IMS/SIP - GCF IMS相关认证测试如何通过看case procedure来得知哪些field/IE必须带？

在做GCF的IMS测试时，有时遇到IE mismatch或message invalid这样的错误，但是如果打印不全，就不知道到底mismatch在哪里或者哪个IE导致invalid了。有时mismatch的IE太多，就不知道哪个真正matters.

根本方法是查看这个case的详细步骤，看到底哪个IE必须要带，哪个IE不需要。

以IMS emergency registration/call的case 19.5.1为例，现在34.229-1里找到test procedure：

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19.5.1 New initial emergency registration / UE obtains from the serving IP-CAN an IP address different than the IP address used for the emergency registration

Test procedure

applicable for a UE with E-UTRA support (TS 34.229-2 [5] A.18/1)

1-15) UE executes the procedures described in TS 36.508 [94] table 4.5A.4.3-1 steps 1 to 15 for EPS emergency bearer context activation, IMS emergency registration and subsequent IMS emergency speech call establishment with PSAP

16) Call is released on the UE. SS waits for the UE to send a BYE request.

17) SS responds to the BYE request with valid 200 OK response.

Expected sequence

Step	Direction		Message	Comment
	UE	SS
1			User initiates an emergency call
2-10			Steps defined in annex C.20 followed by the steps defined in annex C.22	IMS emergency registration by the UE followed by IMS emergency call setup with PSAP. Referred from 36.508 [94] table 4.5A.4.3-1 for a UE with E-UTRA support.
11			void
12			void
13-17			Steps defined in annex C.32	Make the UE release the call including EPS Bearer Deactivation procedure according to TS 36.508 [94] subclause 4.5A.15.

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测试步骤里提到具体步骤在C.20,C.22,C.32,其中C.20是注册的步骤，我们以C.20为例：

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C.20 Generic Test Procedure for IMS emergency registration

Test procedure:

1) SS waits for the UE to send an initial REGISTER request.

2) The SS responds to the initial REGISTER request with a valid 401 Unauthorized response.

3) The SS waits for the UE to set up a temporary set of security associations and to send another REGISTER request over those security associations.

4) The SS responds to the second REGISTER request with valid 200 OK response, sent over the same temporary set of security associations that the UE used for sending the REGISTER request.

Expected sequence:

Step	Direction		Message	Comment
	UE	SS
1	à		REGISTER	The UE sends initial IMS emergency registration
2	ß		401 Unauthorized	The SS responds with a valid AKAv1-MD5 authentication challenge and security mechanisms supported by the network.
3	à		REGISTER	The UE completes the security negotiation procedures, sets up a temporary set of SAs and uses those for sending another REGISTER with AKAv1-MD5 credentials.
4	ß		200 OK	The SS responds with 200 OK.

Specific Message Contents:

Use the default message “REGISTER” in annex A.1.1 with condition A1 "Initial unprotected REGISTER" and condition A7 “Initial IMS emergency registration” simultaneously applying.

The contents of From and To headers of the REGISTER request shall be according to condition A7.

Use the default message “REGISTER” in annex A.1.1 with condition A2 "Subsequent REGISTER sent over security associations" and condition A7 “Initial IMS emergency registration” simultaneously applying.

The contents of From and To headers of the REGISTER request shall be according to condition A7.

200 OK for REGISTER (Step 4)

Use the default message “200 OK for REGISTER” in annex A.1.3 with condition A3 “Response for an emergency registration”.

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上面提到annexA.1.1以及conditionA1和A7，那什么是with condition？

就是说如果处于A1或A7条件 ----- 也就是if(A1||A7)为true ----- 那么如下表格value/remark这一列对应于A1或A7的内容就得带！

那么，上面那句下划线的内容到底是什么意思呢？

意思是说，如下A.1.1的这张表格是register消息所有可能带的head/param，如果cond这一列标有A1，那么A1满足时，这一行后面的内容就是Initial unprotected Register要带的消息内容，而现在这个case是测emergency，那么同时设为A7的内容也得带！

比方说，contact里的addr-spec这一项，条件为A7， SOS就必须要放在URI, 举个例子：

m: <sip:001010123456789@[3000::2:5866:42b7:3bd6:3024]:5060;sos>;+sip.instance="<urn:gsma:imei:01458400-000900-0>";+cdmaless;+g.3gpp.icsi-ref="urn%3Aurn-7%3A3gpp-service.ims.icsi.mmtel"

