2019独角兽企业重金招聘Python工程师标准>>> 
一般分析方法；
AT层需要搜下如下命令：
ATD+number
AT+CHUP
AT+ESRVCC
+ECPI
+ESIPCPI
AT+CLCC
Modem层的分析方法：
对于这种通话自动挂断问题,首先得确定CC流程是否完整。
如果CC流程不完整，就需要查看它的承载RR层
//这个流程就是通话的大致流程。setup就是发起通话.
OTA (PCORE) 1125225 738141903 11:20:39:844 CC [NW->MS] CC__SETUP
OTA (PCORE) 1125419 738142144 11:20:39:844 CC [MS->NW] CC__CALL_CONFIRMED
OTA (PCORE) 1125725 738153299 11:20:40:550 RRM_TDD [MS->NW] RR__MEASUREMENT_REPORT
OTA (PCORE) 1125765 738156615 11:20:40:786 RRM_TDD [NW->MS] RR__ASSIGNMENT_COMMAND
//到alerting,就是铃声开始响
OTA (PCORE) 1125854 738159798 11:20:40:990 CC [MS->NW] CC__ALERTING
OTA (PCORE) 1126976 738231482 11:20:45:513 RRM_TDD [MS->NW] RR__MEASUREMENT_REPORT
//这里connect接通
OTA (PCORE) 1127489 738270247 11:20:47:977 CC [MS->NW] CC__CONNECT
OTA (PCORE) 1127668 738277273 11:20:48:393 CC [NW->MS] CC__CONNECT_ACKNOWLEDGE
OTA (PCORE) 1137630 738313973 11:20:50:833 RRM_TDD [MS->NW] RR__MEASUREMENT_REPORT
//挂断，释放CC连接
OTA (PCORE) 1139853 738331359 11:20:51:839 CC [NW->MS] CC__DISCONNECT
OTA (PCORE) 1139870 738331362 11:20:51:839 CC [MS->NW] CC__RELEASE
OTA (PCORE) 1140312 738335109 11:20:52:039 CC [NW->MS] CC__RELEASE_COMPLETE
//释放CC连接的承载RR连接
OTA (PCORE) 1140996 738336982 11:20:52:239 RRM_TDD [NW->MS] RR__CHANNEL_RELEASE
如果CC流程完整，但是报告是自动挂断，那么就看网络是否下发了 CC__DISCONNECT 或者RR__CHANNEL_RELEASE，如果有，就说明可能网络或者对端的问题。
如果CC流程不完整，没有下发CC__DISCONNECT 或者RR__CHANNEL_RELEASE，那么就说明是RR连接中断了，需要在通话中断的地方（RR__MEASUREMENT_REPORT不再出现的附近）
来查看RR层哪里出现了问题。
一般以下两种情况比较常见：
//N200 错误
PS 547587 839036 15:32:11:525 LISR2HISR_CTIRQ1 - RRM_2 MSG_ID_LAPDM_RR_REL_IND N200 error
//RLF 错误
PS 850942 752647 15:36:22:230 L1_2 - RRM_2 MSG_ID_LAPDM_RR_ERROR_IND raido link failure
这两种通常都是由信号质量差导致的，信号质量需要查看
547310, 917659, 838713, 15:32:09:725 2017/02/06, MOD_MPAL_2, MOD_RRM_2, RRM_MPAL_SAP, MSG_ID_MPAL_RR_SERV_DEDI_MEAS_IND
Local_Parameter --> Len = 32, Addr = 0xF259BA8C
mpal_rr_serv_dedi_meas_ind_struct = (struct)
ref_count = 0x01
lp_reserved = 0xf2
msg_len = 0x0020
rlac_full_in_quarter_dbm = 0xfe64
rlac_sub_in_quarter_dbm = 0xfe65 //信号强度不应小于-105
rxqual_full_avg = 0x07
rxqual_sub_avg = 0x05 //信号质量不应小于-4
接通和挂断的时间点（）
1、MO未接通自动挂掉
在modem log中看到
[MS->NW] MM__CM_SERVICE_REQUEST
[MS->NW] RR__CHANNEL_REQUEST
[MS->NW] RR__CHANNEL_REQUEST
[NW->MS] RR__SI_2TER (ARFCN[60], TC[5])
[NW->MS] RR__IMMEDIATE_ASSIGNMENT
[NW->MS] RR__SI_6 (ARFCN[60], TC[255])
[MS->NW] RR__CLASSMARK_CHANGE
[NW->MS] MM__ABORT
[MS->NW] RR__MEASUREMENT_REPORT
[NW->MS] RR__CHANNEL_RELEASE
MM_ABORT在协议TS 24.008 4.3.5中
2、接到来电，未接听自动挂断的
从log看测试机和配合机都是收到了网络发来的disconnect命令，挂断case都为为44 requested circuit/channel not available，未网络故障。
测试机：
