Hello everyone, in this video we're going to talk
about the different types of connectors that are used in networking and these connectors will vary
depending upon the type of network and the cable that they are attached to. Whether that cable is
twisted pair, coaxial, telephone, or fiber optic. And the first one we're going to talk about is
the RJ-45. Now the RJ-45 is by far the most common network connector. Now this is an eight pin
connector that's used to connect computers and other network devices in a local area network. The
RJ-45 is used with unshielded twisted pair cable. Twisted pair cable has eight wires and these wires
are arranged in a certain order and then the wires are inserted into an RJ-45 connector and then they
are crimped on both ends using a wire crimper. And then one connector would be plugged into the
computer's network card and then the other end would plug into a device, such as a switch, modem,
or a router. Then once that is done, the computer will be able to connect to a network. The RJ-45 has
a single locking tab that locks itself into place. Now this is a UTP coupler. Now this is not
really a connector. This is used for connecting UTP cables with RJ-45 connectors to each other.
This is typically used when running a longer cable is not an option. It's just used to extend a
network cable by joining two cables together using their RJ-45 connectors. So you would just plug one
end of the cable into the coupler and then you would plug in another cable on the other side. And
now you have successfully extended your UTP cable. And another type of connector that is similar
to the RJ-45 is the RJ-48. Now the RJ-48 looks very similar to the RJ45, but the difference between
the two is that the RJ-48 is used with shielded twisted pair cable instead of unshielded
twisted pair that's used with the RJ-45. The RJ-48 is primarily used with T1 lines and
it's also wired differently than the RJ-45. And this is the RJ-11 connector. This is a four
wire connector that's mainly used to connect telephone equipment. But as far as networking, the
RJ-11 is used to connect computers to a local area network through the computer's modem. The RJ-11
locks itself into place by a single locking tab and it resembles the RJ-45 but it's a little
bit smaller. The BNC connector is a type of RJ connector that is used with coaxial cable.
BNC stands for Bayonet Neill–Concelman. And the BNC is used with both analog and digital
video transmissions, as well as audio . Now these connectors are not very common anymore but they
can still be found on older networks. Now there are many different kinds of BNC connectors.
So or example here is a BNC-T connector which connects three coaxial cables together. And there
is also the BNC coupler, which is used to connect two coaxial cables together. And there is also
the BNC terminator, which is used to terminate the ends of a cable. Now this connector is called the
F-type. Now this is a threaded connector typically used on coaxial cables. These are primarily used
by cable providers to attach to cable modems. So if you have broadband cable like I do, you
will have a modem with a coaxial cable attached to an F-type connector that screws into the back
of your modem that attaches with a nut. And in addition to being used with broadband cable,
they are also used with satellite internet. And there is also the USB connector. The USB is
very common on desktops and laptops. And because 'universal' is in its name, it can be used for many
different purposes, including networking. So for example many manufacturers make USB wireless
adapters that plug into a USB port on a computer to give the computer wireless network access.
And there is also wired network adapters like this one here, where you would plug an ethernet
cable at one end and then the other end into a USB port on a computer and then the computer will
be able to access a network through its USB port. So now we're getting into fiber optic connectors.
Now fiber optic networks use pulses of light to send data. And there are many different types of
fiber optic connectors, but I'm only going to talk about the most popular fiber connectors. But the
main differences between these fiber connectors, are the size and the method they use when
coupling. So the first fiber optic connector is called the SC or standard connector. And this
is often called the square connector. And this was one of the first connectors to be used in the
marketplace. This uses a push pull connector, similar to audio and video plugs and these are
commonly used between floors in a building. This connector is called the MRTJ which stands for
mechanical transfer register jack. And this is a fiber optic connector that uses a latched push
pull connection. It has a small form factor that's used for high pack density and it was designed to
replace the SC connector. The MRTJ uses two fibers in a single design and it resembles the RJ-45.
This connector is becoming increasingly popular in fiber networks today. And our next fiber
connector is called the LC or local connector or Lucent connector, since it was developed
by Lucent. Now this type of connector is also commonly used between floors in a building and
it was designed to compete with the SC connector. It's about half the size of the SC connector
which makes it better for highly populated racks and panels and this also uses a latch that
locks itself into place similar to the RJ-45. And our last fiber optic connector is called the
ST or straight tip. Now this uses a half twist bayonet type of lock and is commonly used with
single mode fiber optic cable. Now this is a large size connector that was developed by AT&T.
And because of its large size, its usage has declined in favor of smaller connectors, such as
the LC and the MTRJ. Now just like UTP couplers, there are also fiber couplers. So if you
wanted to join two fiber optic connectors, you would use a fiber coupler. Now fiber couplers
are used to join or couple two of the same fiber optic connectors and the two connectors have to
be the same. Now these are not to be confused with fiber adapters, because fiber adapters
are used for joining two different connectors together. So here we have an example of a fiber
coupler joining two ST connectors together. So now we're going to talk about the difference
between UPC and APC end faces or tips on fiber optic connectors. And as examples we're going to
use a group of ST fiber connectors equipped with UPC and APC end faces. Now when fiber optic
connectors make a connection to each other, the point at which the connection is made is
not perfect, because of the small imperfections of the flat surfaces. So what happens is at
the point where the connectors join, light is transmitted from one connector to the other
connector. But at the point where light passes to the other connector, the light will reflect back
in the opposite direction towards the light source and when this happens, there is signal loss. And
this is what happens in UPC connectors. The light is reflected directly back. So as technology
progressed, a new connector was developed to decrease the signal loss. And this new connector
is called the APC connector. Now the difference between the UPC and the APC is the angle of the
end face or tip where the connection is made. So as I said before, with the UPC, the light reflects
back towards the light source. But with the APC, with its angled connection, the light doesn't
reflect back towards the light source, it reflects back at an angle into the wall of
the cable. And as a result, this greatly reduces the signal loss. So thank you everyone for
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