Subject: Re: [rohc] RE: Clarifications for the Implementer's guide

From: "West, Mark (ITN)" <[email-masked]>
Date: Mon, 03 Jun 2002 23:22:44 +0100

Hi Peter, Lars-Erik,

The text on feedback links sounds quite reasonable.

 >
 >> 2) What does "presumed zero if absent" mean on page 88? The Arctic
 >>  ROHC participants agreed that c) seemed to be the  reasonable 
assumption,
 >>  which could be noted in chapter 4 of the  Implementer's guide.
 >>
 >>
 >
 > My proposed text is:
 >
 > "4.X.  What does "presumed zero if absent" mean on page 88?
 >
 > On page 88, RFC 3095 says that R-P contains the absolute value of
 > RTP Padding bit and it's presumed zero if absent.  It could be
 > absent from RTP header flags and fields, from the extension type 3
 > or from the ROHC packet. It's been agreed that the first case is
 > the most probable."
 >
 >

Simply on the basis of interoperability, we need to define what the 
assumed behaviour is going to be.  That is, not only should we say that 
the 'first case is the most probable', but we should state that "the RTP 
padding bit is presumed zero if absent from the RTP header flags."

(If, indeed, that's what we believe!)

Cheers,

Mark.

-- 
Mark A. West, Consultant Engineer
Roke Manor Research Ltd., Romsey, Hants.  SO51 0ZN
Phone +44 (0)1794 833311   Fax  +44 (0)1794 833433

(Yes, I do know that my disclaimer is in an attachment.  And, no, I
didn't ask for it to be that way)