398601, 0, 330658970, 14:47:47:752 2017/01/09, MOD_CC, , TRACE_PEER, [NW->MS] CC_DISCONNECT
398616, 0, 330658973, 14:47:47:752 2017/01/09, MOD_CC, , TRACE_PEER, [MS->NW] CCRELEASE
398939, 0, 330662434, 14:47:47:960 2017/01/09, MOD_CC, , TRACE_PEER, [NW->MS] CCRELEASE_COMPLETE
配合机：
374430, 0, 329598595, 14:47:48:782 2017/01/09, MOD_CC, , TRACE_PEER, [NW->MS] CCDISCONNECT
374446, 0, 329598598, 14:47:48:782 2017/01/09, MOD_CC, , TRACE_PEER, [MS->NW] CCRELEASE
374770, 0, 329605952, 14:47:49:386 2017/01/09, MODCC, , TRACE_PEER, [NW->MS] CC__RELEASE_COMPLETE
3、关于mtk平台SRVCC的log实例
Hi sir
从log看来，手机带的SRVCC的能力都是正常的，手机SRVCC 都是成功的，但是SRVCC 成功后网络每次都下发了CC disconnect，应该是网络问题，建议和对比机多做下对比测试，谢谢
Type Index Time Local Time Module Message Comment Time Different
SYS 2241900 1942053 16:52:20:105 NIL [AT_I p20, s10]ATD13903022925;
SYS 2765855 1950976 16:53:04:575 NIL [AT_I p20, s10]ATD13903022925;
SYS 3095384 1954764 16:53:23:575 NIL [IMSP_AT_I s21]AT+ESRVCCTFR=1,1,0,0,2,0,2,"13903022925",,
SYS 3095418 1954764 16:53:23:575 NIL [IMSP_AT_R s21]+ESRVCCTFR: 1, 1
SYS 3240633 1972861 16:54:54:155 NIL [AT_I p20, s10]ATD13903022925;
OTA 3491911 1976931 16:55:14:355 ERRC_CONN [NW->MS] ERRC_MobilityFromEUTRACommand(CSFB:[0],purpose:[MobilityFromEUTRACommand_r8_IEs_purpose_handover_selected],targetRAT:[Handover_targetRAT_Type_geran])
OTA 3492866 1976957 16:55:14:580 RRM [NW->MS] RR__PHYSICAL_INFORMATION
OTA 3492870 1976957 16:55:14:580 RRM [MS->NW] RR__HANDOVER_COMPLETE
SYS 3494267 1976983 16:55:14:780 NIL [IMSP_AT_I s21]AT+ESRVCCTFR=1,1,0,0,3,0,2,"13903022925",,
SYS 3494288 1976983 16:55:14:780 NIL [IMSP_AT_R s21]+ESRVCCTFR: 1, 1
OTA 3496629 1977026 16:55:14:980 CC [NW->MS] CC__DISCONNECT
OTA 3496642 1977026 16:55:14:980 CC [MS->NW] CC__RELEASE
OTA 3497024 1977105 16:55:15:380 CC [NW->MS] CC__RELEASE_COMPLETE
SYS 3605943 1979077 16:55:25:200 NIL [AT_I p20, s10]ATD13903022925;
OTA 3609752 1979134 16:55:25:400 ESM [NW->MS] ESM_MSG_ACTIVATE_DEDICATED_EPS_BEARER_CONTEXT_REQUEST (PTI:0, EBI:7)
OTA 3609969 1979134 16:55:25:400 ESM [MS->NW] ESM_MSG_ACTIVATE_DEDICATED_EPS_BEARER_CONTEXT_ACCEPT (PTI:0, EBI:7)
OTA 3627337 1979420 16:55:26:800 ESM [NW->MS] ESM_MSG_MODIFY_EPS_BEARER_CONTEXT_REQUEST (PTI:0, EBI:7)
OTA 3627556 1979420 16:55:26:800 ESM [MS->NW] ESM_MSG_MODIFY_EPS_BEARER_CONTEXT_ACCEPT (PTI:0, EBI:7)
SYS 4177787 1996523 16:56:52:365 NIL [AT_I p20, s10]ATD13903022925;
SIP 139 16:57:10:522 [MS->NW]INVITE sip:[2409:8019:8430:4500:0000:0000:0000:0008]:9900;Hpt=8fa2_16;CxtId=3;TRC=ffffffff-ffffffff SIP/2.0
SIP 140 16:57:10:689 [NW->MS]SIP/2.0 100 Trying
SIP 141 16:57:11:212 [NW->MS]SIP/2.0 200 OK
