This article introduces the RTSP modes supported by SRX.
There are three modes in RTSP:
- Control channel uses TCP, media channel uses UDP.
- Control and media channel use same TCP channel(interleave mode).
- Control and media channel use different TCP channel.
Currently, ALG RTSP supports mode 1 and mode 2 (in 11.2 need extra configuration).
SRX does not support mode 3 yet. If customer is really using mode 3, then it should be new a requirement for ALG.
Sample packet capture for mode3:
No. Time Source Destination Protocol Length Fin Info
1285 45.731724 192.168.1.200 172.16.0.100 RTSP 174 Not set SETUP rtsp://172.16.0.100/live.006 RTSP/1.0
Frame 1285: 174 bytes on wire (1392 bits), 174 bytes captured (1392 bits)
Ethernet II, Src: Dell_57:4c:34 (5c:26:0a:57:4c:34), Dst: All-HSRP-routers_01 (00:00:0c:07:ac:01)
Internet Protocol Version 4, Src: 192.168.1.200 (192.168.1.200), Dst: 172.16.0.100 (172.16.0.100)
Transmission Control Protocol, Src Port: 51255 (51255), Dst Port: rtsp (554), Seq: 135, Ack: 197, Len: 120
Real Time Streaming Protocol
Request: SETUP rtsp://172.16.0.100/live.006 RTSP/1.0\r\n
CSeq: 2\r\n
Transport: RTP/AVP/TCP;unicast
Authorization: 0731457378-01-20\r\n
\r\n
Real Time Streaming Protocol
Data (1 bytes)
No. Time Source Destination Protocol Length Fin Info
1286 45.734743 172.16.0.100 192.168.1.200 RTSP 170 Not set Reply: RTSP/1.0 200 OK[Unreassembled Packet]
Frame 1286: 170 bytes on wire (1360 bits), 170 bytes captured (1360 bits)
Ethernet II, Src: Cisco_3b:09:00 (00:1b:53:3b:09:00), Dst: Dell_57:4c:34 (5c:26:0a:57:4c:34)
Internet Protocol Version 4, Src: 172.16.0.100 (172.16.0.100), Dst: 192.168.1.200 (192.168.1.200)
Transmission Control Protocol, Src Port: rtsp (554), Dst Port: 51255 (51255), Seq: 197, Ack: 255, Len: 116
Real Time Streaming Protocol
Response: RTSP/1.0 200 OK\r\n
CSeq: 2\r\n
Date: 07/04/13 10:06:31\r\n
Session: 12407
Transport: RTP/AVP/TCP;unicast;server_port=556
[Unreassembled Packet: RTSP]