Re: [MMUSIC] RTSP questions in regards to the control channel socket

[Magnus Westerlund <[e-mail]>]

On 2014-03-14 00:22, Craig Matsuura wrote:
> Hi this is my first time posting here.  I have a basic question about 
> how a RTSP server should handled a connect and disconnect for what I am 
> calling the control channel (connection or transport). The control 
> channel (please correct me) is what sends the DESCRIBE, SETUP, OPTIONS, 
> PLAY commands to the RTSP SERVER.
> 
> Should a server treat the first DESCRIBE connection as its session. So 
> in the case where a socket connects to a RTSP server and sends a 
> DESCRIBE, is disconnected either by the client or some failure on the 
> server should the following SETUP succeed?

No, DESCRIBE is a state less operation. If one needs a linkage between
the Describe response body and the setup, then one should use etags and
conditional requests to ensure that one is establishing the session with
a relevant session description.

> 
> Also if using a RTSP Proxy and in the same scenario, but after the 
> DESCRIBE and closing of the socket a new socket is open to send an 
> OPTIONS (for keepalive) should the following SETUP succeed?

Yes the SETUP should succeed if otherwise valid.

> 
>  From what I understood from the RFC2326 Section 1.7 RTSP State, it 
> should not matter how many connections are used to control the RTSP Stream.
> 
> 1. Control Socket is not prevent a client from connecting and 
> disconnecting to send Transport commands.

I am uncertain what you mean with the Control socket, if you means the
Socket the server listens to incoming TCP connection establishments and
their data, it needs to be accepting those comming and going.

> 2. The keep-alive for a session should not start until a SETUP command, 
> which can optional report the timeout for the session.

Exact, the keep-alive is associated with the RTSP session, not the
signalling connection used to send RTSP requests and response between
the server and client.

You might find RTSP 2.0's text on this being clearer:
https://datatracker.ietf.org/doc/draft-ietf-mmusic-rfc2326bis/

Cheers

Magnus Westerlund

----------------------------------------------------------------------
Services, Media and Network features, Ericsson Research EAB/TXM
----------------------------------------------------------------------
Ericsson AB                 | Phone  [phone]
Färögatan 6                 | Mobile [phone]
SE-164 80 Stockholm, Sweden | mailto: [e-mail]
----------------------------------------------------------------------