pretty much OT: acoustic coupling

Chuck Guzis cclist at sydex.com
Sun Mar 25 20:31:50 CDT 2007


On 25 Mar 2007 at 19:40, der Mouse wrote:

> > You can't do 56K over a strictly analog phone line--
> 
> Um, POTS phone lines *are* strictly analog, from the modem to the CO.
> 
> I wouldn't want to bet that 56K is impossible even with POTS copper at
> each end, with suitably smart probing of the signal path and adaption
> to its observed characteristics.  (Which is not to say that modern 56K
> modems can do that.)

As I understand it, that's not the way 56K works--you can hook two 
56K modems back-to-back on your workbench and they won't do 56K.  As 
I understand it, on end has to interface to a digital phone line.  
One A/D conversion allowed.  Hence, the line from you to your ISP is 
not "striclty" analog.

See:

http://www.56k.com/basics/basics.shtml

Cheers,
Chuck




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