一、UE attach 流程
UE要获得服务，需要在网上注册，这个注册过程叫做Attach。Attach默认建立了过程EPS承载(承载可以简单地认为是核心网络UE通路之间)。从而使UE/User保持一直在线IP连接，并且PGW默认情况下，将预告定义为相应的EPS承载的策略与计费规则。用户完成网络接入流程后，开始向网络注册。
attch 信令流程：
attach log：
二、IMS注册流程
IMS注册流程log：
信令详解
1. UE首先，发起注册请求，没有任何安全机制保护，但它包含了一些注册请求IMS所需的安全参数。 0x156E IMS SIP Message -- IMS_SIP_REGISTER/INFORMAL_RESPONSE Version = 1 Direction = UE_TO_NETWORK SDP Presence = 0 SIP Call ID Length = 59 SIP Message Length = 1570 SIP Message Logged Bytes = 1571 Message ID = IMS_SIP_REGISTER Response Code = INFORMAL_RESPONSE (0) CM Call ID = 255 //会话标志在整个注册过程中保持不变。有本地标志@主机组成，其中@主机为UAC的IP地址。 SIP Call ID =[emailprotected]:8804:8000:186e:9fb:f711:a6d6:ead Sip Message = REGISTER sip:ims.mnc000.mcc460.3gppnetwork.org SIP/2.0 f: ;tag=842020773 t: CSeq: 842020765 REGISTER i:[emailprotected]:8804:8000:186e:9fb:f711:a6d6:ead v: SIP/2.0/TCP [2409:8804:8000:186e:9fb:f711:a6d6:ead]:5060;branch=z9hG4bK3403392309 Max-Forwards: 70 m: ; g.3gpp.accesstype="cellular2"; g.3gpp.icsi-ref="urn:urn-7:3gpp-service.ims.icsi.mmtel"; g.3gpp.smsip;video Authorization: Digest uri="sip:ims.mnc000.mcc460.3gppnetwork.org",username="[emailprotected]",response="",realm="ims.mnc000.mcc460.3gppnetwork.org",nonce="" //注册周期。如果是0，则为注册 Expires: 600000 Require: sec-agree Proxy-Require: sec-agree k: path,sec-agree Allow: INVITE,BYE,CANCEL,ACK,NOTIFY,UPDATE,PRACK,INFO,MESSAGE,OPTIONS Security-Client: ipsec-3gpp; alg=hmac-md5-96; ealg=des-ede3-cbc; spi-c=2400192191; spi-s=4029922906; port-c=8001; port-s=8901,ipsec-3gpp; alg=hmac-md5-96; ealg=aes-cbc; spi-c=2400192191; spi-s=4029922906; port-c=8001; port-s=8901,ipsec-3gpp; alg=hmac-md5-96; ealg=null; spi-c=2400192191; spi-s=4029922906; port-c=8001; port-s=8901,ipsec-3gpp; alg=hmac-sha-1-96; ealg=des-ede3-cbc; spi-c=2400192191; spi-s=4029922906; port-c=8001; port-s=8901,ipsec-3gpp; alg=hmac-sha-1-96; ealg=aes-cbc; spi-c=2400192191; spi-s=4029922906; port-c=8001; port-s=8901,ipsec-3gpp; alg=hmac-sha-1-96; ealg=null; spi-c=2400192191; spi-s=4029922906; port-c=8001; port-s=8901 l: 0
2. Server收到请求后，解码消息，添加自己的安全参数和权利鉴定方法，并发送一份信息unauthorized的响应去challenge UE。 0x156E IMS SIP Message -- IMS_SIP_REGISTER/UNAUTHORIZED Version = 1 Direction = NETWORK_TO_UE SDP Presence = 0 SIP Call ID Length = 59 SIP Message Length = 656 SIP Message Logged Bytes = 657 Message ID = IMS_SIP_REGISTER Response Code = UNAUTHORIZED (401) CM Call ID = 255 SIP Call ID =[emailprotected]:8804:8000:186e:9fb:f711:a6d6:ead Sip Message = SIP/2.0 401 Unauthorized Via: SIP/2.0/TCP [2409:8804:8000:186E:09FB:F711:A6D6:0EAD]:5060;branch=z9hG4bK3403392309 Call-ID:[emailprotected]:8804:8000:186e:9fb:f711:a6d6:ead From: ;tag=842020773 To: ;tag=o8bvb89i CSeq: 842020765 REGISTER WWW-Authenticate: Digest realm="ims.mnc000.mcc460.3gppnetwork.org",nonce="C7wh VcFEIgJOIlDgpDBXQfzQf5nj3CVCjBnxfy 9wk=",algorithm=AKAv1-MD5 Security-Server: ipsec-3gpp;alg=hmac-md5-96;prot=esp;mod=trans;ealg=null;spi-c=3150465912;spi-s=3930932050;port-c=9950;port-s=9900 Content-Length: 0
