GB28181学习（十五）——流传输方式
前言
基于GB/T28181-2022版本，实时流的传输方式包括3种：
- UDP
- TCP被动
- TCP主动
UDP
流程
注意：
- m字段指定传输方式为RTP/AVP；
抓包
- SIP服务器发送INVITE请求；
INVITE sip:[email protected]:5060 SIP/2.0
Via: SIP/2.0/UDP 192.168.0.107:5060;rport;branch=xxx
Max-Forwards: 70
From: sip:[email protected]:5060;tag=xxx
To: sip:[email protected]:5060
Contact: <sip:[email protected]:5060>
Call-ID: xxx
CSeq: 18467 INVITE
Allow: INVITE, ACK, BYE, CANCEL, UPDATE, PRACK
Supported: 100rel
Subject: xxx:xx,xxx:xx
Content-Type: application/sdp
Content-Length: 211
v=0
o=xxx 0 0 IN IP4 192.168.0.107
s=Play
c=IN IP4 192.168.0.107
t=0 0
m=video 36000 RTP/AVP 96 98 97 # 36000为SIP服务数据接收端口
a=recvonly
a=rtpmap:96 PS/90000
a=rtpmap:98 H264/90000
a=rtpmap:97 MPEG4/90000
y=0100000001
- 设备返回200 OK；
SIP/2.0 200 OK
Call-ID: xxx
Contact: <sip:[email protected]:5060>
Content-Length: 226
Content-Type: application/sdp
CSeq: 18467 INVITE
From: <sip:[email protected]:5060>;tag=xxx
To: <sip:[email protected]:5060>;tag=xxx
User-Agent: SIP UAS V.2016.xxxx
Via: SIP/2.0/UDP 192.168.0.107:5060;rport=5060;branch=xxx
v=0
o=34020000001310000002 0 0 IN IP4 192.168.0.111
s=Play
i=VCam Live Video
c=IN IP4 192.168.0.111
t=0 0
m=video 9712 RTP/AVP 96 # 9712为设备端数据发送端口
a=sendonly
a=rtpmap:96 PS/90000
a=streamprofile:0
y=0100000001
f=v/0/0/0/0/0a/0/0/0
- SIP服务器返回ACK
ACK sip:[email protected]:5060 SIP/2.0
Via: SIP/2.0/UDP 192.168.0.107:5060;rport;branch=xxx
Max-Forwards: 70
From: sip:[email protected]:5060;tag=xxx
To: sip:[email protected]:5060;tag=xxx
Call-ID: xxx
CSeq: 18467 ACK
Content-Length: 0
TCP被动
流程
注意：
- m字段指定传输方式为TCP/RTP/AVP；
- sdp信息中增加"a=setup:passive"；
- SIP服务器启动端口监听，设备发起tcp连接请求；
抓包
- SIP服务器发送INVITE请求；
INVITE sip:[email protected]:5060 SIP/2.0
Via: SIP/2.0/UDP 192.168.0.107:5060;rport;branch=xxx
Max-Forwards: 70
From: sip:[email protected]:5060;tag=xxx
To: sip:[email protected]:5060
Contact: <sip:[email protected]:5060>
Call-ID: xxx
CSeq: 18480 INVITE
Allow: INVITE, ACK, BYE, CANCEL, UPDATE, PRACK
Supported: 100rel
Subject: xxx:xx,xxx:xx
Content-Type: application/sdp
Content-Length: 211
v=0
o=xxx 0 0 IN IP4 192.168.0.107
s=Play
c=IN IP4 192.168.0.107
t=0 0
m=video 36000 TCP/RTP/AVP 96 98 97
a=recvonly
a=rtpmap:96 PS/90000
a=rtpmap:98 H264/90000
a=rtpmap:97 MPEG4/90000
a=setup:passive
y=0100000001
- 设备返回200 OK
SIP/2.0 200 OK
Call-ID: xxx
Contact: <sip:[email protected]:5060>
