-: Wired WAN Connections. 2 2
In this lesson, we're going to talk about 3 3
Wired Wide-Area Network Connections. 4 4
So let's start out by talking about 5 5
the three main types of WAN connections 6 6
that you may find in enterprise or business networks. 7 7
These are dedicated leased lines, 8 8
circuit-switched connections 9 9
and packet-switched connections. 10 10
The first type we have is a dedicated leased line. 11 11
This is a logical connection 12 12
that's going to connect two of your remote sites together 13 13
through your internet service provider's facility 14 14
or a telephone company's central office. 15 15
This is a more expensive connection 16 16
than other WAN technologies because the customer 17 17
doesn't share the bandwidth with all the other customers. 18 18
Instead, they have full and dedicated use 19 19
of the entire connection. 20 20
If you have a direct copper cable, 21 21
something like a T1 connection going to your office, 22 22
this is an example of a dedicated leased line. 23 23
We're going to talk more about all the different types 24 24
of dedicated leased lines in our WAN technology videos. 25 25
But for right now, 26 26
I just want you to be introduced to this concept. 27 27
When you hear about a dedicated leased line, 28 28
I want you to think about it as 29 29
a single pipe going directly from 30 30
your service provider's office to your office, 31 31
and nobody can use it, but you. 32 32
Now, the second type we have 33 33
is known as a circuit-switched connection. 34 34
And this is a connection that works 35 35
by only being brought up when it's actually needed. 36 36
This type of data connection is similar 37 37
to making a phone call. 38 38
When you want to make a phone call, for example, 39 39
you dial the number and it connects you 40 40
with the other person that you want to talk to. 41 41
And then you can talk as much as you want 42 42
between each other, and when you're done, 43 43
you hang up the phone and the connection is torn down. 44 44
So if you talked for an hour, 45 45
you only use network connectivity for one hour of the day 46 46
and the other 23 hours of the day, 47 47
that connection could be used by other people 48 48
and resold by your internet service provider. 49 49
Now, in the old days of computer networks, 50 50
we actually had dial up internet 51 51
and internet connections that work like this. 52 52
So when we wanted to use those, 53 53
we would actually dial up and then use that connection 54 54
and hang up when we were done. 55 55
These connections, though, were extremely slow. 56 56
When you wanted that connection, it turned on, 57 57
it made the phone call, 58 58
You would then be able to go out 59 59
to the internet and do your business, 60 60
and when you're done, you'd hang up, 61 61
and that entire connection will be taken offline. 62 62
This on-demand bandwidth did provide cost savings 63 63
because you're not using 24/7 access. 64 64
Instead, you're only getting it when you need it, 65 65
and so it makes for a cheaper connection. 66 66
All the other time that you're not using it, 67 67
your telephone company or your ISP 68 68
can actually sell that service to somebody else, 69 69
and therefore you're doing 70 70
cost sharing across multiple customers. 71 71
Now because the dial up version of this was so slow, 72 72
there was something introduced called ISDN, 73 73
which is a digital circuit-switched technology. 74 74
Now ISDN stands for the Integrated Service 75 75
Digital Network Connection. 76 76
And a lot of businesses use these 77 77
instead of using a dedicated leased line, 78 78
because they were much, much cheaper. 79 79
Again, we're going to talk about ISDN 80 80
in our WAN technologies lesson, but for now, 81 81
just to equate this type of WAN connection 82 82
by making a phone call, but we're using 83 83
data instead of using our voice. 84 84
These circuit-switched technologies 85 85
will give you full access to the bandwidth when you need it, 86 86
but when you're not using it, 87 87
it takes it back and uses that same capacity 88 88
to provide service to other customers. 89 89
For this reason, circuit-switched technologies 90 90
are more efficient from a service provider perspective 91 91
and therefore a cheaper option to obtain 92 92
for an end-user like your business or mine, 93 93
than using a dedicated leased line. 94 94
The third type of connection we have 95 95
is known as a packet-switched connection. 96 96
Now a packet-switched connection works 97 97
like an always on dedicated leased line. 98 98
But the difference here is that 99 99
multiple customers are sharing that bandwidth. 100 100
This allows it to be a cheaper line for us to buy, 101 101
and for our customers to use. 102 102
Each customer is given an SLA or service level agreement 103 103
with the internet service provider. 104 104
And this is going to dictate the level of service 105 105
they can expect to get based on the money they paid. 106 106
For example, in this SLA contract, 107 107
you might be guaranteed a certain level of quality or speed 108 108
that you require for your business's use case. 109 109
You might purchase an SLA that guarantees you 110 110
at least five megabits per second, 111 111
at least 95% of the time, as an example. 112 112
Now, these packet-switched connections 113 113
are built as virtual circuits, 114 114
not dedicated connections like a T1. 115 115
Since they're virtual circuits, 116 116
they're going to be represented as dash lines 117 117
when you see them on a network diagram. 118 118
The most well-known example of a packet-switched connection 119 119
is what's known as a frame relay connection. 120 120
Again, we're going to talk more about 121 121
frame relay, specifically, in our WAN technology videos. 122 122
But for right now, I just wanted to 123 123
introduce the concept of a packet-switched connection, 124 124
being a virtual network, 125 125
instead of using a dedicated circuit. 126 126