SIP 142 16:57:11:245 [MS->NW]ACK sip:[2409:8019:8430:4500:0000:0000:0000:0008]:9900;Hpt=8fa2_16;CxtId=3;TRC=ffffffff-ffffffff SIP/2.0
OTA 4547843 2000758 16:57:13:565 ERRC_CONN [NW->MS] ERRC_MobilityFromEUTRACommand(CSFB:[0],purpose:[MobilityFromEUTRACommand_r8_IEs_purpose_handover_selected],targetRAT:[Handover_targetRAT_Type_geran])
SYS 4550218 2000803 16:57:13:765 NIL [IMSP_AT_I s21]AT+ESRVCCTFR=1,1,0,0,3,0,2,"13903022925",,
SYS 4550239 2000803 16:57:13:765 NIL [IMSP_AT_R s21]+ESRVCCTFR: 1, 1
OTA 4552643 2000842 16:57:13:965 RRM [MS->NW] RR__MEASUREMENT_REPORT
OTA 4552688 2000845 16:57:13:965 CC [NW->MS] CC__DISCONNECT
SIP 143 16:57:17:039 [NW->MS]BYE sip:+8613903029925@[2409:8809:84F0:136D:CF50:041A:F6BE:D958]:50001 SIP/2.0
SYS 4742879 2004164 16:57:30:570 NIL [AT_I p20, s10]ATD13903022925;
OTA 5051207 2007543 16:57:47:570 ERRC_CONN [NW->MS] ERRC_MobilityFromEUTRACommand(CSFB:[0],purpose:[MobilityFromEUTRACommand_r8_IEs_purpose_handover_selected],targetRAT:[Handover_targetRAT_Type_geran])
OTA 5052151 2007569 16:57:47:570 RRM [NW->MS] RR__PHYSICAL_INFORMATION
OTA 5052155 2007569 16:57:47:570 RRM [MS->NW] RR__HANDOVER_COMPLETE
SYS 5053538 2007595 16:57:47:775 NIL [IMSP_AT_I s21]AT+ESRVCCTFR=1,1,0,0,3,0,2,"13903022925",,
SYS 5053559 2007595 16:57:47:775 NIL [IMSP_AT_R s21]+ESRVCCTFR: 1, 1
OTA 5056032 2007641 16:57:47:975 CC [NW->MS] CC__DISCONNECT
OTA 5056045 2007641 16:57:47:975 CC [MS->NW] CC__RELEASE
From:
To:
CSeq: 44 INVITE
Allow: INVITE,ACK,CANCEL,BYE,UPDATE,REFER,NOTIFY,MESSAGE,PRACK,OPTIONS
Contact:
Require: precondition,100rel
User-Agent: VoLTE/WFC UA
RSeq: 1
P-Early-Media: gated
Feature-Caps: *;+g.3gpp.srvcc;+g.3gpp.mid-call;+g.3gpp.srvcc-alerting
Recv-Info: g.3gpp.state-and-event-info
Content-Length: 547
Content-Type: application/sdp
v=0
4、可以查看cs的连接状态
自动挂断是由于在手机发出[MS->NW] CC__CONNECT，网络还没有回应CC__CONNECT_ACKNOWLEDGE的情况下发生的，请问此问题的复现概率多大，请在同一地点同样的时刻做对比机测试，同时观察复现率
Type Index Time Local Time Module Message Comment Time Different
OTA (PCORE) 221930 8071266 08:29:37:055 EMM_NASMSG [NW->MS] EMM_CS_Service_Notification(paging identity="TMSI_PAGING_TYPE")
OTA (PCORE) 225351 8082440 08:29:37:626 RRM_TDD [MS->NW] RR__PAGING_RESPONSE
OTA (PCORE) 228739 8118606 08:29:40:125 CC [NW->MS] CC__SETUP
OTA (PCORE) 228933 8118825 08:29:40:125 CC [MS->NW] CC__CALL_CONFIRMED
OTA (PCORE) 229300 8132778 08:29:41:032 CC [MS->NW] CC__ALERTING
OTA (PCORE) 230902 8261717 08:29:49:280 CC [MS->NW] CC__CONNECT
PS (PCORE) 232038 8349260 08:29:54:887 L1HISR - RRM_TDD MSG_ID_LAPDM_RR_ERROR_IND
232038, 0, 8349260, 08:29:54:887 2017/01/22, MOD_L1HISR, MOD_RRM_TDD, L1HISR_GAS_SAP, MSG_ID_LAPDM_RR_ERROR_IND
...