3. UE收到401条消息后，将解码消息，然后计算并重新发送注册请求。 0x156E IMS SIP Message -- IMS_SIP_REGISTER/INFORMAL_RESPONSE Version = 1 Direction = UE_TO_NETWORK SDP Presence = 0 SIP Call ID Length = 59 SIP Message Length = 1876 SIP Message Logged Bytes = 1877 Message ID = IMS_SIP_REGISTER Response Code = INFORMAL_RESPONSE (0) CM Call ID = 255 SIP Call ID =[emailprotected]:8804:8000:186e:9fb:f711:a6d6:ead Sip Message = REGISTER sip:ims.mnc000.mcc460.3gppnetwork.org SIP/2.0 f: ;tag=842022485 t: CSeq: 842020766 REGISTER i:[emailprotected]:8804:8000:186e:9fb:f711:a6d6:ead v: SIP/2.0/TCP [2409:8804:8000:186e:9fb:f711:a6d6:ead]:8901;branch=z9hG4bK1614040778 Max-Forwards: 70 m: ; g.3gpp.icsi-ref="urn:urn-7:3gpp-service.ims.icsi.mmtel"; g.3gpp.smsip;video; g.3gpp.accesstype="cellular2" P-Access-Network-Info: 3GPP-E-UTRAN-TDD; utran-cell-id-3gpp=4600018BE192D322 Security-Verify: ipsec-3gpp;alg=hmac-md5-96;prot=esp;mod=trans;ealg=null;spi-c=3150465912;spi-s=3930932050;port-c=9950;port-s=9900 l: 0 Authorization: Digest username="[emailprotected]",realm="ims.mnc000.mcc460.3gppnetwork.org",uri="sip:ims.mnc000.mcc460.3gppnetwork.org",nonce="C7wh VcFEIgJOIlDgpDBXQfzQf5nj3CVCjBnxfy 9wk=",algorithm=AKAv1-MD5,reponse="9fba77a4341e4c1a160cf7b8991aa8cf" Expires: 600000 Require: sec-agree Proxy-Require: sec-agree k: path,sec-agree Allow: INVITE,BYE,CANCEL,ACK,NOTIFY,UPDATE,PRACK,INFO,MESSAGE,OPTIONS Security-Client: ipsec-3gpp; alg=hmac-md5-96; ealg=des-ede3-cbc; spi-c=2400192191; spi-s=4029922906; port-c=8001; port-s=8901,ipsec-3gpp; alg=hmac-md5-96; ealg=aes-cbc; spi-c=2400192191; spi-s=4029922906; port-c=8001; port-s=8901,ipsec-3gpp; alg=hmac-md5-96; ealg=null; spi-c=2400192191; spi-s=4029922906; port-c=8001; port-s=8901,ipsec-3gpp; alg=hmac-sha-1-96; ealg=des-ede3-cbc; spi-c=2400192191; spi-s=4029922906; port-c=8001; port-s=8901,ipsec-3gpp; alg=hmac-sha-1-96; ealg=aes-cbc; spi-c=2400192191; spi-s=4029922906; port-c=8001; port-s=8901,ipsec-3gpp; alg=hmac-sha-1-96; ealg=null; spi-c=2400192191; spi-s=4029922906; port-c=8001; port-s=8901
4. 最后，网络将UE第二次发送来的请求进行解码处理，然后和本地对比，如果匹配，则会发送200 OK出去。其中200 Ok消息包含了一系列用户注册的身份标识。 0x156E IMS SIP Message -- IMS_SIP_REGISTER/OK Version = 1 Direction = NETWORK_TO_UE SDP Presence = 0 SIP Call ID Length = 59 SIP Message Length = 771 SIP Message Logged Bytes = 772 Message ID = IMS_SIP_REGISTER Response Code = OK (200) CM Call ID = 255 SIP Call ID = [email protected]:8804:8000:186e:9fb:f711:a6d6:ead Sip Message = SIP/2.0 200 OK Via: SIP/2.0/TCP [2409:8804:8000:186E:09FB:F711:A6D6:0EAD]:8901;branch=z9hG4bK1614040778 Call-ID: [email protected]:8804:8000:186e:9fb:f711:a6d6:ead From: ;tag=842022485 To: ;tag=kn9vambk CSeq: 842020766 REGISTER Accept-Resource-Priority: wps.4 P-Associated-URI: , Contact: ;expires=3600;+g.3gpp.icsi-ref="urn:urn-7:3gpp-service.ims.icsi.mmtel";+g.3gpp.smsip;video;+g.3gpp.accesstype="cellular2" Path: 2409:8014:8201:0010:0000:0000:0000:0009] PCSCF的IP地址:9900;lr> Content-Length: 0
