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+## 1、注册
+- 注册请求：
+```http
+REGISTER sip:130909115229300920@10.64.49.44:7100 SIP/2.0
+Via: SIP/2.0/UDP 10.64.49.218:7100;rport;branch=z9hG4bK4162288924
+From: <sip:130909113319427420@10.64.49.218:7100>;tag=382068091
+To: <sip:130909113319427420@10.64.49.218:7100>
+Call-ID: 143225205
+CSeq: 1 REGISTER
+Contact: <sip:130909113319427420@10.64.49.218:7100>
+Max-Forwards: 70
+User-Agent: Hikvision
+Expires: 7200
+Content-Length: 0
+```
+
+- 回复401：
+```http
+SIP/2.0 401 Unauthorized
+Via: SIP/2.0/UDP 10.64.49.218:7100;rport=7100;branch=z9hG4bK4162288924
+From: <sip:130909113319427420@10.64.49.218:7100>;tag=382068091
+To: <sip:130909113319427420@10.64.49.218:7100>;tag=916944766
+Call-ID: 143225205
+CSeq: 1 REGISTER
+WWW-Authenticate: Digest realm="hik", nonce="a8afe6fcbee6331d89d3eb0d3d19ce39", opaque="a853e4f25298413f9bf3a9aa6767857d", algorithm=MD5
+User-Agent: Hikvision
+Expires: 7200
+Content-Length: 0
+```
+
+- 再次注册：
+```http
+REGISTER sip:130909115229300920@10.64.49.44:7100 SIP/2.0
+Via: SIP/2.0/UDP 10.64.49.218:7100;rport;branch=z9hG4bK3997518011
+From: <sip:130909113319427420@10.64.49.218:7100>;tag=382068091
+To: <sip:130909113319427420@10.64.49.218:7100>
+Call-ID: 143225205
+CSeq: 2 REGISTER
+Contact: <sip:130909113319427420@10.64.49.218:7100>
+Authorization: Digest username="admin", realm="hik", nonce="a8afe6fcbee6331d89d3eb0d3d19ce39", uri="sip:130909115229300920@10.64.49.44:7100", response="907ddb1bcc25174d7de4a96c947fb066", algorithm=MD5, opaque="a853e4f25298413f9bf3a9aa6767857d"
+Max-Forwards: 70
+User-Agent: Hikvision
+Expires: 7200
+Content-Length: 0
+```
+- 注册成功：
+```http
+SIP/2.0 200 OK
+Via: SIP/2.0/UDP 10.64.49.218:7100;rport=7100;branch=z9hG4bK3997518011
+From: <sip:130909113319427420@10.64.49.218:7100>;tag=382068091
+To: <sip:130909113319427420@10.64.49.218:7100>;tag=705514612
+Call-ID: 143225205
+CSeq: 2 REGISTER
+Contact: <sip:130909113319427420@10.64.49.218:7100>
+User-Agent: Hikvision
+Date: 2013-09-10T16:01:51
+Content-Length: 0
+```
+
+
+## 2、注销
+- 注销请求：
+```http
+REGISTER sip:130909115229300920@10.64.49.44:7100 SIP/2.0
+Via: SIP/2.0/UDP 10.64.49.218:7100;rport;branch=z9hG4bK1670314216
+From: <sip:130909113319427420@10.64.49.218:7100>;tag=1928169842
+To: <sip:130909113319427420@10.64.49.218:7100>
+Call-ID: 3187228566
+CSeq: 1 REGISTER
+Contact: <sip:130909113319427420@10.64.49.218:7100>
+Max-Forwards: 70
+User-Agent: Hikvision
+Expires: 0
+Content-Length: 0
+```
+
+- 回复401：
+```http
+SIP/2.0 401 Unauthorized
+Via: SIP/2.0/UDP 10.64.49.218:7100;rport=7100;branch=z9hG4bK1670314216
+From: <sip:130909113319427420@10.64.49.218:7100>;tag=1928169842
+To: <sip:130909113319427420@10.64.49.218:7100>;tag=1002632848
+Call-ID: 3187228566
+CSeq: 1 REGISTER
+WWW-Authenticate: Digest realm="hik", nonce="42dc1acbe02b15743942c0af9314768b", opaque="8e3da4136ac9ab537de09a9932c2a9a3", algorithm=MD5
