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RE: EXI vs. ASN.1 BER

From: Taki Kamiya <tkamiya@us.fujitsu.com>
Date: Tue, 29 Sep 2009 14:44:53 -0700
To: "'John Cowan'" <cowan@ccil.org>, <public-exi-comments@w3.org>
Message-ID: <8623C0DF46EA46AA97442D617EE5C51E@homunculus>
Hi John,

I am not sure if the BER length encoding (section 8.1.3 in [1]) is that
close to the EXI Unsigned Integer encoding. The first bit in the octet tells
you whether it is in short form or long form in BER, whereas it is used to
terminate the value in EXI...

[1] http://www.itu.int/ITU-T/studygroups/com17/languages/X.690-0207.pdf

Thanks!

-taki


-----Original Message-----
From: public-exi-comments-request@w3.org [mailto:public-exi-comments-request@w3.org] On Behalf Of John Cowan
Sent: Saturday, September 26, 2009 12:28 PM
To: public-exi-comments@w3.org
Subject: EXI vs. ASN.1 BER

This is a comment on the Last Call draft of 19 September 2008.

I think it would be useful to add an editorial note to 7.1.6 something
like this:

        Note: The encoding of Unsigned Integers is the same as the
        encoding used in ASN.1 BER for lengths, except that in ASN.1
        the least significant byte appears last rather than first.

An EXI implementer familiar with ASN.1 BER might well miss this
distinction otherwise.

--
John Cowan                                cowan@ccil.org
I amar prestar aen, han mathon ne nen,    http://www.ccil.org/~cowan
han mathon ne chae, a han noston ne 'wilith.  --Galadriel, LOTR:FOTR
Received on Tuesday, 29 September 2009 21:45:45 UTC

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