Impact of RTSP '455 - Method Not Valid In This State'?

[Arrturk]

Hi All,

Me again. You might remember me from such informative threads as 'Customer impact of a 500 Internal Server Error in WMS?'.

This time it's the 455 status code in RTSP - 'Method Not Valid In This State'.

Essentially what is happening is that an RTSP stream will be chugging along before a PAUSE is sent by the client (WMP) to the server (WMS9) via a NetCache.

Receiving the PAUSE request, the server replies as expected by stopping the stream and replying with an acknowledgement:

Code:

RTSP/1.0 200 OK
CSeq: 8
Date: Tue, 16 Jun 2009 08:59:28 GMT
Server: WMServer/9.1.1.3841
Via: 1.0 char08-stream-nc01 (NetCache NetApp/6.0.5)
Session: 3102550

The client then sends through it's Client Render Log as a part of a SET_PARAMETER request, which the server acknowledges (I have left this out).

Now here is where things get a little weird... the client should know what state the server is in (as it put it there), however the client sends yet another PAUSE request.

As you would expect (and as per RFC 2326) the PAUSE request is incompatable:

Code:

RTSP/1.0 455 Method Not Valid in This State
CSeq: 10
Date: Tue, 16 Jun 2009 08:59:31 GMT
Server: WMServer/9.1.1.3841
Via: 1.0 char08-stream-nc01 (NetCache NetApp/6.0.5)
Session: 3102550

This is then followed by the client initiating TEARDOWN of the RTSP session.

Logic dictates that the customer impact of this would be negligible as the stream would already be in a PAUSE state. So issuing another PAUSE would result in the server effectively saying "Yeah no kidding. Still Paused".

So my questions (answers or ideas on ANY of them greatly appreciated):

• What would the customer impact be of this 455 error?
• What resources are out there that describe what the impact is?
• Has anyone seen this 'double PAUSE' scernario before?
  

Sorry if this is considered begging... if it's any consolation, if/when I find the answer I post it in here so that other people looking for same information are helped

Cheers!

RT

[Arrturk]

Well I haven't been able to replicate the issue, but I have documented evidence that the 455 status code is not customer impacting in the scenario that was mentioned above.

Seeing that I'm sceptical as to how many people actually read these forums, if you desperately want more information, just post in here and I'll reply (I'm subscribed).

Cheers!

RT