+User-Agent: Hikvision
+Expires: 0
+Content-Length: 0
+```
+
+- 再次注销:
+```http
+REGISTER sip:130909115229300920@10.64.49.44:7100 SIP/2.0
+Via: SIP/2.0/UDP 10.64.49.218:7100;rport;branch=z9hG4bK317693249
+From: <sip:130909113319427420@10.64.49.218:7100>;tag=1928169842
+To: <sip:130909113319427420@10.64.49.218:7100>
+Call-ID: 3187228566
+CSeq: 2 REGISTER
+Contact: <sip:130909113319427420@10.64.49.218:7100>
+Authorization: Digest username="admin", realm="hik", nonce="42dc1acbe02b15743942c0af9314768b", uri="sip:130909115229300920@10.64.49.44:7100", response="7328353ed26e3f2edf3ff57e834d5665", algorithm=MD5, opaque="8e3da4136ac9ab537de09a9932c2a9a3"
+Max-Forwards: 70
+User-Agent: Hikvision
+Expires: 0
+Content-Length: 0
+```
+
+- 注销成功：
+```http
+SIP/2.0 200 OK
+Via: SIP/2.0/UDP 10.64.49.218:7100;rport=7100;branch=z9hG4bK317693249
+From: <sip:130909113319427420@10.64.49.218:7100>;tag=1928169842
+To: <sip:130909113319427420@10.64.49.218:7100>;tag=409851991
+Call-ID: 3187228566
+CSeq: 2 REGISTER
+Contact: <sip:130909113319427420@10.64.49.218:7100>
+User-Agent: Hikvision
+Date: 2013-09-10T14:04:41
+Content-Length: 0
+```
+
+
+## 3、心跳
+- 请求：
+```http
+MESSAGE sip:130909115229300920@10.64.49.44:7100 SIP/2.0
+Via: SIP/2.0/UDP 10.64.49.218:7100;rport;branch=z9hG4bK2672759896
+From: <sip:130909113319427420@10.64.49.218:7100>;tag=308835751
+To: <sip:130909115229300920@10.64.49.44:7100>
+Call-ID: 63810466
+CSeq: 20 MESSAGE
+Content-Type: Application/MANSCDP+xml
+Max-Forwards: 70
+User-Agent: Hikvision
+Content-Length:   150
+
+<?xml version="1.0"?>
+<Notify>
+<CmdType>Keepalive</CmdType>
+<SN>2749</SN>
+<DeviceID>130909113319427420</DeviceID>
+<Status>OK</Status>
+</Notify>
+```
+
+- 回复：
+```http
+SIP/2.0 200 OK
+Via: SIP/2.0/UDP 10.64.49.218:7100;rport=7100;branch=z9hG4bK2672759896
+From: <sip:130909113319427420@10.64.49.218:7100>;tag=308835751
+To: <sip:130909115229300920@10.64.49.44:7100>;tag=1578583786
+Call-ID: 63810466
+CSeq: 20 MESSAGE
+User-Agent: Hikvision
+Content-Length: 0
+```
+
+
+## 4、目录检索
+- 请求：
+```http
+MESSAGE sip:130909113319427420@10.64.49.218:7100 SIP/2.0
+Via: SIP/2.0/UDP 10.64.49.44:7100;rport;branch=z9hG4bK32925498
+From: <sip:130909115229300920@10.64.49.44:7100>;tag=1307626839
+To: <sip:130909113319427420@10.64.49.218:7100>
+Call-ID: 2367611040
+CSeq: 20 MESSAGE
+Content-Type: Application/MANSCDP+xml
+Max-Forwards: 70
+User-Agent: Hikvision
+Content-Length:   124
+
+<?xml version="1.0"?>
+<Query>
+<CmdType>Catalog</CmdType>
+<SN>471</SN>
+<DeviceID>130909113319427420</DeviceID>
+</Query>
+```
+- 回复：
+```http
+SIP/2.0 200 OK
+Via: SIP/2.0/UDP 10.64.49.44:7100;rport=7100;branch=z9hG4bK32925498
+From: <sip:130909115229300920@10.64.49.44:7100>;tag=1307626839
+To: <sip:130909113319427420@10.64.49.218:7100>;tag=1981225076
+Call-ID: 2367611040
+CSeq: 20 MESSAGE
+User-Agent: Hikvision
+Content-Length: 0
+```