7.29 Session Timer / MO 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

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

7.29.1 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 the voice call }

then { UE sends INVITE for voice call }

}

(2)

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

ensure that {

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

then { UE sends ACK }

}

(3)

with { UE having sent ACK }

ensure that {

when { 900 seconds have passed }

then { UE sends UPDATE to refresh the session }

}

(4)

with { UE having sent received 200 OK for UPDATE }

ensure that {

when { Another 900 seconds have passed }

then { UE sends UPDATE to refresh the session }

}

7.29.2 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.

7.29.3 Test description

7.29.3.1 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.

7.29.3.2 Test procedure sequence

Table 7.29.3.2-1: 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 7.27.3.2-2 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, without timer tag in Supported and Require headers and without Session-Expires header.	<–	200 OK
19	UE sends ACK.	–>	ACK	2	P
20	900 seconds after step 19, UE sends an UPDATE request to refresh the session.	–>	UPDATE	3	P
21	SS sends 200 OK for UPDATE, without timer tag in Supported and Require headers and without Session-Expires header.	<–	200 OK
22	900 seconds after step 21, UE sends an UPDATE request to refresh the session.	–>	UPDATE	4	P
23	SS sends 200 OK for UPDATE, without timer tag in Supported and Require headers and without Session-Expires header.	<–	200 OK
24-25	SS releases the call. (Steps 1-2 of Annex A.8)	–	–

Table 7.29.3.2-2: Parallel behaviour

St	Procedure	Message Sequence		TP	Verdict
		U – S	Message
1	The UE transmits an RRCReconfigurationComplete message.	–>	NR RRC: RRCReconfigurationComplete	–	–

7.29.3.3 Specific message contents

Table 7.29.3.3-1: INVITE (step 8, table 7.29.3.2-1)

Derivation Path: Annex A.4.1a 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 7.29.3.3-2: 183 Session Progress (step 10, table 7.29.3.2-1)

Derivation Path: Annex A.4.1a, step 3
Header/param	Cond	Value/remark	Rel	Reference
Allow		INVITE, UPDATE, PRACK, ACK, OPTIONS, CANCEL, BYE		RFC 4028 [37]

Table 7.29.3.3-3: 200 OK (step 18, table 7.29.3.2-1)

Derivation Path: Annex A.4.1a, step 11
Header/param	Cond	Value/remark	Rel	Reference
Allow		INVITE, UPDATE, PRACK, ACK, OPTIONS, CANCEL, BYE		RFC 4028 [37]

Table 7.29.3.3-4: UPDATE (steps 20 and 22, table 7.29.3.2-1)

Derivation Path: TS 34.229-1 [2], Table in Annex A.2.5, Conditions A1 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]