David Gillett wrote:

> On  2 Dec 98 at 12:52, Jim Meagher wrote:
>
> > At your house, the modem is connected to an analog (read that as
> > voice grade) telephone connection.  At some point, the phone
> > company will convert that analog signal into a digital signal
> > (usually the main trunk line).  And -ideally- will convert the
> > signal back to an analog circuit just before it enters your ISP's
> > building.  With this perfect scenario, you should be able to
> > achieve near 56K speeds.
>
>   I think one of the stated requirements for 56K is that there NOT be
> a D-to-A conversion at the ISP's end.  They have to bring a digital
> T1 or PRI (BRI?) [or better] into a CSU/DSU rather than a bunch of
> analog lines into modems.

Someone else made a similar comment but I don't believe that it is it
true.  Yes, it
would improve the chances of reaching 56K, but I think that the T-1 or
fractional is
more a matter of economy/efficiency with the TelCo and not a part of the
56K spec.
The massive number of incoming lines for an ISP almost dictates that it
has to be digital.
(Besides, I don't think anyone makes an analog rackmount modem anymore.
[grin])

The whole reason for developing the V.90 spec, was to allow dissimilar
modems to
talk to each other at 56K.  Remember all the problems we saw when the X2
and Kflex
modems first came out.  And how we counseled people to wait and see what
type
modems your ISP gets.....

--
Jim Meagher
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