Jeff, I want to make sure I understand your comments.
>> Jeff... when you say "A T1 (DS1) is 1.544Mbits/sec. You'll get about
>> 1.3Mbits/sec thruput in both directions." Does that mean that just one
>> workstation at a time will see that throughput?
>
> No. The bandwidth is distributed roughly equally among the
> workstations.
>
Could the above sentence read "No. The bandwidth is distributed roughly equally
among the workstations" that are at that moment sending / receiving on the
Internet.
In other words... the active workstations share the bandwidth. True? I think
that is what you said below.

> If 10 computers / workstations
>> are at the same time doing a Microsoft update for example... are they sharing
>> that 1.3Mbit bandwidth?
>
> Yes. In theory, each workstation will get 1/10th the incoming
> bandwidth. MS Update is a bad example because of the way they do
> bandwidth limiting, but that's a diversion and not part of this
> discussion.
>
>> Are they each then downloading at 130Kb. Does it work
>> that way?
>
> Yes.
>
I'm really surprised to learn that a T1 Internet connection has these
limitations. Seems then that (except for upload) it's like having 50 or so
computers on a home DSL Internet connection. I would have thought that this
would have been un-acceptable. My "thought" is not based on technical knowledge
but I always assumed that a T1 was the ultimate way to go.
One more thing. At any given time during the work day we have about 20
computers using instant messaging. Most of the time there is not traffic but the
apps are always listening. Is that much of a load?
I am extremely grateful for the time you've spent providing all this good
information. If we don't have to run all new cable your tip will save our
company a lot of money and labor.