Section 8 : General Telecommunications & Modems

Q803: How can I tell if my modem supports 2D compression?

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How can I tell if my modem supports 2D compression?

From: Dmitry Bely <>
Subject: Re: flexfax: Q about elsa modem
Date: 16 March 2000 17:44
> i use an elsa microlink 56k basic with hylafax and the config file
> from their webpage. everything runs good but i only get 1D connections.
> the config files uses Class2.0.
> i have no use2d: no anywhere
> no corrupt info files
> i called elsa support and they do not know wether their product
> supports 2D encoding or not!?!!

You can easily get this info yourself. Issue in any terminal program (e.g. minicom) the following commands:

You will get something like
(That's what my Zyxel 1496e responded).

The parameters above are

The fifth parameter (DF) is the range of DCE-supported data compression methods according to the following table:
DFData Compression Format 0 1-D Modified Huffman (T.4)
*1 2-D Modified Read (T.4)
*2 2-D Uncompressed Mode (T.4)
*3 2-D Modified Modified Read (T.6)

So if your modem returns just (0), 1-D is the only compression format supported.
BTW, this command id valid for Class 2.0 only.

Hope to hear from you soon,

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