5. 可是，这里有一个问题，在UE发起register之前，它是如何得知SIP server的地址的。 首先，UE会在PDN connect request 中请求PCSCF的地址，然后通过PCSCF来和server进行交互的。 LTE NAS ESM Plain OTA Outgoing Message -- PDN connectivity request Msg pkt_version = 1 (0x1) rel_number = 9 (0x9) rel_version_major = 5 (0x5) rel_version_minor = 0 (0x0) eps_bearer_id_or_skip_id = 0 (0x0) prot_disc = 2 (0x2) (EPS session management messages) trans_id = 2 (0x2) msg_type = 208 (0xd0) (PDN connectivity request) lte_esm_msg pdn_connectivity_req pdn_type = 3 (0x3) (Ipv4v6) req_type = 1 (0x1) (initial request) info_trans_flag_incl = 0 (0x0) access_pt_name_incl = 1 (0x1) access_pt_name_ num_acc_pt_val = 4 (0x4) acc_pt_name_val[0] = 3 (0x3) (length) acc_pt_name_val[1] = 73 (0x49) (I) acc_pt_name_val[2] = 77 (0x4d) (M) acc_pt_name_val[3] = 83 (0x53) (S) ... sm_container[2] container_id = 1 (0x1) (P-CSCF IPv6 Address Request) container_len = 0 (0x0) sm_container[3] container_id = 12 (0xc) (P-CSCF IPv4 Address Request) container_len = 0 (0x0)
6. 然后，网络会提供PCSCF的地址给UE在activate default EPS bear request中。 LTE NAS ESM Plain OTA Incoming Message -- Activate default EPS bearer context request Msg pkt_version = 1 (0x1) rel_number = 9 (0x9) rel_version_major = 5 (0x5) rel_version_minor = 0 (0x0) eps_bearer_id_or_skip_id = 6 (0x6) prot_disc = 2 (0x2) (EPS session management messages) trans_id = 2 (0x2) msg_type = 193 (0xc1) (Activate default EPS bearer context request) lte_esm_msg act_def_eps_bearer_context_req eps_qos qci = 5 (0x5) (QC5) ... access_point num_acc_pt_val = 23 (0x17) acc_pt_name_val[0] = 3 (0x3) (length) acc_pt_name_val[1] = 105 (0x69) (i) acc_pt_name_val[2] = 109 (0x6d) (m) acc_pt_name_val[3] = 115 (0x73) (s) ... sm_container[1] container_id = 1 (0x1) (P-CSCF IPV6 Address) container_len = 16 (0x10) address = 0x24098014820100100000000000000009 (2409:8014:8201:10:0:0:0:9) sm_container[2] container_id = 1 (0x1) (P-CSCF IPV6 Address) container_len = 16 (0x10) address = 0x24098014860100100000000000000009 (2409:8014:8601:10:0:0:0:9) connectivity_type_incl = 0 (0x0)
