-: Cabling tools. 2 2
In this lesson, we're going to discuss the various tools we use 3 3
when working at the physical layer of our networks, 4 4
especially with copper and fiber cabling. 5 5
This includes snips and cutters, cable strippers, 6 6
cable crimpers, cable testers, 7 7
wire maps, cable certifiers, multimeters, 8 8
punch down tools, tone generators, 9 9
loopback adapters, time-domain reflectometers, 10 10
optical time-domain reflectometers, 11 11
fiber light meters, fusion splicers, 12 12
taps and a spectrum analyzer. 13 13
Woo, lots of stuff we're going to cover. 14 14
All right, the first cabling tool we have 15 15
is probably the most basic one that we're going to cover 16 16
and it's a snip or a cutter. 17 17
A snipper or a cutter is used 18 18
to simply cut a piece of cable off of a larger spool 19 19
or run of cable. 20 20
Now, a snip looks a lot like a pair of scissors, 21 21
but it has stronger blades because we're going to use it 22 22
to cut off twisted pair of copper cables, 23 23
coaxial cables or even larger cable bundles. 24 24
Next, we have cable strippers. 25 25
Now, once we cut the piece of cabling off the larger spool 26 26
using our snips, we now need to strip off the end 27 27
of the cable and prepare it for attachment 28 28
to a plastic RJ45 connector 29 29
or whatever kind of connector we're going to use. 30 30
For example, let's say I wanted to create a crossover cable. 31 31
I'm going to cut off some twisted copper from the spool, 32 32
then I'm going to strip both ends using a cable stripper. 33 33
This allows me to remove around six to 12 inches 34 34
from the outer plastic jacket at the end of the cable 35 35
and then I can spread out those inner wires, 36 36
prepare to attach the RJ45 connector to them 37 37
and then I'm going to have to use a crimper to do that. 38 38
Now, if I'm making a coaxial cable, 39 39
I would then use a coaxial specific wire stripper 40 40
to remove the outer jacket of the cable 41 41
and the insulation, so I can now get to that center conduit 42 42
for that RG6 connector to go through 43 43
and be put on the end of that cable. 44 44
Next, we're going to use a cable crimper 45 45
and this is how we attach the connector 46 46
to the end of the cable. 47 47
Again, let's say I'm making that crossover cable. 48 48
I need to use an RJ45 connector 49 49
and RJ45 specific cable crimper. 50 50
Normally your cable crimper is going to be used 51 51
for twisted pair cabling 52 52
and it's going to support both RJ45 and RJ11 connectors. 53 53
If you're working with coaxial cables, 54 54
there's a different cable crimper you'll use 55 55
that'll support RJ6 or RG59 connectors. 56 56
All right, now that we've created our cable 57 57
using our snips and cutters, our cable stripper 58 58
and our cable crimper, we need to test the cable 59 59
and this is where we use a cable tester. 60 60
A cable tester is going to be used to verify the continuity 61 61
of each of the eight individual wires 62 62
inside of that twisted pair of cable. 63 63
This will verify there's no breaks inside the cable 64 64
and that we have good continuity from one end to the other. 65 65
By using a cable tester, 66 66
we can verify the pin outs were done properly 67 67
and that each individual wire in the twisted pair of cable 68 68
is properly connected for a straight-through 69 69
or crossover cable, whichever one we were making. 70 70
Now, there are different types of testers 71 71
for different types of cable. 72 72
If you're testing an ethernet cable, 73 73
you're going to need one with an RJ45 connector 74 74
on the cable and that cable tester. 75 75
Now, if you work with a lot of different types 76 76
of networks though, you may want to use a multi tester. 77 77
A multi-tasker isn't going to support 78 78
just ethernet cables using RJ45, 79 79
but it can also support BNC connectors for coaxial cables, 80 80
IDE connectors for hard drives, pata and sata connectors 81 81
for internal computer devices, RJ45, 82 82
again for your ethernet, RJ11 for your telephones, 83 83
fiber, DB25, DB9s and anything else you might need to test. 84 84
Next, we have a wire mapping tool. 85 85
Now a wire map tool is like a cable tester, 86 86
but it works specifically for twisted pair ethernet cables. 87 87
In addition to testing the cable from end-to-end, 88 88
we can diagnose any issues with that cable, 89 89
such as an open pair, a shorted pair, 90 90
a short between the pairs, a reverse pair, 91 91
a cross pair or a split pair. 92 92
Now, an open pair occurs when one or more conductors 93 93