error_cause = ERROR_TIMER_EXPD_N200_ABNORMAL_REL (enum 2)
channel_type = FACCH (enum 25)
...
PS (PCORE) 232243 8350003 08:29:54:887 RATCM [RATCM] cs_conn_state = RATCM_CS_IDLE, ps_conn_state = RATCM_PS_IDLE
5.切换失败造成自动挂断
出现该问题的原因是UE切换失败造成的。
PS 547310 838713 15:32:09:725 MPAL_2 - RRM_2 MSG_ID_MPAL_RR_SERV_DEDI_MEAS_IND rxqual_sub_avg = 0x05
//网络要求UE进行切换
OTA 547379 838752 15:32:09:925 RRM_2 [NW->MS] RR__HANDOVER_COMMAND
PS 547395 838764 15:32:10:125 RRM_2 [RMC] Target_arfcn = 656, F_O = 1169239, E_O = 7924
PS 547449 838841 15:32:10:525 MPAL_2 - RRM_2 MSG_ID_MPAL_RR_HANDOVER_FAIL_IND
PS 547460 838841 15:32:10:525 RRM_2 - LAPDM_2 MSG_ID_RR_LAPDM_RECON_REQ
//切换失败，原因是T3124计时器超时，说明是网络没有回应造成的切换失败。
OTA 547461 838841 15:32:10:525 RRM_2 [MS->NW] RR__HANDOVER_FAILURE Abnormal release, timer expired (3)
//重新连接old channel，但old channel也没有回应，于是出现了N200 error，RR连接断开。
PS 547557 838998 15:32:11:325 MPAL_2 - RRM_2 MSG_ID_MPAL_RR_SERV_DEDI_MEAS_IND rxqual_sub_avg = 0x07
PS 547587 839036 15:32:11:525 LISR2HISR_CTIRQ1 - RRM_2 MSG_ID_LAPDM_RR_REL_IND N200 error
6、RLF发生后MS端发起重连的实例
第二组：
//同样是信号质量差，但第二组是由于RLF造成的通话中断。根据协议，RLF发生后会尝试进行call reestablishment，故耗费了几秒钟去找合适的小区重建call。
此题中未找到合适的小区，故上报ecpi 较晚。
Type Index Time Local Time Module Message Comment Time Different
OTA 853907 376621 14:15:01:760 RRM [MS->NW] RR__MEASUREMENT_REPORT
//信号质量差导致Radio Link Failure错误
PS 853957 376629 14:15:01:760 LISR2HISR_CTIRQ1 - RRM MSG_ID_LAPDM_RR_ERROR_IND
//channel断开
PS 853973 376629 14:15:01:760 RRM - MPAL MSG_ID_RR_MPAL_DEDICATED_CHANNEL_DISCONNECT_REQ
PS 854034 376638 14:15:01:760 MPAL - RRM MSG_ID_MPAL_RR_DEDICATED_CHANNEL_DISCONNECT_CNF
PS 854042 376638 14:15:01:760 RRM - RATCM MSG_ID_RATCM_GAS_CONN_LOSS_IND
PS 854079 376638 14:15:01:760 RRM [RMC] Radio Link Trigger reselection!
