Confusion regarding RTSP over HTTP tunneling

Question

I had an confusion of which I searched but didn't get any answer.

I am streaming a video file using RTSP over HTTP tunneling then when I see the wire-shark to see the packets source and destination and protocol I saw a UDP protocol although i am using RTSP over HTTP tunneling.

Can any one tell me why don't I see the TCP protocol instead of UDP protocol for packets being sent from source to destination?

Solution 1

RTSP is a network control protocol. According to Wikipedia,

The default port for the RTSP protocol is 554 for both UDP (deprecated and very rarely used) and TCP transports.

Conclusion: UDP or TCP will be used, depends on which server you use and settings.

Solution 2

RTSP sets up RTP streams for streaming the video and audio. They are probably being sent over UDP instead of tunneling over the existing TCP connection.

Just because RTSP is being tunneled over HTTP doesn't guarantee that the RTP streams will be configured to use the same socket. It's up to the client to request the transport, but you can change the server to only support the interleaved transport. See this answer https://stackoverflow.com/a/3536969/759140

Comments

[Ajinkya]

we are using RTSP over HTTP Tunnelling then why wireshark shows the UDP protocol

[Raptor]

RTSP over HTTP tunneling doesn't mean TCP will be used. As TCP has more overheads than UDP, real time streaming will prefer to use UDP as less traffic will be made. By the way, why do you want to use TCP ? Try blocking UDP of port 554 and see if LIVE555 will switch to TCP.

[Ajinkya]

how to block UDP of port 554 please guide

[Raptor]

it's a firewall setting. depends on which firewall you use.

[Ajinkya]

i am using in built firewall in window 7

[Raptor]

run firewall.cpl . Deny Outbound UDP at port 554 in your LIVE555 machine.

[Ajinkya]

sir what i want is when i stream the video from my streamer it should show that tcp packets are being sent to the destination instraed od UDP in wireshark

[Ajinkya]

sir if i did "run firewall.cpl . Deny Outbound UDP at port 554 in your LIVE555 machine" then there is no streaming

[Ajinkya]

let us continue this discussion in chat

[Ajinkya]

sir i am using 2 live555 programs "testMpeg2transportstreamer" in test directory of live 555 and proxy server in proxy server directory of live 555,to the proxy server program i am giving the url of "testMpeg2transportstreamer" rtsp server and now can i send the C->A: SETUP rtsp://audio.example.com/twister/audio.en RTSP/1.0 CSeq: 1 Transport: RTP/AVP/TCP;unicast;client_port=3056-3057 to "testMpeg2transportstreamer" from proxy server please guide

[vipw]

You'll probably want to use interleaved (section 10.12 in rfc 2326)

[Ajinkya]

sir but the biggest problem is how to send the SETUP request from proxy server to testMpeg2transportstreamer

[Ajinkya]

sir i made a setup command from the client to server the setup command is like this Sending request: SETUP rtsp://192.168.15.192:8554/STREAMERUltra/track1 RTSP/1.0 CSeq: 4 Transport: RTP/AVP/TCP;unicast;interleaved=0-1 Received 84 new bytes of response data. Received a complete SETUP response: RTSP/1.0 461 Unsupported Transport CSeq: 4 Date: Thu, Jan 10 2013 06:32:42 GMT and receive the shown response but didn't get any stream can you guide firther

[vipw]

It appears your RTSP server doesn't support interleaved transport.

[Ajinkya]

sir can you tell me one thing that rtsp over http tunnelling mean all packets will be sent using tcp?

[Ajinkya]

sir if RTSP over HTTP tunneling doesn't mean TCP will be used then whats the use of RTSP over HTTP tunneling and wht will it do?

[vipw]

@Ajinkya it definitely does NOT mean that. It only means that the RTSP packets will be sent over the HTTP connection. The data packets will be sent using RTP. They will be sent according to the Transport header of the SETUP message.

[Ajinkya]

so wireshark will show UDP as a protocol for the packets being sent

[Ajinkya]

is there any way to sent the tear down request from proxy server to back end server

[Ajinkya]

is there any way to sent the tear down request from proxy server to back end server

[Ajinkya]

plz reply on this sir stackoverflow.com/questions/14752569/…

[Ajinkya]

please reply this query sir stackoverflow.com/questions/14752569/…

[Ajinkya]

please reply on this stackoverflow.com/questions/14811574/…

[Ajinkya]

sir please reply on this stackoverflow.com/questions/14811574/…