in the pair are not connected on one of the pins 94 94
at either end of the cable. 95 95
In other words, the electrical continuity 96 96
of the conductor is being interrupted. 97 97
This can occur if the conductor 98 98
has been physically broken somewhere in the middle 99 99
or because you had an incomplete or improper punch down 100 100
on a patch panel. 101 101
Now, a short can occur when conductors of a wire pair 102 102
are connected to each other 103 103
at any location within the cable. 104 104
A short between the pairs occurs 105 105
when the conductors of two wires in different pairs 106 106
are connected at any location within the cable. 107 107
A reverse pair occurs when two wires in a single pair 108 108
are connected to the opposite pins of that pair 109 109
on the other end of the cable 110 110
and cross pairs occur when both wires of one color pair 111 111
are connected to the pins of a different color pair 112 112
on the opposite end. 113 113
Split pairs occur when a wire from one pair 114 114
is split away from the other 115 115
and crosses over the wire into an adjacent pair. 116 116
Because this type of fault 117 117
essentially requires the same mistake to be made 118 118
at both ends of the cable, 119 119
it usually doesn't happen very often 120 120
unless somebody meant to do it. 121 121
Next, we have a cable certifier. 122 122
Now, a cable certifier is used 123 123
with an existing cable to determine its category 124 124
or data throughput. 125 125
I can plug into your network and find out, 126 126
is it a CAT5, CAT6, CAT5e, CAT7 or CAT8 network. 127 127
It's going to tell me 128 128
based on the frequency range being used, 129 129
what the throughput of the cables are 130 130
and the standard output is shown here on the screen, 131 131
as you can see. 132 132
Now, notice I have a wire mapping here 133 133
that shows my pins are correct, 134 134
that it's a straight-through cable. 135 135
It's also going to tell me how long this cable is. 136 136
In this case, it knows it's 10 feet. 137 137
Then it's going to tell me what the delay is on the cable. 138 138
It tells me what the resistance is on the cable. 139 139
All that type of good information can be gotten 140 140
from a cable certifier. 141 141
Essentially, it can do a lot of the same functions 142 142
as a cable tester, but it goes further 143 143
and gives you additional details 144 144
such as length and throughput. 145 145
So I can use this to determine the length 146 146
and make sure it's right for a particular cable 147 147
or if the cable has been crimped properly, 148 148
just like a cable tester does, 149 149
but all this other information is really good too. 150 150
Now, because of all this extra information, 151 151
these devices are more expensive. 152 152
When you're dealing with a simple cable tester, 153 153
you can buy that for about $10, 154 154
but a cable certifier might cost you 100 or 200 or $300. 155 155
Next, we have a multimeter. 156 156
A multimeter is a way to check the voltage 157 157
or amperage or the resistance of a copper cable. 158 158
This can used to verify if a cable is broken or not 159 159
by checking its resistance. 160 160
Now, if I check a copper cable from end-to-end, 161 161
I should get something at zero resistance or zero ohms, 162 162
because the center of that wire is pure copper. 163 163
Now, if there's a high level of resistance or an overload, 164 164
that means there's a break in the cable somewhere. 165 165
Now, multimeters can be used to check coaxial cables as well 166 166
to ensure there's no cuts or breaks 167 167
in the middle of a patch run 168 168
or it can be used to test power sources and power cords. 169 169
For example, before I plug a computer 170 170
or a switch or a router into an outlet, 171 171
I might want to check that outlet 172 172
and verify I'm getting the right voltage. 173 173
Is it getting 115 to 125 volts here in America? 174 174
That would be right. 175 175
If I'm in Europe, I should be getting 230 to 240 volts. 176 176
Either way, I can test that using my multimeter 177 177
and make sure I'm getting good, clean, reliable power 178 178
before I connect my very expensive switches, 179 179
routers and other gear into those power outlets. 180 180
Next, we have a punch down block. 181 181
If I'm going to be using a 66 block or a 110 block 182 182
for either my phones or my networks 183 183
or even my network jacks in the wall, 184 184
I'm going to be using punch down tools to install those cables. 185 185
This is going to terminate the wire on the punch down block 186 186
