

with { Call having been set up }

ensure that {

when { 900 seconds have passed and UE receives UPDATE to refresh the session }

then { UE sends 200 OK for UPDATE }

}

7.32.2 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.

[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.

7.32.2A Profile Requirements (Informative)

[NG.114 Version 1.0, clause 2.3.9]:

The UE must support and use IETF RFC 4028 [53] as follows:

…

5. if a received SIP INVITE request indicates support of the "timer" option tag, and contains the Session-Expires header field without "refresher" parameter, the UE must include the "refresher" parameter with the value "uac" in the Session-Expires header field of the SIP 2xx response to the SIP INVITE request, and must set the delta-seconds portion of the Session-Expires header field of the SIP 2xx response to the SIP INVITE request to the value indicated in the delta-seconds portion of the Session-Expires header field of the SIP INVITE request.

7.32.3 Test description

7.32.3.1 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.

7.32.3.2 Test procedure sequence

Table 7.32.3.2-1: 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 timer tag set in Supported header and Session-Expires value set to 1800.	<–	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.	–	–
14-18	Steps 6-10 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 uac.	–>	200 OK	1	P
20	SS sends ACK. (Step 12 of Annex A.5.1)	<–	ACK
21	900 seconds after step 19, SS sends an UPDATE request to refresh the session.	<–	UPDATE
22	UE sends 200 OK for UPDATE.	–>	200 OK	2	P
23-24	SS releases the call. (Steps 1-2 of Annex A.8)	–	–

7.32.3.3 Specific message contents

Table 7.32.3.3-1: INVITE (step 9, table 7.32.3.2-1)

Derivation Path: Annex A.5.1, step 1
Header/param	Cond	Value/remark	Rel	Reference
Session-Expires				RFC 4028 [37]
delta-seconds		1800

Table 7.32.3.3-2: 200 OK (step 19, table 7.32.3.2-1)

Derivation Path: Annex A.5.1, step 11
Header/param	Cond	Value/remark	Rel	Reference
Require		timer		RFC 4028 [37]
Session-Expires				RFC 4028 [37]
delta-seconds		1800
refresher		uac

Table 7.32.3.3-3: UPDATE (step 21, table 7.32.3.2-1)

Derivation Path: TS 34.229-1 [2], Annex A.2.5, Condition A3
Header/param	Cond	Value/remark	Rel	Reference
Supported		Timer		RFC 4028 [37]
Session-Expires				RFC 4028 [37]
delta-seconds		1800
refresher		Uac
Content-Type		not present		RFC 4028 [37]

Table 7.32.3.3-4: 200 OK (step 22, table 7.32.3.2-1)

Derivation Path: TS 34.229-1 [2], Annex A.3.1, Conditions A2 and A11
Header/param	Cond	Value/remark	Rel	Reference
Require		timer		RFC 4028 [37]
Session-Expires				RFC 4028 [37]
delta-seconds		1800
refresher		uac