An ISP of their own (was RE: [rescue] Being jobless)

[Stephen Sandau]

> >>> The old T1 in the last building just arrived as 4 copper wires from 
> >>> the demark just like the phone lines. Dunno what "format" that was, 
> >>> but there was no internal electronics at all..
> >> That would be HDSL.  1.5 megabits over two pairs, 2 megabits over 3
> >> pairs, maximum range about 20,000 feet.
> >
> > I thought it was not, since the HDSL we have requires a box on the 
> > wall in our office. the old setup had 4 copper wires that came in off 
> > the pole and went right into a CSU/DSU.
> 
>    It's not.  HSDL didn't exist in 1972, and T1s sure did.  T1/DS1 is a 
> baseband digital protocol that runs relatively high voltages (compared 
> to POTS lines) over bare copper.

Now that I think about it further, I believe that the old 4-wire data circuit 
in the old building was only a 56K connection. It was installed in the early 
90's I think. That would also explain the part about it plugging into a CSU/DSU 
instead of a TSU...

The higher-voltage thing may have been how the 56K workd as well...

Steve


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