and strip off the excess installation 187 187
and trimming off all the extra wires that we no longer need. 188 188
Next, we have a tone generator, also known as a toner probe. 189 189
Now, a tone generator allows a technician 190 190
to generate a tone on one end of the connection 191 191
and use the probe to audibly detect 192 192
the wire connected on the other side. 193 193
This is often called a fox and hound, 194 194
because the fox generates the tone 195 195
and then the hound is used to sniff it out 196 196
and find it using that toner probe. 197 197
A tone generator is going to be used to understand 198 198
where the cables are running inside of your walls 199 199
whenever you have an unlabeled or undocumented network 200 200
and you need to figure out which wire 201 201
is connected to which jack inside your building. 202 202
Next, we have a loopback adapter or loopback device. 203 203
These loopback adapters are going to be different 204 204
depending on whether or not you're using ethernet 205 205
or fiber in your networks. 206 206
Now, if you're using twisted pair cabling in your networks, 207 207
you can create your own inexpensive loopback adapter 208 208
by simply connecting some of the twisted pair of wires 209 209
from the transmit side to the receive pins 210 210
inside the same RJ45 connector. 211 211
Essentially, you need to have your transmit plus 212 212
going to your receive plus, 213 213
which means pin one goes to pin three, 214 214
then you need transmit minus going to receive minus. 215 215
This is pin two going to pin six. 216 216
If you're using fiber in your networks, 217 217
you can simply connect your transmit port 218 218
to your receive port using a fiber patch cable 219 219
and this creates a loopback for you. 220 220
This is extremely easy to do 221 221
if you're using an ST or SC connection 222 222
and they do make specialized loopback plugs 223 223
in a small form factor, 224 224
so you can carry these in your pocket 225 225
when you're working as a network technician. 226 226
Now, once you connect your loopback adapter to your network, 227 227
you can then use specialized diagnostic software 228 228
to test the connectivity of the client 229 229
and ensure everything's working properly. 230 230
Next, we have a TDR, 231 231
which is known as a time-domain reflectometer. 232 232
Now, a time-domain reflectometer 233 233
is going to locate breaks in a copper cable 234 234
and provide an estimate of the severity 235 235
and the distance to that break. 236 236
If I have cable running underground between two buildings 237 237
and I need to figure out where it's broken, 238 238
because my network stopped working 239 239
and I need to dig a hole and fix that, 240 240
I can use a TDR to look at exactly where that break is. 241 241
When the TDR is run, it's going to report back 242 242
that there's a break at approximately 87 feet away 243 243
and now I know exactly where to dig, 244 244
being able to access that cable and then patch that cable. 245 245
Now there's also an optical version of this, 246 246
called an optical time-domain reflectometer or OTDR. 247 247
This is going to be used for fiber optic cables. 248 248
It works the same way, 249 249
but instead of using the resistance of the wire, 250 250
we're using light and the bounce back for it. 251 251
This is really helpful, especially with fiber optic cables, 252 252
because remember, your fiber optic cables 253 253
can be many, many miles long 254 254
and so knowing that the break is at 3.57 miles away 255 255
is a lot more useful than trying to figure out 256 256
where it is on your own. 257 257
This is going to be essential 258 258
if you're using fiber underground, 259 259
then you want to make sure you have an OTDR, 260 260
because you won't be able to visually inspect 261 261
your fiber if it's buried. 262 262
Next, we have a fiber light meter, 263 263
also known as an optical power meter. 264 264
Now, a fiber light meter is a device 265 265
that provides a continuous wave of stable source of energy 266 266
for attenuation measurements. 267 267
Essentially, this device is going to include a source, 268 268
like a laser or an LED and it's going to be stabilized 269 269
using an automatic gain control mechanism, 270 270
so we can accurately measure how effective 271 271
a fiber optic cable is transmitting that light. 272 272
If you're using multimode fibers, 273 273
you're going to use an LED-based fiber light meter. 274 274
If you're using single mode fibers, 275 275
