Connect Two Computers
With Ethernet Cords
Ethernet is by far the most common
method today for physically connecting two computer on the same network. There
are three slightly different types of Ethernet cords available, which makes
things slightly more complicated, but they’re all compatible with each other,
so you don’t need to worry too much about buying the wrong cord.
All Ethernet cords end with an adapter
that looks like a big U.S. telephone adapter. This adapter is called an RJ45
(U.S. telephone adapters are RJ11). At the end, it contains 8 parallel metal
pins.
Most Ethernet cords are colored blue,
although they can come in any color. Watch out for Ethernet cords colored
yellow or red—these may be a special type of Ethernet called a crossover cable.
There are three different varieties of
Ethernet cable. You can always tell which type of cable you have by reading the
text printed on the cable. You have to look hard, as often the printing is in
small, faint letters, but you should see something like the following text
taken from an actual cable: “E111018 (A0l). Type CM 75°C 24AWG (UL) LL92833 CSA
TYPE CMG 60°C SUN MICROSYSTEMS 180–1529–02 CATEGORY 5”.
Note the last part says, “CATEGORY 5”.
It may also have said “CAT 5” or “CAT–5”, but it would mean the same thing.
Also the CAT–5 designation can appear anywhere in the text, not just at the
end. Besides CAT–5, there is also CAT–5E and CAT–6. Here are the differences
between them:
- CAT–5 was the fastest
usable Ethernet cable for over a decade. But recently, faster routers have
been able to use better cables to provider faster speeds to computers. If
you’re just starting a home network, you’ll be fine using CAT–5 to connect
two computers.
- CAT–5E is used in the
current fastest Ethernet routers—it’s about 10 times faster than regular
CAT–5. The extra speed comes from building the CAT–5E cables to a more
precise specification that reduces electromagnetic interference.
- CAT–6 is also used in
the current fastest Ethernet routers, but no current router can transmit
fast enough to use all of the bandwidth available in CAT–6. Because of
this, many companies use CAT–6 in their internal wiring so that they don’t
need to rewire when faster routers come out.
When you go to buy Ethernet cords, it
doesn’t matter which you buy unless you need the fastest speeds. If you have
spare cash and you want to best performance, buy CAT–6. If you’re frugal and
don’t do anything special on the Internet, buy CAT–5.
One thing you should always do is buy
pre-made CAT–5 cords. Do this even if you’re an electrician familiar with
making your own cords—Ethernet cords (especially CAT–6) are very hard to wire
without damaging their electromagnetic shielding.
