Re: [AVT] Comments on draft-ietf-text-red-00.txt

[Magnus Westerlund <[e-mail]>]

Hi Paul,

comments inline:

Paul E. Jones wrote:

>Magnus,
>
>  
>
>>I have had some off-line discussion regarding the MIME registration
>>problem for text/RED. Know understanding the intention having the
>>ordering requirement on RFC 2198 being firm for the "pt" list, I would
>>propose the following text change for the "pt" list:
>>
>>"pt: a comma-separated ordered list enumerating the primary,
>>    
>>
>secondary,
>  
>
>>etc., encoding's RTP payload types in accordance with RFC 2198.
>>    
>>
>Because
>  
>
>>comma is ..."
>>    
>>
>
>There was a desire early on not to explicitly tie the MIME registration
>to
>RFC 2198.  Certainly, it is the main driver for producing the document,
>but
>it was viewed as not the only potential user of this registration.
>Thus, do
>we really want this text or just leave it as it is in the current draft?
>  
>

No, It must be tied to RFC 2198. In my recollection the opinion 
expressed was to not tie it to RFC 2793. I think we should go with the 
new text, because I find the old text confusing as it does not inform 
explicitly that about the semantics of the parameter.

>>Then only the last issue below, remains to be resolved as I see it.
>>    
>>
>
>And, how can we close on that issue below?
>  
>

I don't know really, it seems that we should be compatible with what is 
used for audio/RED. However what is really used here is not totally 
clear. Based on the examples in RFC 2198 one does rely on having dynamic 
PTs to be declared through "a=rtpmap".

What is you others opinion about this?

Cheers

Magnus

>  
>
>>Cheers
>>
>>Magnus
>>
>>Magnus Westerlund wrote:
>>
>>    
>>
>>>>>When you are in the SDP domain, you SHOULD NOT / SHALL NOT use the
>>>>>pt=content-type structure at all. As the information is available
>>>>>          
>>>>>
>in
>  
>
>>>>the
>>>>
>>>>
>>>>        
>>>>
>>>>>SDP as defined PT. Therefore you only need to reference these PTs.
>>>>>          
>>>>>
>So
>  
>
>>>>>when having SDP should you in fact remove all of these
>>>>>          
>>>>>
>pt=content-type
>  
>
>>>>>declarations and only use PTs in the list?
>>>>>
>>>>>I would also like to point out that the this declaration of
>>>>>"dynamic-payload-type "=" content-type" is not sufficiently clear.
>>>>>          
>>>>>
>For
>  
>
>>>>>RTP payload formats using parameters to configure this, this
>>>>>          
>>>>>
>string is
>  
>
>>>>>insufficient unless the parameter list can be included in the
>>>>>content-type part.
>>>>>
>>>>>          
>>>>>
>>>>Ah, I understand.  As I mentioned above, this follows the example
>>>>        
>>>>
>in
>RFC
>  
>
>>>>3555, which also does not go into discussion on this (as far as I
>>>>        
>>>>
>know).
>  
>
>>>>I
>>>>assume the reason for that was simply that the entire focus was on
>>>>        
>>>>
>SDP,
>  
>
>>>>anyway, with little focus on MIME, really.
>>>>
>>>>In any case, I can add text in this regard, but I need some
>>>>        
>>>>
>guidance as
>  
>
>>>>to
>>>>what we should have inserted to make this clearer.
>>>>
>>>>
>>>>
>>>>        
>>>>
>>>I would definitely like to have some more input from Colin and
>>>      
>>>
>others
>  
>
>>>about how this problem should be resolved.
>>>
>>>      
>>>
>>-- 
>>
>>Magnus Westerlund
>>
>>Multimedia Technologies, Ericsson Research EAB/TVA/A
>>----------------------------------------------------------------------
>>Ericsson AB                | Phone [phone]
>>Torshamsgatan 23           | Fax   [phone]
>>S-164 80 Stockholm, Sweden | mailto: [e-mail]
>>
>>
>>    
>>
>
>  
>

-- 

Magnus Westerlund 

Multimedia Technologies, Ericsson Research EAB/TVA/A
----------------------------------------------------------------------
Ericsson AB                | Phone [phone]
Torshamsgatan 23           | Fax   [phone]
S-164 80 Stockholm, Sweden | mailto: [e-mail]



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