1. ARP请求
- ARP广播自己的地址
- 网关响应
2. 查询DNS 更新时间
- 第一次查询 time.windows.com
- 第二次查询 www.hik-onlink.com
3. IGMP 加入组播
- 组播地址：239.255.255.250
4. SSDP 广播自己的服务 Request Method: NOTIFY
- LOCATION: http://192.168.13.15:49152/upnpdevicedesc.xml\r\n
5. NVR tcp 尝试连接
由上图可以看出，当摄像头（192.168.13.15）发出SSDP NOTIFY后，NVR（192.168.13.101）发送TCP数据包尝试建立三次握手。
6. IPCamera ARP 广播请求 NVR
仅接着摄像头发送ARP广播，请求NVR（192.168.13.101）的MAC地址。
7. NVR arp 响应
之后NVR（192.168.13.101）发送ARP单播相应。
8. NVR 三次握手后 建立HTTP 请求
- TCP 三次握手
- 发起UPNP请求 GET /upnpdevicedesc.xml HTTP/1.1\r\n
9. 摄像头响应 http/xml UPNP
UPNP服务响应采用HTTP/XML的形式描述设备的相信信息。
10. RTSP协议通信
OPTIONS rtsp://192.168.13.15/ch1/main/av_stream RTSP/1.0 CSeq: 1 User-Agent: HIKVISION player NVR V3.4.82 RTSP/1.0 200 OK CSeq: 1 Public: OPTIONS, DESCRIBE, PLAY, PAUSE, SETUP, TEARDOWN, SET_PARAMETER, GET_PARAMETER Date: Fri, Aug 25 2017 14:00:05 GMT DESCRIBE rtsp://192.168.13.15/ch1/main/av_stream RTSP/1.0 CSeq: 2 Accept: application/sdp User-Agent: HIKVISION player NVR V3.4.82 RTSP/1.0 401 Unauthorized CSeq: 2 WWW-Authenticate: Digest realm="4419b65e39d0", nonce="b67c83f03b76a7aea24d021ae1c00e30", stale="FALSE" WWW-Authenticate: Basic realm="4419b65e39d0" Date: Fri, Aug 25 2017 14:00:05 GMT DESCRIBE rtsp://192.168.13.15/ch1/main/av_stream RTSP/1.0 CSeq: 3 Accept: application/sdp Authorization: Basic YWRtaW46QWRtaW41MjI1MjI= User-Agent: HIKVISION player NVR V3.4.82 RTSP/1.0 200 OK CSeq: 3 Content-Type: application/sdp Content-Length: 487 v=0 o=- 1503669605046795 1503669605046795 IN IP4 192.168.13.15 s=Media Presentation e=NONE b=AS:5050 t=0 0 a=control:* m=video 0 RTP/AVP 96 c=IN IP4 192.168.13.15 b=AS:5000 a=recvonly a=control:trackID=1 a=rtpmap:96 H264/90000 a=fmtp:96 profile-level-id=420029; packetization-mode=1; sprop-parameter-sets=Z00AH5pmAoAt/zUBAQFAAAD6AAAw1AE=,aO48gA== a=Media_header:MEDIAINFO=494D4B48010100000400010000000000000000000000000000000000000000000000000000000000; a=appversion:1.0 SETUP rtsp://192.168.13.15/ch1/main/av_stream/trackID=1 RTSP/1.0 CSeq: 4 Transport: RTP/AVP/TCP;unicast;interleaved0-1 Authorization: Basic YWRtaW46QWRtaW41MjI1MjI= User-Agent: HIKVISION player NVR V3.4.82 RTSP/1.0 200 OK CSeq: 4 Session: 1470203379;timeout=60 Transport: RTP/AVP/TCP;unicast;interleaved=0-1;ssrc=404fa5f3;mode="play" Date: Fri, Aug 25 2017 14:00:05 GMT PLAY rtsp://192.168.13.15/ch1/main/av_stream RTSP/1.0 CSeq: 5 Range: npt=0.000- Session: 1470203379 Authorization: Basic YWRtaW46QWRtaW41MjI1MjI=' User-Agent: HIKVISION player NVR V3.4.82 RTSP/1.0 200 OK CSeq: 5 Session: 1470203379 RTP-Info: url=trackID=1;seq=17769 Date: Fri, Aug 25 2017 14:00:05 GMT ....................................................