And this way we are going to have 127 127
it supported by a contractual agreement, 128 128
with a service level agreement, 129 129
instead of having all the dedicated bandwidth all the time, 130 130
so therefore we can save some money. 131 131
All right, now that we've covered 132 132
our three types of WAN connections 133 133
of dedicated leased lines, circuit-switched connections, 134 134
and packet-switched connections, 135 135
we need to discuss what the WAN connection 136 136
physically looks like. 137 137
This physical connection is going to be 138 138
using some sort of physical network media 139 139
in order to make that WAN connection. 140 140
And then we have to connect it to our gateway, 141 141
which is normally our router. 142 142
After all, this is how the ones and zeros 143 143
are going to get into and out of our network 144 144
and go across that WAN connection. 145 145
Now, there are lots of different types 146 146
of physical media used, including copper wires, 147 147
fiber optic cables, power lines and wireless, 148 148
which can contain numerous different types 149 149
of wireless methods for WAN connections. 150 150
Because there's a lot of different 151 151
wireless methods out there, 152 152
I'm going to cover those in a separate video, 153 153
but for now, let's take a quick look 154 154
at the different types of wired WAN connections. 155 155
First, we have copper wires, 156 156
and these may take the form of an unshielded twisted pair, 157 157
UTP, shielded twisted pair, STP, 158 158
or coaxial cable known as Coax. 159 159
Now, when we use UTP or STP, 160 160
it's just like the cables we use 161 161
internally on our local area networks. 162 162
We're going to use something like cat five, 163 163
cat six, or cat seven cable. 164 164
When we use coaxial cable, 165 165
it's going to allow us to cover more distance 166 166
than a standard UTP or STP cable. 167 167
Other than that, there's not really 168 168
a big difference between using any of these 169 169
three types of copper cables, UTP, STP or Coax. 170 170
Now all three of these different copper cables 171 171
can support both analog or digital connections. 172 172
Some types of WAN connections are going to 173 173
rely on UTP or STP copper cables. 174 174
This might be things like dial up connections, 175 175
ISDN connections, E1 or T1 connections. 176 176
And if you're using coaxial connections, 177 177
this is usually going to be used with cable modems. 178 178
And this is going to come from a cable service provider 179 179
for your or business internet service. 180 180
Our second type of media we have is fiber optic cables. 181 181
These cables support very high bandwidth 182 182
and long distance connections. 183 183
Also fiber connections are also not subject 184 184
to electromagnetic interference like copper connections are. 185 185
So they're usually very stable 186 186
when you're using them as a network connection. 187 187
Unfortunately, though, these connections 188 188
are more expensive than using a copper cable. 189 189
If you're going to have a direct fiber connection 190 190
to your home or office, this could cost you a lot of money. 191 191
Thankfully prices are continuing to drop, though, 192 192
especially in the small office, home office market. 193 193
Here in the United States, for example, 194 194
you can get a Verizon Fios connection, 195 195
which is a fiber optic connection, 196 196
all the way to your house, 197 197
that can support speeds of up to one gigabit per second, 198 198
for under about a hundred dollars per month. 199 199
As the price keeps going down for fiber optic connections, 200 200
you're going to see more and more people using them. 201 201
Our third type of media that we have is power lines. 202 202
Yeah, I know this sounds a little weird, 203 203
but those power lines that give you power 204 204
and electricity to your house, 205 205
they actually can provide internet service 206 206
to your home as well, 207 207
using something known as BPL or broadband over power lines. 208 208
BPL connections can support 209 209
a speed up to 2.7 megabits per second, 210 210
which by today's standards seems pretty slow, 211 211
but it actually is about the same speed 212 212
as a slower DSL or digital subscriber line connection. 213 213
Basically broadband over power lines 214 214
was introduced because everywhere in America, 215 215
including rural portions, 216 216
already have power lines running 217 217
to their homes, for the most part. 218 218
Many of these rural areas though, 219 219
didn't have phone lines or cable TV lines or fiber optics. 220 220
So there was no easy way to get internet to them, 221 221
but with broadband over power lines, 222 222
there's already a usable infrastructure 223 223
of power lines in place. 224 224
So we could run the internet over that 225 225
as a great stop gap measure until better solutions 226 226
could be run to those places. 227 227
Over time, you're going to see 228 228
broadband over power lines retired, 229 229
since more and more areas of the country 230 230
are getting wired for coaxial or fiber cables 231 231
directly to people's home, 232 232
and satellite internet is increasing. 233 233
Now here in the United States, 234 234
broadband over power lines is not very popular, 235 235
but in some countries, 236 236
this can be a fast and easy way 237 237
to get internet out to end users 238 238
because power lines already exist, 239 239
and so the infrastructure is already there. 240 240
Now, all right, I know that was a lot of different 241 241
wired WAN types that we covered in this video, 242 242
including copper fiber and power lines. 243 243
Remember, you need to be able to consider 244 244
each of these when you're trying to determine 245 245
what the best wired WAN connection might be 246 246
for a given scenario or use case 247 247
when you're in the field as a network technician, 248 248
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