you need to use a laser-based fiber light meter. 276 276
Basically, you're going to connect one part 277 277
of the fiber light meter 278 278
to each end of the fiber connection. 279 279
One end is going to send light down the fiber, 280 280
the other end is going to measure how much is being received. 281 281
Then it's going to report back to you in decibels, 282 282
the amount of loss experienced 283 283
as the light traveled along the cable. 284 284
If the loss is higher than 0.5 decibels, 285 285
both ends of the fiber should be cleaned, 286 286
polished and retested once more. 287 287
Next, we have fusion splicers. 288 288
Now, a fusion splicer is a machine 289 289
that's used to permanently join two fibers together. 290 290
If you have a break in a fiber cable, 291 291
a fusion splicer is going to be used to cut out that break 292 292
and then reconnect or splice them back together again. 293 293
If you're dealing with a fiber patch cable, 294 294
I wouldn't bother using a fusion splicer. 295 295
Instead, you're just going to replace the cable, 296 296
but if you have a really long fiber cable 297 297
running between two buildings or across the city, 298 298
that is a time where it's going to be a lot cheaper 299 299
to fix that broken fiber by using a fusion splicer 300 300
than it would be to dig up 301 301
and replace the entire cable again. 302 302
Fusion splicers are going to require training 303 303
to properly use them and it's a very specialized skillset 304 304
and a job for a network technician 305 305
who works a lot with fiber networks. 306 306
I'll tell you personally, I've never used a fusion splicer. 307 307
I've hired people when I had that need. 308 308
Next, we have a tap. 309 309
A tap is a simple device that connects directly 310 310
to the cable infrastructure 311 311
and splits or copies those packets for use in analysis, 312 312
security or general network management. 313 313
You're going to need to purchase 314 314
and install the appropriate tap for your type of network, 315 315
depending on if you're using copper or fiber. 316 316
Now, basically you're going to connect the tap inline 317 317
to your network and it's going to create a duplicate copy 318 318
of every frame, one going out the tap port, 319 319
where it's going to be collected 320 320
and analyzed by your cybersecurity tool set 321 321
and the other one out to your network, 322 322
so it can be processed by the equipment. 323 323
This is used heavily in cybersecurity, 324 324
but it can also be used in network management 325 325
and network operations. 326 326
Finally, we have a spectrum analyzer, 327 327
a spectrum analyzer is a device that measures 328 328
and displays the signal amplitude 329 329
or the strength as it varies by frequency 330 330
within its frequency range known as the spectrum. 331 331
Now, the frequency is going to appear on the X-axis 332 332
or the horizontal access 333 333
and the amplitude is going to be displayed on the Y-axis 334 334
or the vertical axis. 335 335
A spectrum analyzer is going to be used 336 336
to measure the electrical signals 337 337
that are being passed over that medium. 338 338
Now, the medium could be a copper cable, 339 339
such as ethernet or coaxial 340 340
or it could be a radio frequency 341 341
if you're listening to a particular radio wave. 342 342
If you're working with a satellite connection, for instance, 343 343
you might use a spectrum analyzer to ensure your modem 344 344
and radio are properly sending 345 345
and receiving the carrier waves to and from that satellite. 346 346
Again, this is a more specialized tool 347 347
that most entry-level network technicians 348 348
are not going to find themselves operating. 349 349
All right, I know that was a lot of different tools 350 350
that we just covered. 351 351
Remember, when you're dealing with the physical layer 352 352
of your network, especially if you're dealing 353 353
with copper or fiber cabling, 354 354
you're going to be using a lot of different tools 355 355
for a lot of different things. 356 356
This includes things like snips and cutters, 357 357
cable strippers, cable crimpers, cable testers, 358 358
wire maps, cable certifiers, multimeters, 359 359
punch down tools, tone generators, loopback adapters, 360 360
time-domain reflectometers, 361 361
optical timed-domain reflectometers, fiber light meters, 362 362
fusion splicers, taps and spectrum analyzers. 363 363
For the exam, it's important for you to understand 364 364
which tool you might use to troubleshoot 365 365
which type of cable and which type of issue.