From plaut@novell.math.utk.edu Thu Oct  9 10:31:21 1997
Subject: ISDN (High speed data) phone lines

I just got my ISDN phone line up and running; several faculty
have been wondering about how this works, so I'll give a
summary here.

The ISDN line is a single phone line that handles voice and
data for two phone numbers. The information is sorted in your
house by an ISDN modem, and sent to two phone jacks in the 
modem or to your computer.

What you need is:
1. an ISDN line to your house (about $45 to install, 
   and about $30/month) through Southern Bell, 
2. an ISDN modem (about $250 through UT, but only $95 for 
   students paying the technology fee), 
3. access to UT's modem pool ($39/semester for students, 
   $55 for faculty), and 
4. an ISDN phone jack ($5 at Radio Shack if you install it 
   yourself --$100 or so if the phone company installs it). 

If you need very high speeds (128K) you can use both lines
simultaneously for data (this is called PPP), but you have 
to pay an extra access fee to UT ($10 or so?). Even using 
one line seems fast.

To order ISDN service from Southern Bell, call 1-800-858-9413. 

Information about buying UT access and the modem can be found at
	http://www.tns.utk.edu/student_services/era.html  
When you buy the access, you get software and a readme file 
with step-by-step instructions for setting up the computer and 
modem.  However, there is little information about getting the 
phone lines set up, and so I will describe what you need to do. 

In our case, we decided to get rid of our old phone line 
(saves about $20 per month), and gave our old phone number to 
one of the two new ISDN lines. The disadvantage of doing this 
is that if the power goes out (and you don't have a battery 
backup for your modem) or if your modem dies, then your phones 
don't work. 
Also, if you want to use PPP then all of your (two) phone lines 
are tied up.  However, you can turn PPP on and off--and so only 
use it when you are downloading big things.  

At any rate, this is what you need to do to set this up: 

1. First, call to make sure you can get an ISDN line, 
   and order it. 
2. Then get the modem and access from UT. 
3. The wiring can be done as follows. I'm assuming that the 
   phone jack you now use for your computer has only one line 
   on it currently, but the usual four wires--red, green, 
   yellow, black, with the red and green for the current phone 
   line, and the yellow and black unused.  
   When the ISDN line is installed (and they have to come 
   to your house to do this, so you will know when that is), 
   attach the green incoming wire to the yellow wire leading 
   to the jack, and the red incoming wire to the black. 
   Open the existing jack at the computer, and attach a new 
   phone wire to the black and yellow wires that now go to 
   the ISDN line. Attach the green to the yellow, and the red 
   to the black. 
   At this point, you should have a phone wire coming out of 
   the phone jack, and the green wire should lead to the green 
   ISDN wire, and the red to the red ISDN wire.  Now just wire 
   up the ISDN jack next to the old phone jack--green to green 
   and red to red. 
   Plug in the ISDN modem, and get it up and running with your 
   computer (your computer configures it). 
   Plug in a phone to each of the phone jacks in the modem to 
   make sure the two phone lines are working. If you want to 
   keep your old (and now third) phone line, then your are done. 
   If you want to get by with just the ISDN lines, then 
   disconnect your other phones (at the outside box)
   --usually this means unplugging a wire from a jack at the 
   outside box. Now run a standard phone line from one jack on 
   the back of the modem to the old phone jack by your computer.
   The rest of the phones in your house should now all be 
   hooked up to that one phone line coming out of the modem. 
   Attach another phone or fax machine to the other phone jack 
   in the back of the modem. Call the phone company and have 
   them disconnect your old phone number. 
   Call the ISDN people (above number)  and have them assign 
   your old phone number to your first ISDN number.

By the way, the UT technical support has been very good 
(I had a problem because I hadn't disabled PPP, and it was 
tying up both my phone lines without giving me any advantage 
because I had't paid for PPP at the UT end).