If you're going to be working on networks,
then you're going to need a good set of crimpers.
This will allow you to fasten the RJ45 connector
to the end of the wire.
Some crimpers also provide other connections
so you can crimp RJ11 or coax connections
on this same crimping device.
This is really useful if you're running your own cable.
You can cut cable exactly to the length you need,
and then put your own connectors onto the end of those cables.
The crimper is pushing these sharp metal prongs
that are on the inside of the RJ45 connector
into the insulation that's around each individual wire.
The crimper is also pushing a connection
in on the back of the RJ45 connector that
fastens it securely to the outside of the cable sheath.
Here's a good picture of these RJ45 modular connectors
before they're crimped.
You can see they're sticking out just a little bit
with these copper connectors.
And look at those sharp metal pieces
that are on the end of the connector.
That's what's going to push into the insulation that's
around each individual wire.
If we push our wires into the crimper
and then crimp down and push those copper connections in,
you should have a crimp that looks something like this.
All of the cables are through the entire part
of the connector, and you can see that those sharp metal
pieces have now been pushed into the individual wires, all
the way through these eight different connections
on the RJ45 connector.
You also notice on the back of the connector
is a cable stay that has also been pushed into hold
this entire cable in place.
Once you start doing a lot of cable crimping,
you'll know that you'll need to get not just
a very good quality crimper, but you'll also
need some electrician's scissors.
These might be called cable snaps.
They're perfectly sized to be able to work
on these very small cables.
You might also want a good wire stripper, especially
if you work with a lot of coax.
A number of crimpers will also include a wire stripper
on the crimper itself.
Also make sure that you're using the appropriate type
of modular connectors for the type of cable that you have.
The type of connectors that go on a category 5
are just a little bit different than those
that go on a category 6 cable, so make sure
you match your connectors with your cables.
And although this can be a little frustrating at first,
you very quickly can get the feel
for pulling out all of these individual wires,
putting them onto the connector, and crimping them down
into the perfect sized cable.
Now that you performed this crimp,
how do you know that the crimp is actually working?
One way to tell is to put a cable tester on the wire.
This is performing a continuity test across the wire,
so you can very quickly see if pin 1 is
connecting to pin 1, if pin 2 is connecting to pin 2, and so on.
If something did go wrong, this cable tester
can also tell you if pin 3 isn't connecting to anything
on the other side, or if any wires may have been crossed
between any of the pins.
These cable testers are relatively simple devices.
These usually have just about eight lights on them.
This one also has a ground light.
And it will tell you if the light turns
on then you have continuity, and if the light doesn't turn on,
something's gone wrong with your crimping.
If you need more advanced analysis of the cable,
like crosstalk information or signal loss across the wire,
then you'll probably want to bring in a TDR, or a Time
Domain Reflectometer.
If you're working with copper cables, it's a TDR.
If you're working with fiber, then it's
an Optical Time Domain Reflectometer, or OTDR.
These will be able to provide you with a lot of information
about your copper cable or your fiber.
For example, you can plug it into a connection,
and it will estimate the entire length of the cable.
Even if the cable's going into the ceiling
and you're not able to see exactly how long it is,
connecting the TDR will give you a very accurate representation
of the length.
If your cable has a cut or splice,
you can plug in the TDR, and it will tell you
exactly how far down the cable that particular problem exists.
If you're simply trying to understand what type of cable
it is, you want to understand the impedance on the cable,
you can plug in the TDR and it will tell you
that information as well.
We commonly use these TDRs and the OTDRs
when we're first installing a cable infrastructure,
because you can plug these devices in and see just how
much signal we're losing between one side
of the cable and the other.
This is especially good for fiber,
where you want to be sure over very long distances
that you're minimizing the amount
of light loss over that run.
These TDRs often work with software
that allows you to log every single connection that you're
testing, so at the end you can create
a report that verifies that everything on the network
is working as expected.
Or if you're concerned that there's a cut in your fiber
or copper, you can plug in a TDR and know exactly how far down
that run you have the break.
The TDR is able to determine where these breaks are
because it's sending a ping of information down that wire,
and it's listening for any reflections that are
coming back from any problems.
The TDR will then calculate the time
that it took to send that signal from the time
that it heard the reflection and tell you what the distance is
between those two.
The OTDR does exactly the same thing,
except it's doing it with light.
It sends the light down the fiber,
and then it watches for any reflection to come back.
Visually, we can see this happen as we send signals
down the wire.
Runs into a problem, and a little bit of that signal
is reflected back to the TDR.
See that again.
We send the signal.
Some of that signal is going to make its way
down the rest of the wire, but wherever we have that problem
is where we're going to see the reflection come back
to the TDR.
A TDR or an OTDR can be an expensive investment.
These are thousands of dollars to have
a piece of equipment that's able to perform
these particular functions.
And you're probably going to need additional training so
that you know how to operate the equipment
and understand the results that it's providing.
But if you need some way to certify
that your cables and your fibers are working as expected,
this would be exactly the tool that you would use.
You can validate everything about your installation
and certify that all of your network connections
will be working exactly to spec.
If you're working a lot with patch panels,
then you'll probably be using a punch-down tool.