Content-Length: 264
Content-Type: application/sdp
CSeq: 18480 INVITE
From: <sip:[email protected]7>;tag=xxx
To: <sip:[email protected]1>;tag=xxx
User-Agent: SIP UAS V.2016.xxxx
Via: SIP/2.0/UDP 192.168.0.107:5060;rport=5060;branch=xxx
v=0
o=xxx 0 0 IN IP4 192.168.0.111
s=Play
i=VCam Live Video
c=IN IP4 192.168.0.111
t=0 0
m=video 9724 TCP/RTP/AVP 96 # 9724为设备端数据发送端口
a=sendonly
a=rtpmap:96 PS/90000 # 流数据为PS封装
a=streamprofile:0
a=setup:active # 设备为主动发送方
a=connection:new
y=0100000001
f=v/0/0/0/0/0a/0/0/0
- SIP服务器返回ACK
ACK sip:[email protected]:5060 SIP/2.0
Via: SIP/2.0/UDP 192.168.0.107:5060;rport;branch=xxx
Max-Forwards: 70
From: sip:[email protected]:5060;tag=xxx
To: sip:[email protected]:5060;tag=xxx
Call-ID: xxx
CSeq: 18480 ACK
Content-Length: 0
TCP主动
流程
注意：
- m字段指定传输方式为TCP/RTP/AVP；
- sdp信息中增加"a=setup:active"；
- 设备返回200 OK，报文的SDP信息中包含tcp监听端口；
- SIP服务器根据设备监听端口发起TCP连接请求；
抓包
- SIP服务器发送INVITE请求；
INVITE sip:[email protected]:5060 SIP/2.0
Via: SIP/2.0/UDP 192.168.0.107:5060;rport;branch=xxx
Max-Forwards: 70
From: sip:[email protected]:5060;tag=xxx
To: sip:[email protected]:5060
Contact: <sip:[email protected]:5060>
Call-ID: xxx
CSeq: 19100 INVITE
Allow: INVITE, ACK, BYE, CANCEL, UPDATE, PRACK
Supported: 100rel
Subject: xxx:xx,xxx:xx
Content-Type: application/sdp
Content-Length: 211
v=0
o=xxx 0 0 IN IP4 192.168.0.107
s=Play
c=IN IP4 192.168.0.107
t=0 0
m=video 38000 TCP/RTP/AVP 96 98 97
a=recvonly
a=rtpmap:96 PS/90000
a=rtpmap:98 H264/90000
a=rtpmap:97 MPEG4/90000
a=setup:active
y=0100000001
- 设备返回200 OK
SIP/2.0 200 OK
Call-ID: xxx
Contact: <sip:[email protected]:5060>
Content-Length: 264
Content-Type: application/sdp
CSeq: 19100 INVITE
From: <sip:[email protected]7>;tag=xxx
To: <sip:[email protected]1>;tag=xxx
User-Agent: SIP UAS V.2016.xxxx
Via: SIP/2.0/UDP 192.168.0.107:5060;rport=5060;branch=xxx
v=0
o=xxx 0 0 IN IP4 192.168.0.111
s=Play
i=VCam Live Video
c=IN IP4 192.168.0.111
t=0 0
m=video 9704 TCP/RTP/AVP 96 # 9704为设备端监听
a=sendonly
a=rtpmap:96 PS/90000 # 流数据为PS封装
a=streamprofile:0
a=setup:passive # 设备为被动接收方
a=connection:new
y=0100000001
f=v/0/0/0/0/0a/0/0/0
- SIP服务器返回ACK
ACK sip:[email protected]:5060 SIP/2.0
Via: SIP/2.0/UDP 192.168.0.107:5060;rport;branch=xxx
Max-Forwards: 70
From: sip:[email protected]:5060;tag=xxx
To: sip:[email protected]:5060;tag=xxx
Call-ID: xxx
CSeq: 19100 ACK
Content-Length: 0
- SIP服务器主动发起tcp连接
