[Asterisk-Users] Asterisk mangling faxes
faxguy at howardsilvan.com
Wed Mar 10 12:50:55 MST 2004
On 2004.03.10 10:18 Jim Sneeringer wrote:
> Do you know if there is other fax software that supports ECM?
Please forgive me for butting in on this thread, but I can't resist
Almost all fax software, including your WinFax 7.0, that supports Fax
Class 2, Class 2.0, or Class 2.1 will usually therefore support ECM
when the modem (DCE) itself supports ECM in those Fax Classes. This is
because the DCE does the ECM protocol work, and the software (DTE)
doesn't really notice the difference. Using Class 2 for faxing you are
mostly subject to the mercy of the modem manufacturer for quality, so
any bugs must usually be fixed in firmware.
Modems that I know of that support ECM in some fashion in Class
2/2.0/2.1 are the MultiTech 5634 V92 family (MT5634ZBA-V92, ISI5634,
etc.), the Digi AccelePort RAS, and the Eicon Diva Server. There
probably are a few more, but yes, this is a very short list. Most
modems do not support ECM in their Class 2 firmwares.
However, many (although not all, dare I say most?) modems support Fax
Class 1 or Class 1.0. In this mode the faxing is heavily dependent
upon the DTE and thus the support or lack of support for ECM comes from
the fax software. Your average fax software that comes on a CD bundled
with your modem is not going to support ECM. Symantec (your WinFax
people) recently purchased the rights to Procomm Plus (yes, if you're
an old BBSer you may have this on your shelf), which does support ECM
in Class 1, so maybe Symantec will get that ECM technology into WinFax
eventually. In the open-source world, HylaFAX now supports ECM in its
Class 1 implementation in its current CVS HEAD (to someday become
I don't know of many other Class 1 Fax Softwares that support ECM.
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