Subject: [AVT] AW: draft-kreuter-avt-rtp-clearmode-00.txt

From: Kreuter Ruediger <[email-masked]>
Date: Fri, 18 Oct 2002 16:36:49 +0200

thanks for your comments
see some answers below

Regards, Ruediger Kreuter
[email-masked]
phone +49 89 722 62553

> Von: Tom-PT Taylor [mailto:[email-masked]]
> Gesendet: Donnerstag, 17. Oktober 2002 19:09
> An: [email-masked]'
> Cc: [email-masked]'
> Betreff: draft-kreuter-avt-rtp-clearmode-00.txt
> 
... (I would like to postpone an answer to the
     content type issue - needs some internal 
     discussion for that)

> My third point is that the layer under RTP has not been 
> specified.  Is that
> intentional, or did the author assume UDP?

RTP usually will be used on top of UDP, but may be
used on top of other protocols too. CLEARMODE should 
not/does not depend on the protocol(s) beneath RTP.

Basically chapter 2 of 
draft-ietf-avt-profile-new-12.txt
should apply to CLEARMODE too.

In a VoIP network CLEARMODE shall be used like
a voice codec, e.g. PCMA. Therefore the same
mechanism shall be used to differentiate between
RTP over UDP versus RTP over something else, if
necessary. 

> 
> A related point is that encoding considerations are too 
> restrictive.  They
> should say that transport over TDM is also applicable 
> (besides transport
> over RTP).

In a TDM network ISDN data will be transported 
as is; i.e. as an unframed byte stream. There 
is no need for packetization.
The major attribute of CLEARMODE is an unrestricted 
(i.e. untouched) packetization of an incoming byte 
stream. So IMHO it is not applicable for transport 
over TDM.

Besides that, my intention was to generate a profile
for CLEARMODE similar to RFC1890. This assumes to
have RTP as the underlying transport protocol.
Otherwise it wouldn't be in the scope of AVT, would it?

> 
> Finally, it would be nice if this could be extended to N x 64 
> kbit/s, but
> not at the risk of the basic proposal.

You mean Nx64kbit/s should be compatible to the way
CLEARMODE is used today in VoIP networks ?
I would agree with that.

> 
> Tom Taylor
> [email-masked]
> Ph. +1 613 736 0961 (ESN 396 1490)
>  
> 
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