PS 854161 376638 14:15:01:760 RATCM - MM MSG_ID_MM_RATCM_CONN_LOSS_IND
PS 854163 376638 14:15:01:760 MM CM rej because RADIO LINK FAILURE
//尝试重建call
PS 854165 376638 14:15:01:760 MM MM new State: MM_WAIT_FOR_REESTABLISH
PS 854180 376639 14:15:01:760 CC ENTER RE-ESTABLISHMENT MODE
OTA 854635 376696 14:15:01:960 RRM [NW->MS] RR__SI_2 (ARFCN[123], TC[1])
OTA 855148 376782 14:15:02:560 RRM [NW->MS] RR__SI_2 (ARFCN[648], TC[1])
OTA 855763 376884 14:15:02:960 RRM [NW->MS] RR__SI_2TER (ARFCN[120], TC[5])
OTA 856755 377047 14:15:03:760 RRM [NW->MS] RR__SI_4 (ARFCN[118], TC[7])
OTA 857287 377141 14:15:04:360 RRM [NW->MS] RR__SI_2 (ARFCN[118], TC[1])
PS 860562 377377 14:15:05:560 RRM [RMC] RMC do reselection, num_of_top_six[6]!
//没有合适小区进行重建call，放弃重建，报告通话中断。
PS 860588 377377 14:15:05:560 MM MM new State: MM_IDLE_NO_CELL_AVAILABLE
PS 860603 377377 14:15:05:560 CC - CSM MSG_ID_MNCC_REL_CNF
PS 860655 377377 14:15:05:560 L4C - CSM MSG_ID_L4CCSM_CC_ABORT_CALL_REQ
//ECPI上报通话中断
SYS 860714 377377 14:15:05:560 NIL [IMSP_U]+ECPI: 1,133,,,,,"",,"",2165
OTA 861247 377422 14:15:05:760 RRM [NW->MS] RR__SI_4 (ARFCN[115], TC[7])
OTA 861293 377516 14:15:06:245 RRM [NW->MS] RR__SI_2 (ARFCN[115], TC[1])
OTA 861570 377659 14:15:06:955 MM [MS->NW] MM__LOCATION_UPDATING_REQUEST (LU type: MM_NORMAL_LU)
7、涉及call状态机，AP和Modem的同步（协议24.008）
发出connect或收到connect消息，mt或mo进入active状态
发出disconnect要等收到网络的cc_release才进入idle状态
主叫的响铃与被叫是否建立起连接无关，比如被叫没信号的时候，主叫听到"您拨打的号码无法接通"，主叫就是在响铃状态。
被叫能否建立起连接只会影响主叫能不能进入cc_connect状态。即最终接通电话的状态。
8、关于paging类型（确认协议）
Spec25.331中有详细定义，RRC_PAGING_TYPE1/RRC_PAGING_TYPE2都可以用来传输paging，网络会根据当前UE 的状态选择使用：
8.1.2.1章节中：
RRC_PAGING_TYPE1 is used to transmit paging information to selected UEs in idle mode, CELL_PCH or URA_PCH state
using the paging control channel (PCCH).
8.1.11.1章节中：
RRC_PAGING_TYPE2 is used to transmit dedicated paging information to one UE in connected mode in CELL_DCH ,
CELL_FACH or CELL_PCH (FDD and 1.28 Mcps TDD only) state.
即：
RRC_PAGING_TYPE1用于idle态，CELL_PCH or URA_PCH 态，PCCH
RRC_PAGING_TYPE2用于CELL_DCH, CELL_FACH or CELL_PCH，DCCH
PAGING有很多的类型，分为CS域和PS域两大类，CS域包括被叫通话，短信，彩信等，PS域主要就是数据业务相关的：
OTA 1546750 487939 14:53:13:455 ERRC_CEL [NW->MS] PAGING, PagingRecordList[KAL_TRUE], SIB Modification[KAL_FALSE], ETWS[KAL_FALSE], CMAS[KAL_FALSE]
这次收到的CS域的通话被叫：
PS 1546760 487939 14:53:13:455 ERRC_CEL [PAGING] Rx Paging for UE with S-TMSI: mmec[10100100b], m-tmsi:[11101100b 10001100b 00111101b 00000101b]
PS 1546761 487939 14:53:13:455 ERRC_CEL [PAGING] ueid matched?[KAL_TRUE]: sim_status[ENASAS_SIM_VALID], ueid sel[PagingUE_Identity_s_TMSI_selected], stmsi_valid in SIM[KAL_TRUE]
PS 1546762 487939 14:53:13:455 ERRC_CEL [CEL_DI/LV] send PAGING_IND to EMM on [ENASAS_CN_DO