Email address obfuscation in effect -- please
click here to turn it off.
[
Date Prev][
Date Next][
Thread Prev][
Thread Next][
Date Index][
Thread Index]
<grin> Plagiarize away! Knowledge like this was meant to be shared anyway.
Hoarding it just holds people back. <shrug> Mention me on the page,
though, if you feel like having a "For clarification or other questions"
link (and you don't point it to yourself) <grin>. But I don't mind doing
it, and I'd be honored to be quoted.
Thanks!
--J
> -----Original Message-----
> From: Buford, Rick [mailto:EMAIL:PROTECTED]
> Sent: Monday, November 29, 1999 8:23 AM
> To: EMAIL:PROTECTED
> Subject: RE: [UUG/MLUG] Various networking questions:
>
>
> As many times in the recent past as this question has been
> asked, I was
> thinking about trying to do a real simple page with some
> decent diagrams so
> we could simply refer people to it rather than explaining it
> each time. Do
> you mind if I plagarize you so I don't have to re-write it again?
>
> Rick Buford
> Chief Clerk
> Medical Records - Transcription
> DC042.06 / 884-7452
> "A bus station is where a bus stops. A train station is where a train
> stops. On my desk I have a workstation...."
>
>
> |-----Original Message-----
> |From: McNutt, Justin M. [mailto:EMAIL:PROTECTED]
> |Sent: Sunday, November 28, 1999 2:00 PM
> |To: EMAIL:PROTECTED
> |Subject: [UUG/MLUG] Various networking questions:
> |
> |
> |There have been various networking/cabling questions on
> |here lately. Here
> |are some of the answers, answered ad nauseum <grin>:
> |
> |1) There are several kinds of Ethernet over CAT5. One is
> |10BASE-T, which
> |uses pairs 1-2, and 3-6. Another is 100BASE-TX which is
> |100Mb and uses the
> |same four wires as 10BASE-T. Another is 100BASE-T4 which
> |uses all four
> |pairs in CAT5, and the last is 100BASE-T2, which uses the
> |same four wires as
> |10BASE-T, but can be used with CAT3 cabling (lower quality).
> |
> |Only 10BASE-T, 100BASE-TX, and 100BASE-T4 can use autonegotiation.
> |100BASE-T2 has no standard for that yet. 10BASE-T and
> |100BASE-TX are the
> |most common and use only four of the eight wires available
> |in standard CAT5.
> |
> |2) If you are going to wire your house, use plenum cable
> |(has to do with
> |the coating - not the shielding - and fire regulations),
> |and keep it well
> |away from power lines. The three feet mentioned before for
> |unshielded
> |cabling sounds about right.
> |
> |3) You can use any single pair of CAT5 for a phone line,
> |for up to three
> |lines in a jack (RJ11 jacks have only six leads). This is
> |a good idea since
> |the twisting in CAT5 gives you better signal quality for
> |your local loop
> |(the wiring in your house).
> |
> |4) You can *try* running 10BASE-T or 100BASE-TX over four
> |of the wires in a
> |CAT5 cable, and running phones over one or both of the
> |other pairs. As long
> |as the jacks are a bit apart, I can't see that there would
> |be much of a
> |problem, since they use such vastly different frequencies.
> |Remember that
> |even a 28.8kbps modem is actually running at 2400 *baud*,
> |but uses phase
> |modulation to transmit many bits per baud. So you have the
> |modem at 2400Hz
> |and the network at 125MHz (100Mb Ethernet). The signal
> |filters in each set
> |of devices should keep out the noise (if any) from the other.
> |
> |Of course, that's theory. It *should* work, but you'll
> |have to try it.
> |
> |5) All you have to do to hook two Ethernet computers
> |together is make (or
> |buy) a crossover cable. They can be purchased
> |commercially, you just have
> |to ask for them sometimes.
> |
> |Here's the instructions for making your own Ethernet
> |crossover cable (this
> |is long):
> |
> |You need a CAT5 patch cord, a crimper with an RJ45 die, and
> |the appropriate
> |RJ45 tips. Pay attention to the type of cable you have
> |because there are
> |different tips for solid cable and stranded cable (is the
> |copper wire a
> |single solid wire or a lot of little wires?). Make sure
> |you have the right
> |die for the tips you're using. For computer-to-computer,
> |stranded cable is
> |recommended.
> |
> |Those parts are available from catalogs, and probably from
> |Insight.com if
> |you poke around a bit.
> |
> |For 10BASE-T or 100BASE-TX, look at one end of the cable.
> |Write down the
> |colors of the wires *in order* as you see them. Here's
> an example:
> |
> |Pin 1: Orange
> |PIn 2: White-Orange
> |Pin 3: Blue
> |Pin 4: White-Green
> |Pin 5: Green
> |Pin 6: White-Blue
> |Pin 7: Brown
> |Pin 8: White-Brown
> |
> |Note that 3 and 6 are a pair and 4 and 5 are a pair. They
> |don't just go
> |1-2, 3-4, 5-6...
> |
> |Anyway, chop off the connector at the other end. Then,
> |using the example
> |colors above (you'll have to modify these instructions for
> |your cables), you
> |would insert the wires at the other end into one of the
> |RJ45 tips in this
> |order:
> |
> |Pin 1: Blue
> |Pin 2: White-Blue
> |Pin 3: Orange
> |Pin 4: White-Green
> |Pin 5: Green
> |Pin 6: White Orange
> |Pin 7: Brown
> |Pin 8: White-Brown
> |
> |Note that *pair* 1-2 gets swapped with *pair* 3-6. Now the
> |transmit pair on
> |one side goes to the receive pair on the other side, and
> |vice versa. This
> |is because usually you have a concentrator (or switch) do
> |this for you, but
> |since you're going to plug directly into the interface at
> |the other side,
> |you have to swap the wires yourself.
> |
> |Anyway, make sure you untwist the wires as little as
> |possible getting them
> |into the RJ45 tip, and crimp it with the crimper. Then
> try it out!
> |
> |To make a Token Ring crossover, it's pretty much the same
> |thing, but you
> |have to crossover pairs 3-6 and 4-5 instead. I don't know
> |about 100BASE-T4,
> |and I don't think you *can* crossover 1000BASE-T (Gb).
> |100BASE-2 should be
> |the same as 100BASE-TX. I have the specs on all of those
> |somewhere if
> |somebody's really interested. <grin>.
> |
> |Clear as mud? Hope some of that helps!
> |
> |--J
> |
>