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
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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:
Specific Message Contents:
REGISTER (Step 1)
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.
REGISTER (Step 3)
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
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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
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