I manage a network that is based off of a T1 with around 20 computers;
the network is growing everyday  At the point when we reach 24
computers, will we have a problem?  Will adding routers (as oppose to
switches and hubs) to the infrastructure prevent this?  If not, what
will the result of the channel overload be, and is there a work around?

[I think the core question, at the center of my larger question, is
what exactly is a channel, and what does it mean to be limited to 24
channels? For instance, if I have one computer that is loading 24
webpages from different servers simultaneously, is that 24 channels? 
What if I have 24 computers loading 2 webpages each, is that 48
channels?]

---

Clarification of Question by gr8fuljeff-ga on 07 Jun 2005 22:44 PDT

I also would appreciate a future reading reccomendation that would
offer me both a variety of networking information as well as more
information about T1s specifically.  In other words, either a good
book or website which offers a begginning guide to networking.

Are you referring to Internet access via your T1?

I think you may be confusing technologies.  The T1 "line" that comes
into your building (depending on _its_ technology) probably has 24
individual pairs of wires.  Where I work, the T1 we have has 24
voice-grade lines that combine into one "fatter pipe".

You'll have a router that connects your computer network to your T1
line.  Depending upon the setup of your internal computer network you
can have a (virtually) unlimited number of computers use the T1 for
internet access.

The 24 channels you are referring to are 'transparent' to the users.
The T1 technology uses 24 channels to transmit the signal from your
building to your provider but these channels are combined together to
provide you the total speed of your T1.
When you download something at full speed, you can notice that the
speed of download is the one of a full T1, meaning that it is not 1
user= 1 channel, but all users=all channels.
Basically, you should not worry about channels when it comes to data.
You basically have a 1,544Kbps symetrical (same speed download/upload)
that can be shared up to the numbers of cables you can put on your
switch (of course it s always possible to add more swithces for more
users)
The channel division can be a relevant information if you use your T1
also for the voice lines (phone). each line uses one channel, which
means your data line get slower every time a line is used for phone
(by exactly 1,544/24 for each line occupied)

so basically a channel is a digitized cable that can be used for a
voice line or data up to 1,544/24 Kbps. a T1 line is a tube large
enough to contains 24 of these channels, so that means 24 phone lines
or a combined total of 1,544 Kbps ( the router combines these channels
together for data to add the speed).

It does not matter how many users you have.  you will see a comparable
decrease of speed when you add your 25th user than when u added your
21st

Previous comments on tech are right-on!  24 is no magic number at all.

You'll want to make sure your network is switched for internal network
performance (not cheap hubs) but that is unrelated to your T-1.  We
have the 22 people on our T-1, heavy internet users, and it is quite
fine.  We are heavily using it though.

Your use of the T-1 will be primary concern.  You should monitor (or
as your ISP for reports) the utilization of your T-1 to see how you
are doing.