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Date:      Fri, 15 Sep 1995 09:10:51 -0700 (MST)
From:      Terry Lambert <>
To: (Brian Litzinger)
Subject:   Re: Looking for ISDN PRI solutions
Message-ID:  <>
In-Reply-To: <> from "Brian Litzinger" at Sep 15, 95 02:15:08 am

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> I realize that at first glance this message might be more appropriate
> to a different forum, however, I've already been to those forums and
> know those answers.

Personally, I recommend *against* ISDN.  Mostly because the tarrif's
allow them to start charging outrageous connect charge rates (upwards
of $600/month for a 1/2 circuit, if connected 24/7).

Amancio Hasty is probably one of your best bets.  He runs an ascend
pipeline and talks about it all the time.  8-).

In an interesting related note, TCI is installing fiber optic to the
home lines in 100,000 homes in Southern California.  This is phone
and cable and full ethernet speed to the net.  If you can get in on that,
it seems a good deal.  Contact TCI for more information (not me).

AT&T has been running tests of data delivery systems on the East Coast
using POTS lines.  Apparently, if you are in a location with a DV100,
DV200, or 5ESS or better switch, they have a card that goes in place
of the ISDN card in the switch and does 6Mb/S out an 4Mb/S in.  Until
the inter-LATA connections go in, though, the back channel will be
limited to 64k (ISDN) speeds at the switch (ie: the 4Mb/S is not going
to be available immediately).  For those who follow HDTV standards, this
is sufficient forward channel for 2 HDTV video-on-demand sessions
simultaneously, assuming the US's digital HDTV standards.  They give
you a card for your machine when you get this.

If the primary reason you are doing this is site-to-site at ISDN speeds
and downloads from the net, this might be an option.  Contact AT&T for
more information (not me).

Both of these would probably be bad for putting up a web server (for
instance) but so would most ISDN.

> Basically, my company is about to spend tens of thousands of dollars
> purchasing ISDN router equipment.  We have had in for evaluation
> Combinet, Ascend, Network Express, CISCO, and have been relatively
> dissatisfied with the results.

If neither of the above is an option, there are two other options that
aren't necessarily "real" ISDN.  The first is Frame Relay.  I recommend
Frame Relay over ISDN where possible because it is impossible to put
a connection/connection duration tarrif on Frame Relay, whereas most
phone companies intend to bill time on ISDN.  I prefer flat rate.  If
you go to Yahoo on www and look under ISDN, go to the ISDN page, and
look at the tarrif chart, you'll be able to see if this is for you or

The second option uses ISDN equipment and depends on you sharing a
switch between your locations.  You get Centrex lines between your
locations, and use ISDN DOVBS (Data Over Voice Bearer Service) modems
to connect at 64k between the locations.  Centrex is a flat rate not
tarrif'ed service.  In some US West areas, they call it "Centron" or
otherwise vary the name so as to increase your phone bill by upping
their literature and training costs (at least that the reason I suppose
they have for non-uniform naming).

> So what am I looking for?
> I want a card or a router/bridge that allows us to offer PPP
> connections via ISDN B channels.
> I want to drag in a 24/30 B channel PRI and plug it into my FreeBSD box.

There was a recent post to the list about an Isoethernet card.  Although
not released yet, it supposedly supports regular ethernet and 96 B channels
simultaneously.  It looks like just the ticket, but you'd need to write a

> I then want software that allows me to run PPP over each of the
> B channels to whomever might dialin and has the appropriate 
> authorization to connect. I also want a log of connection times.

Consulting or in house programming required.

					Terry Lambert
Any opinions in this posting are my own and not those of my present
or previous employers.

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