7. 在注册成功后，UE通过订阅的方式从网络得到自己的状态。 IMS SIP Message -- IMS_SIP_SUBSCRIBE/INFORMAL_RESPONSE Version = 1 Direction = UE_TO_NETWORK SDP Presence = 0 SIP Call ID Length = 59 SIP Message Length = 893 SIP Message Logged Bytes = 894 Message ID = IMS_SIP_SUBSCRIBE Response Code = INFORMAL_RESPONSE (0) CM Call ID = 255 SIP Call ID = [email protected]:8804:8000:186e:9fb:f711:a6d6:ead Sip Message = SUBSCRIBE sip:[email protected] SIP/2.0 f: ;tag=842022751 t: CSeq: 842022747 SUBSCRIBE i: [email protected]:8804:8000:186e:9fb:f711:a6d6:ead v: SIP/2.0/UDP [2409:8804:8000:186e:9fb:f711:a6d6:ead]:8901;branch=z9hG4bK2298242861 Max-Forwards: 70 Route: P-Access-Network-Info: 3GPP-E-UTRAN-TDD; utran-cell-id-3gpp=4600018BE192D322 Security-Verify: ipsec-3gpp;alg=hmac-md5-96;prot=esp;mod=trans;ealg=null;spi-c=3150465912;spi-s=3930932050;port-c=9950;port-s=9900 //UE是在查询注册的状态可以从"reg"关键字知道 o: reg l: 0 Require: sec-agree Proxy-Require: sec-agree m: //订阅周期 Expires: 600000 P-Preferred-Identity:
8. 网络收到订阅请求后通过200 Ok表示收到请求。 0x156E IMS SIP Message -- IMS_SIP_SUBSCRIBE/OK Version = 1 Direction = NETWORK_TO_UE SDP Presence = 0 SIP Call ID Length = 59 SIP Message Length = 816 SIP Message Logged Bytes = 817 Message ID = IMS_SIP_SUBSCRIBE Response Code = OK (200) CM Call ID = 255 SIP Call ID = [email protected]:8804:8000:186e:9fb:f711:a6d6:ead Sip Message = SIP/2.0 200 OK
9. 接着网络向UE发送通知消息告诉UE的状态 0x156E IMS SIP Message -- IMS_SIP_NOTIFY/INFORMAL_RESPONSE Version = 1 Direction = NETWORK_TO_UE SDP Presence = 0 SIP Call ID Length = 59 SIP Message Length = 1737 SIP Message Logged Bytes = 1738 Message ID = IMS_SIP_NOTIFY Response Code = INFORMAL_RESPONSE (0) CM Call ID = 255 SIP Call ID = [email protected]:8804:8000:186e:9fb:f711:a6d6:ead Sip Message = NOTIFY ... Max-Forwards: 69 Event: reg //订阅状态为active表明订阅已被接受且授权成功。时间周期为600000 Subscription-State: active;expires=600000 P-Asserted-Identity: Content-Length: 666 Content-Type: application/reginfo+xml sip:[email protected][2409:8804:8000:186E:09FB:F711:A6D6:0EAD]:8901;Hpt=8e82_16;srti=d0_1025 sip:[email protected][2409:8804:8000:186E:09FB:F711:A6D6:0EAD]:8901;Hpt=8e82_16;srti=d0_1025
10. 最后，UE回复200 Ok确认已经收到回复 2019 Jul 19 03:42:29.233 [FB] 0x156E IMS SIP Message -- IMS_SIP_NOTIFY/OK Subscription ID = 1 Version = 1 Direction = UE_TO_NETWORK SDP Presence = 0 SIP Call ID Length = 61 SIP Message Length = 695 SIP Message Logged Bytes = 696 Message ID = IMS_SIP_NOTIFY Response Code = OK (200) CM Call ID = 255 SIP Call ID = [email protected]:8805:445:24c3:17d1:369d:93a1:9217 Sip Message = SIP/2.0 200 OK Via: SIP/2.0/UDP [2409:8095:0500:0000:0000:0000:0000:012F]:9900;branch=z9hG4bK5n9ncrlm5dlj3n4jj99cdb4gj;Role=3;Hpt=8e62_36;X-HwDim=3 Record-Route: <sip:[2409:8095:0500:0000:0000:0000:0000:012F]:9900;lr;Hpt=8e62_16;CxtId=3;TRC=ffffffff-ffffffff> Call-ID: [email protected]:8805:445:24c3:17d1:369d:93a1:9217 From: <sip:[email protected]>;tag=ztesipUt0kdP15AOTda*9-12-16648*hbfh.9 To: +8615827428390 <sip:[email protected]>;tag=2002433287 CSeq: 1001 NOTIFY Content-Length: 0 P-Access-Network-Info: 3GPP-E-UTRAN-TDD; utran-cell-id-3gpp=4600051D0DC5900B User-Agent: KEPLER_SS8825_PKQ1.190223.001