RE: [UUG/MLUG] Various networking - extra

["McNutt, Justin M." <EMAIL:PROTECTED>]

One other thing about running voice and data over the same *cable* that I
just thought of:

While it's true that the two systems use completely different frequencies,
Ethernet doesn't use voltages higher than about 5.0V, but when your phone
rings, that's a 90V signal that rings the phone.  Again, somebody's going to
have to try this out, but I'll bet that if you use the same cable for both,
things works just fine most of the time, but the network goes to hell when
the phone rings <grin>.

--J

> -----Original Message-----
> From: Roberts, Michael J. (IATS) [mailto:EMAIL:PROTECTED]
> Sent: Sunday, November 28, 1999 6:35 PM
> To: EMAIL:PROTECTED
> Subject: RE: [UUG/MLUG] Various networking - extra
> 
> 
> A few weeks ago I ran a ton of wiring for a friend.  I went 
> to Home Depot to
> buy the RJ45 connectors.  The box I bought was a two piece 
> deal.  There was
> a really small guiding block that you put the pairs in first, 
> then you slip
> the guiding block into the connector itself.  This makes for 
> extremely easy
> crimps, and you will have only 1/4 inch of untwisted pair that Justin
> mentioned about.  More twist == cleaner signal  (:  Just 
> another two cents.
> 
> -mike
> 
> 
> 
> -----Original Message-----
> From: McNutt, Justin M.
> To: EMAIL:PROTECTED
> Sent: 11/28/99 2:00 PM
> 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
>