7.11 MTSI MT Voice call without preconditions at terminating UE and originating UE requiring them / 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

7.11.1 Test Purpose (TP)

(1)

with { UE being registered to IMS and configured to not use preconditions or the UE does not support preconditions }

ensure that {

when { UE receives INVITE for voice call where remote UE requires usage of preconditions }

then { UE rejects INVITE with 420 Bad Extension response }

}

7.11.2 Conformance Requirements

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

[TS 24.229, clause 5.1.4.1]

If an initial INVITE request is received the terminating UE shall check whether the terminating UE requires local resource reservation.

NOTE 1: The terminating UE can decide if local resource reservation is required based on e.g. application requirements, current access network capabilities, local configuration, etc.

During the session initiation, if local resource reservation is required at the terminating UE and the terminating UE supports the precondition mechanism, and:

a) the received INVITE request includes the "precondition" option-tag in the Supported header field or Require header field and the precondition mechanism is enabled as specified in subclause 5.1.5A, the terminating UE shall use the precondition mechanism and shall include a Require header field with the "precondition" option-tag:

– in responses to that INVITE request if those responses include an SDP body;

– in responses to subsequent requests received in-dialog that include an SDP body and include "precondition" option-tag in Supported header field or Require header field; and

– in subsequent requests that include an SDP body, that it sends towards the originating UE during the session initiation;

b) the received INVITE request includes the "precondition" option-tag in the Supported header field, and the precondition mechanism is disabled as specified in subclause 5.1.5A, the terminating UE shall not use the precondition mechanism:

c) the received INVITE request includes the "precondition" option-tag in the Require header field, and the precondition mechanism is disabled as specified in subclause 5.1.5A, the terminating UE shall reject the INVITE request with a 420 (Bad Extension) response; and

d) the received INVITE request does not include the "precondition" option-tag in the Supported header field or Require header field, the terminating UE shall not use the precondition mechanism.

7.11.3 Test description

7.11.3.1 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 not use preconditions or the UE does not support preconditions .

Preamble:

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

7.11.3.2 Test procedure sequence

Table 7.11.3.2-1: 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	Step 1 of A.5.1 happens, with one change: SS sends an INVITE request with a Require header field containing the precondition option-tag.	<–	INVITE
9A	Optional step: UE may send a 100 Trying provisional response.	–>	(Optional) 100 Trying
10	UE sends a 420 Bad Extension response with an Unsupported header field containing the precondition option-tag.	–>	420 Bad Extension	1	P
11	SS acknowledges the reception of 420 Bad Extension.	<–	ACK

7.11.3.3 Specific message contents

Table 7.11.3.3-1: INVITE (step 9, table 7.11.3.2-1)

Derivation Path: Annex A.5.1
Header/param	Cond	Value/remark	Rel	Reference
Require				RFC 3261 [6]
option-tag		precondition

Table 7.11.3.3-2: 100 Trying (step 9A, Table 7.11.3.2-1)

Derivation path: TS 34.229-1 [2], Annex A.2.2, Condition A2

Table 7.11.3.3-3: 420 Bad Extension for INVITE (step 10, table 7.11.3.2-1)

Derivation Path: TS 34.229-1 [2], Annex A.2.25
Header/param	Cond	Value/remark	Rel	Reference
Unsupported				RFC 3261 [6]
option-tag		precondition

Table 7.11.3.3-4: ACK (step 11, Table 7.11.3.2-1)

Derivation path: TS 34.229-1 [2], Annex A.2.7, Conditions A2 and A4