Bob Breed wrote the following to Craig Ford, and I quote (in part):
-=> Note: Copied from HS_MODEMS by WIMM/2 1.31
   BB> I have a general area question about all this 56k stuff. I retired
   BB> from  the telco in 1984, so know about T carrier systems etc. But
   BB> from what I  read about these 56k modems, it sounds like they haul
   BB> the 4 wire end of  a T channel out to the ISP?
In the case of supporting 56K links, it is an absolute necessity (at the very 
leat, a trunk side ISDN BRI is required). It is _very_ rare for an ISP of any 
repute to rely on banks of discrete modems these days. The typical ISP setup 
now has one or more T carriers terminated in Ascend, Livingsston, 3COM Totoal 
Control boxes.
 BB> Splitting a T system was unheard of in my days. (I retired in
 BB> 1984.) I  know we do it now, as many business buy enough channels
 BB> to warrant the  cost of the T span. I further understand that these
 BB> systems use other terminal devices than those made by WECO.
Western Electric has long since been supplanted as the primary vendor of of 
CO line cards.
 BB> I see no way of preventing the A/D conversion on the ISP/User
 BB> direction  if they don't have access to the 4w side of the channel?
They do.
Regards....
Craig
aka: cford@ix.netcom.com
   : craig.ford@2001.conchbbs.com
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