[comp.dcom.fax] fax/modem standards?

dpm@cs.cmu.edu (David Maynard) (04/26/91)

I would like to get either a fax modem or a standalone fax with RS232 for
use with a SPARCStation.  I like the idea of a standalone fax since it could
also be used as an image scanner.  However, it seems that fax systems are in
a state of flux.  I've seen so many articles go by on different standards
being considered that I'm confused.  

Are there standards for fax modem interfaces?  If so are they commonly
followed?  What do I ask a company (e.g. GUIS) to find out whether their
system conforms to such a standard?  I expect to write my own softare and
would like it to be as portable as possible.

Will imminent new fax standards make current fax systems obsolete within a
year?  I've read posts mentioning new resolutions, etc which would seem to
imply entirely new scanning hardware.  Should I buy now or continue paying
per fax at a fax service for a few months while new products appear?  Since
I want to use tha machine as a scanner, the new resolutions would seem
important.

What I would really like is a pointer to either an article or book that
might explain the different standards efforts without requiring me to read
entire documents on how each standard works.  Technical details are okay--I
would just rather not wade through a hundred pages to find out what the
latest XW4J3 :-) standard does for me.

Thanks,
David
-- 
 David P. Maynard (dpm@cs.cmu.edu)
 Dependable Solutions & CMU ECE
 Pittsburgh, PA  15213
--

sl@wimsey.bc.ca (Stuart Lynne) (04/27/91)

In article <1991Apr26.123813.11163@fs7.ece.cmu.edu> dpm@cs.cmu.edu (David Maynard) writes:
>
>I would like to get either a fax modem or a standalone fax with RS232 for
>use with a SPARCStation.  I like the idea of a standalone fax since it could
>also be used as an image scanner.  However, it seems that fax systems are in
>a state of flux.  I've seen so many articles go by on different standards
>being considered that I'm confused.  
>
>Are there standards for fax modem interfaces?  If so are they commonly
>followed?  What do I ask a company (e.g. GUIS) to find out whether their
>system conforms to such a standard?  I expect to write my own softare and
>would like it to be as portable as possible.

Yes there are. A standard for simple fax modems called Class 1 adds a few
commands to the standard AT command set to allow sending and receiving HDLC
and raw fax data.  Called "Class 1".

And a proposed (and in flux) standard that moves some of the fax operations
into the modem (along with a bunch of timing constraints). Add's a large
(>50) number of commands to the AT command set. Called "Class 2". It's
currently being revised and hopefully we'll take it to ballot again this
summer or fall.

Aside from all this most (almost all) fax modem manufacturers have developed
proprietary interfaces to their products.

Above the modem level there is also talk of defining a "FAX API". For
example Intel's CAS architecture. 

>Will imminent new fax standards make current fax systems obsolete within a
>year?  I've read posts mentioning new resolutions, etc which would seem to

No. (I assume you mean extensions to the FAX standard and not the proposed
fax modem interface standards.) All extensions to the CCITT standards should
allow interoperation with current equipment.

>imply entirely new scanning hardware.  Should I buy now or continue paying
>per fax at a fax service for a few months while new products appear?  Since
>I want to use tha machine as a scanner, the new resolutions would seem
>important.

As always buy computer equipment when you need it. It doesn't matter when
you buy it, it will be obsoleted by new equipment within a year. If you
don't need it now wait. If you need it now and can afford it, buy it.

>What I would really like is a pointer to either an article or book that
>might explain the different standards efforts without requiring me to read
>entire documents on how each standard works.  Technical details are okay--I
>would just rather not wade through a hundred pages to find out what the
>latest XW4J3 :-) standard does for me.

So would I :-) Seriously the only way to keep track is to attend the (many)
working meetings. Although there are also some newsletters that can keep you
uptodate if you can afford them. For example Ken Krechmer from Action
Consulting makes his living by attending standards meetings and writing
summaries for publication in a newsletter. Don't have prices. He can be
reached at 415-856-8836 or 415-856-6591(fax).

-- 
Stuart Lynne	Computer Signal Corporation, Canada
		...!van-bc!sl 604-937-7785 604-937-7718(fax) sl@wimsey.bc.ca