This is the device that's going to push
the cable into those sharp connections
on the punch-down block and be able to lock
those wires in place.
You would use this with a 66 block
or a 110 block most commonly on today's networks.
This can be very tedious to do, because you
have to put every individual wire into each connection
on the punch-down block, and then manually punch down
every single one of those.
While you're punching this wire into the block,
you would not only push the wire into the block,
but also trim off any excess and keep that out of the way.
So as long as you have all of your wires lined up,
you can very quickly punch down all eight connections
for a single ethernet drop.
When you're working with patch panels and punch-down tools,
you want to make sure that you've
got everything organized.
You're going to have a lot of wires in one very small space.
This patch panel helps by numbering
each one of these connectors and showing you
exactly where the wires go while you're punching them down.
On today's high speed ethernet networks,
you also want to be sure to keep these twists in the wire--
just as it shows here--
as close as possible to where it's going
into the punch-down block.
And once you're done connecting these patch panels,
you usually want to document exactly
which one of these interfaces is connecting with which desk
that's out on the floor.
If you're running your own cable and crimping RJ45 connections,
it's very common to use a cable tester
to make sure there's continuity for all eight of those pins.
If you're running fiber connections,
you may want to perform similar tests on the fiber.
But on fiber, we're not checking for continuity.
For fiber, we want to see just how
much light is making its way from one
side of the fiber to the other.
In those cases, we use a light meter
that will be able to tell us exactly how much of our signal
is making it through that fiber run.
These light meters will send the light from one side.
This may be a laser or an LED, depending
on the light meter and the type of fiber that we're using.
And then we'll have a device that's
going to measure how much of that light
we're able to receive on the other side.
If you have a very long fiber run
and you're concerned that your equipment may not
be able to see all of the light coming through,
it's useful to use a light meter to be
able to see exactly what the results will
be once you connect your production equipment.
If you've been working with a patch panel
or with a large number of wires that's coming into a room,
and you're trying to determine where
the other end of a particular wire is,
then you'll want to use a tone generator.
This tone generator will put an analog sound on the wire,
and then we use a separate inductive
probe to find out where the other end of the wire
happens to be.
We don't have to break the wire open or touch any copper.
This inductive probe allows us to do this
without changing anything with the wire.
This makes it very easy to find an individual wire, even when
you're in a data center where there
are hundreds of cables coming in to a single connection.
You would first connect this tone generator to the wire.
These usually have modular jacks and coax connections
that can fit on to almost any type of cable.
And then you go to the other end and start
using the probe to try to find the wire that's connected
to this tone generator.
Here's my tone generator.
It's a very inexpensive one.
I don't use it a lot, but it does come in handy.
This has the tone generator here,
and then it has an inductive probe that comes with it.
I have connectors on the back.
I can open it up.
It has a lot of different options
for plugging into a number of different types of network
connections.
Here are some wires that are running
across the floor of the studio.
I plugged my tone generator into the end of the other wire.
Now I'm trying to find out which one of these
is connected to that tone generator.
Now I can take my inductive probe.
There's a button on the front that I simply push.
And now it's listening.
I simply need to only touch it to the outside of the wire.
Not hearing anything on that wire,
I'm not hearing anything on this wire,
and you can see when I touch the middle wire,
I can hear the tone that's being created by the tone generator.
If you're trying to perform some troubleshooting on a network
connection, you may be required to loop the signal coming out
of that device back into the device that it came from.
This is so it can perform some tests sending
some signals to see exactly what type of signals it's receiving.
The way we would this back is with a loopback plug.
This allows us to test WAN connections,
ethernet connections, and anything else that
needs to send traffic out and loop it back to itself.
It's common to see loopback plugs used
with serial connections or WAN connections.
These could be RS-232 either 9 pin or 25 pin.
They might be network connections for ethernet, maybe
a T1 connection.
There's even fiber loopbacks that you
can use with fiber connections.
It's important to note that this is not a crossover cable.
Crossover cables connect like devices to each other.
The loopback plug only has one single plug on it.
You can see the wires come out of the plug
and then back in to loop the signal back to itself.
Multimeters are tools that any one
should have in their tool bag.
They of course allow you to test the AC voltage
so you can see if you are getting power
from a power outlet.
They also have options to be able to look at DC voltage
as well, so you can check the voltage
that's inside of the network devices that you're using.
You also have continuity tests on here.
And for networking, you can use those continuity tests
to see if you're getting connections between one
end of a cable and another.
If you don't have a cable tester,
for example, you can use this multimeter
to provide that continuity check against each pin of the cable,
and build your own wire map using the multimeter.
Another nice tool to have, especially
for wireless networks, is a spectrum analyzer.
This allows you to examine all of the different frequencies
that happen to be in a particular range all at once,
and you'll be able to tell exactly
where most of the signal is in that particular frequency
range.
For example, if you're connecting a wireless access
point for the first time, and you're
wondering if there's anything else in the area that
might be causing interference to slow down this network,
you'll be able to see that with the spectrum analyzer.
It views everything across a particular set of frequencies.
So if the problem is a conflict with another wireless access
point, you'll be able to see that in the spectrum analyzer.
And if there are other devices in your environment
that are causing interference on those same frequencies,
it will also show up with the spectrum analyzer.