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From: sl@van-bc.UUCP (Stuart Lynne)
Newsgroups: comp.dcom.telecom
Subject: Re: US Sprint -- A Case Study in Misinformation
Message-ID: <6203@accuvax.nwu.edu>
Date: 9 Apr 90 23:12:40 GMT
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In article <6023@accuvax.nwu.edu> mtndew!friedl@uunet.uu.net (Steve Friedl) 
writes:

>> I assume fax machines use some sort of error-correction, so anything
>> but truly horrid phone lines shouldn't affect it.

>No, not at all.  Note here that "fax" means Group III, which is all I
>have substantial experience with.

>Group III fax has neither error correction nor flow control, so phone
>lines do definitely make a difference.  The data pattern is modified

Yes and no ...

Yes: most (if not almost all) Group III machines do not have error correction. 

No: CCITT Group III specifications (as of 1988) do allow for an ECM
mode between two consenting machines.


Stuart.Lynne@wimsey.bc.ca ubc-cs!van-bc!sl 
604-937-7532 (voice)    604-939-4768 (fax)