Subject: [Megaco] Doubt in IG B.2 ABNF Syntax Specification

From: "Sundareswaram P V" <[email-masked]>
Date: Tue, 30 Oct 2001 10:15:51 +0530

Hi,
    The Definition VALUE according to the IG says that Integer, Double,Unsigned Integer all are accepteble either in decimal or Hexadecimal format.
    My question is - How will the Hexadecimal form of a Double be represented(for fractional numbers), or rather i'm not very clear of encoding and decoding of hexadecimal value for Double value.
   eg:- how to represent 17.17 in hexadecimal format for encoding or even decoding.
   Cud any one help me in this case.   

rgds,
Sundar.

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From: Francois Pinier <[email-masked]>
Date: Tue, 30 Oct 2001 08:27:16 +0100

Sundareswaram P V wrote:

> Hi,    The Definition VALUE according to the IG says that Integer,
> Double,Unsigned Integer all are accepteble either in decimal or
> Hexadecimal format.    My question is - How will the Hexadecimal form
> of a Double be represented(for fractional numbers), or rather i'm not
> very clear of encoding and decoding of hexadecimal value for Double
> value.   eg:- how to represent 17.17 in hexadecimal format for
> encoding or even decoding.   Cud any one help me in this case. rgds,
> Sundar.

    Hello everybody,

For double number representation, does it make sense to use the
hexadecimal format compliant with IEEE 754 floating point arithmetic
standard ? If so, according to the IEEE standard, the double
representation in hexdecimal of previous example will be : 17.17 -->X
"40312B851EB851EC".

If you have any comment or idea on this topic, please let me know.

    Best regards.

        François Pinier

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From: Francois Pinier <[email-masked]>
Date: Tue, 30 Oct 2001 08:27:16 +0100

Hello everybody,

    Best regards.

        François Pinier

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From: Terry L Anderson <[email-masked]>
Date: Wed, 31 Oct 2001 13:16:03 -0500

If you look at 12.1.2, or the note added to Annex A by 6.46, you will
find that "Double" is defined as a double length Integer (8-bytes) and
NOT the double length real that the term often refers to.  So there is
no issue about encoding fractions - there are no primitive types for
reals or fractional numbers.

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Terry L Anderson              mailto:[email-masked]
Tel:908.582.7013   Fax:908.582.6729
Lucent Technologies/INS/Voice Over IP Access Networks
Rm 2B-121, 600 Mountain Av, Murray Hill, NJ 07974
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From: Terry L Anderson <[email-masked]>
Date: Wed, 31 Oct 2001 13:16:03 -0500

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