From: ketil@edb.tih.no (Ketil Albertsen,TIH)
Subject: Re: PC-NFS PPP Serial/ISDN driver wanted
Organization: T I H / T I S I P 
Posting-Front-End: Winix Conference v 92.05.15  1.20 (running under MS-Windows)
Date: Mon, 25 Jan 1993 15:31:09 GMT

In article <2936706683.1.p00136@psilink.com>, "Bob Larribeau" 
<p00136@psilink.com> writes:

>In the U.S. (unlike most of the rest of the world) the NT1 is customer 
>equipment and not network equipment.  It is the customer's 
>responsibility to purchase and install the NT1.
>
>The reason for having a U interace in the ISDN bridge is that it can 
>reduce cost by eliminating the need for the U interface to T interface 
>conversion and then the T interface to Ethernet conversion by converting 
>directly from the U interface to Ethernet.
>
>Note that this is not necessarily the same as integrating the bridge 
>with an NT1.  NT1s have an S/T inteface and support the passive bus.  
>The U interface bridge would not require this function.
>
>The primary advantage of having an NT1 is that it permits support for 
>passive bus and the ability to connect multiple devices on an ISDN line. 
>However given the limitations of NI-1 in supporting B channel 
>contention, this is not a strong reason.  These limitations are supposed 
>to disappear with NI-2.
>
>In the U.S. there are ISDN telephones and TAs with U interfaces.  It 
>does represent the lowest cost for connecting to an ISDN line.  A voice 
>only, U interface ISDN telephone is in the $200 price range.

Pity me. I am a European. I can't select from a whole crowd of Ether-to-
U-variant-1 and Ether-to-U-variant-2 and ... praying to God that I'll
get the right one THIS time. Whatever Ether-to-S/T I buy, it will fit 
into my ISDN network. How boring. How unimaginative. How unchallenging.

Pity me. If in the future the phone company replaces the copper U
with a fiber based U, I am not forced to stimulate economy by buying
a new Ether-to-U bridge - the old one still works. The economy might
come to a standstill that way.

Pity me. On my S/T connection, I hook up fax machines, phones, PC ISDN
cards and other equipment side by side, rather than ordering a whole
bunch of ISDN lines, one for each. I must have misunderstood the "IS" 
in "ISDN" - the idea is to do it on different but similar connections, 
isn't it?

Pity me. On my ISDN connection I can transfer sound and files and E-mail
and what have you, I do not have a dedicated voice solution. I probably
have a very inefficient solution.

Pity me. The standard components of my standard ISDN system honors the 
ISDN standard. So if I want non-standard (with respect to ISDN) equipment
to interface with a unstandardized U network connection, in *my* world
there is none of ISDN left. In *your* world, you can continue calling it
ISDN although there is no place in the system where actual ISDN standards
are employed fully, no place where equipment that 100% follows the ISDN
standards can be plugged in.

Pity me. I cannot get a standard ISDN phone with all the added ISDN
functionality and flexibility as cheap as your socalled ISDN phone 
that really has nothing to do with ISDN. I will have to pay a little
bit more (at least until the volume comes up because in Europe, we
will all be using the same standard), but I will get A LOT more.

Or maybe I don't need all that pity, after all... 

:-) :-) :-) :-) :-) :-) :-) :-)  (-: (-: (-: (-: (-: (-: (-: (-:
Newsgroups: comp.protocols.nfs