各个condition的具体在后面一张表格。

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A.1.1 REGISTER

Header/param	Cond	Value/remark	Rel	Reference
Contact				RFC 3261 [15] RFC 5627 [61]
addr-spec	A1, A3, A14, A15	SIP URI with IP address or FQDN and indicating either an unprotected port selected by the UE or no port at all.
addr-spec	A2	SIP URI with IP address or FQDN and protected server port of UE.
addr-spec feature-param	A7 A4	The SIP URI shall contain the *sos* URI parameter. +g.3gpp.icsi-ref="(comma-separated list of tag-values)” with comma-separated list of tag-values containing at least tag-value urn%3Aurn-7%3A3gpp-service.ims.icsi.mmtel" (see NOTE 2, 5)
feature-param	A6 AND NOT A7	+g.3gpp.smsip
feature-param	A10	video
feature-param		audio Editor’s note: A grace period is granted for the UE to comply with this requirement. At RAN5#74 [February 2017] this note will be removed.
feature-param	A11 AND NOT A7	+g.3gpp.cs2ps-srvcc	Rel-11
feature-param	A12 AND NOT A7	+g.3gpp.cs2ps-srvcc-alerting	Rel-11
feature-param	A13 AND NOT A16	+g.3gpp.accesstype=”cellular2”	Rel-11	RFC 3840 [63]
feature-param	A13 AND A16	+g.3gpp.accesstype=”wlan1”	Rel-11	RFC 3840 [63]
c-p-instance	A5	+sip.instance="<urn:gsma:imei: (gsma-specifier-defined-substring)>” where gsma-specifier-defined-substring shall be the IMEI code of the UE, coded as specified in RFC 7254 [122], without optional parameters	Rel-10	RFC 7254 [122]
Security-Client	A1, A2			RFC 3329 [21] RFC 4835 [124]
				RFC 3329 [21] RFC 4835 [124]
mechanism-name		ipsec-3gpp
algorithm		hmac-sha-1-96
protocol		esp (if present)
mode		trans (if present)
encrypt-algorithm		des-ede3-cbc or aes-cbc or null
spi-c		SPI number of the inbound SA at the protected client port
spi-s		SPI number of the inbound SA at the protected server port
port-c		protected client port
port-s		protected server port
Security-Client	A14, A15	Not Present
From				RFC 3261 [15]
addr-spec	A1	any IMPU within the set of IMPUs on ISIM (when using ISIM; NOTE 3) or public user identity derived from IMSI (when no ISIM available on the UICC)
addr-spec	A2, A15	same public user identity as in initial REGISTER
addr-spec	A3	public user identity derived from IMSI
addr-spec	A7	emergency public user identity (NOTE 4)
addr-spec	A14	IMPU preconfigured in the UE

Condition	Explanation
A1	Initial unprotected REGISTER (IMS security, A.6a/2 3GPP TS 34.229-2 [5])
A2	Subsequent REGISTER sent over security associations (IMS security, A.6a/2 3GPP TS 34.229-2 [5])
A3	REGISTER for the case UE supports GIBA (A.6a/1 3GPP TS 34.229-2 [5])
A4	The UE supports IMS Multimedia Telephony (MTSI) (A.3A/50 3GPP TS 34.229-2 [5])
A5	obtaining and using GRUUs in the Session Initiation Protocol (SIP) (A.4/53 3GPP TS 34.229-2 [5]). Mandatory from Rel-10 onwards.
A6	The UE supports SM-over-IP receiver (A.3A/62 3GPP TS 34.229-2 [5])
A7	Initial unprotected or subsequent REGISTER for emergency registration
A8	UE supports Session-ID (A.12/30 3GPP TS 34.229-2 [5])
A10	UE supports video (A.12/32 3GPP TS 34.229-2 [5])
A11	UE supports CS to PS SRVCC (A.12/40 3GPP TS 34.229-2 [5])
A12	UE supports CS to PS SRVCC in alerting state (A.12/41 3GPP TS 34.229-2 [5])
A13	UE indicates g.3gpp.accesstype media feature tag in REGISTER (A.12/46 3GPP TS 34.229-2 [5])
A14	Initial REGISTER SIP Digest without TLS for Fixed Broadband Access (SIP Digest without TLS, A.6a/5 3GPP TS 34.229-2 [5])
A15	Subsequent REGISTER SIP Digest without TLS for Fixed Broadband Access (SIP Digest without TLS, A.6a/5 3GPP TS 34.229-2 [5])
A16	IMS registration over WLAN

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上面表格在解释A1的时候提到的34.229-2的A.6a/2，就是如下表格里的第二项，对应一个PICS的值，如果这个值在仪器端设为1，那么这个条件就为真。

比如，第二项对应pics值pc_IMS_Sec为true的话，那么上面condition表格里的A1就为true。所以最终都是通过PICS值控制的。

所以测试的时候，如果把该值置为0，仪器就提示该case是ignored，因为A1对应很多基本IE,如果该条件不满足，那么register消息的很多基本内容都没法填，当然没法测case了。

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Table A.6a: Security scheme

Item	Security scheme	Reference	Status	Release	Mnemonic	Support
1	GIBA	24.229 [10]	o.1	Rel-8	pc_IMS_GIBA_Sec
2	IMS security (IMS AKA plus IPsec ESP)	24.229 [10]	o.1	Rel-8	pc_IMS_Sec
3	GBA for XCAP authentication	33.220 [82] 4.5; 33.222 [63]; 24.109 [64]	o.2	Rel-8	pc_HttpGBAAuthentication
4	HTTP Digest for XCAP authentication	RFC 2617 [65]	o.2	Rel-8	pc_HttpDigestAuthentication
5	SIP Digest without TLS	33.203 [12]	o.1	Rel-8
6	SIP Digest with TLS	33.203 [12]	o.1	Rel-8
7	NASS-IMS-bundled authentication	33.203 [12]	o.1	Rel-8
	Conditions/Options
o.1	At least one of these options has to be supported
o.2	At least one of these options has to be supported if the UE supports XCAP

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