Installing Networks - CompTIA Network+ N10-009 - 2.4

A distribution frame is an area
of the network where you are

passively terminating cables.

This usually involves
punch down blocks,

like the ones we see here.

Could be patch panels
or any other method

where we are terminating
those cables, usually

in a data center or some
other large facility.

You will usually find
this distribution frame

on the back wall
of the data center,

and it's often
terminating cables

that are coming in for your
local area network and voice

communication.

And although the punch down
blocks and patch panels

that we have on the wall are
technically the distribution

frame, we often refer
to the entire room

as the distribution frame room.

For example, the primary
distribution frame

is called the Main
Distribution Frame or MDF,

and we often refer
to the entire room

where it's located
as the MDF facility.

The MDF is usually
a single room.

It's often the data center or
central point of the network.

And this is where we might bring
in wide area network connections

and punch those down, along with
all of our internal local area

connections as well.

Since we have all of this
connectivity in one place,

it is a perfect testing
point, especially

if you need to test both
your internal local networks

and your external wide
area network connections.

And even if your network doesn't
have this large set of punch

down blocks in the
back, we sometimes

even often refer to this central
data center room as the MDF.

Here's a view of one MDF.

This one contains a
number of different racks,

with computer equipment and the
networking components as well.

Here's another MDF.

You can see a large
number of punch

down blocks or patch panels that
are on the single rack and some

on individual racks as well.

And it's intermixed
with the equipment

that we need to run inside
of this data center.

Another type of
distribution frame

is the Intermediate
Distribution Frame or the IDF.

Usually, the IDF is in a separate
floor or a separate building,

and it's often directly
connected to the MDF.

Most IDFs these days
include switches, routers,

and other equipment
that you need

to be able to connect
this area of the network

to the larger MDF.

You usually find this combination
of MDFs and IDFs in medium

to larger scale
environments, where

you need to have many
different remote rooms

all connecting back to
the central data center.

Here's a view of what
that would look like,

where you have the MDF.

Maybe this is where our
internet connection comes in.

There might be a core
router and a core switch.

You might even have file servers
and database servers in the MDF.

Maybe on different
floors of the building,

you would then have
individual IDFs.

In this case, there are two.

But there might
be more than that

in this particular environment.

And in the IDF, you might be
connecting users on the floor

to a central switch in the IDF.

And that switch
is connecting back

to the main core
switch in the MDF.

We've already seen an
example of an IDF and an MDF.

And one of the things
that you'll notice

is there are racks that
are very common in each

of those environments.

That's because the racks that
we use in these environments are

standardized and most rack
sizes are 19-inch racks.

They're 19 inches
across in each of these.

And we design our equipment to
fit perfectly into that 19-inch

width.

You'll also notice that the
equipment in these racks

might also have
different heights.

And we have a standard for those
heights known as a rack unit

or a U. 1U would be 1.75 inches.

And we can measure a
different number of units

based on that value.

So you can easily tell somebody
that we need 2U or 3U of space

to be able to install
a piece of equipment.

And most racks, like
the ones we see here,

are generally about
42U in height.

Although the width
is standardized,

the depth of these
racks can often vary.

There might be racks
that are very shallow

or others that might support a
much longer piece of equipment

that you would install.

Fortunately, most devices
follow the standardized form.

We know that if we're receiving
a piece of equipment that

is rack mountable, that it will
most likely be 19 inches wide.

We'll just need to
make sure that we

have a rack that is deep enough
to handle that particular piece

of equipment.

Since we have these
standard widths,

we can start stacking
this equipment

and using every
bit of real estate

that we might have available.

For example, this system
administrator has installed

a server that's
about 3U in height.

And they're installing
another set just above it

so that they can stack them
one right on top of the other.

Now that we have all of this
equipment in the data center

and it's all running
constantly, it's

creating quite a bit of heat.

We need to make sure
that we have a way

to cool this data center so
that all of this equipment

continues to work optimally.

We would do this by implementing
an H-V-A-C or HVAC system.

This stands for
Heating, Ventilating,

and Air Conditioning.

This is very different
than simply purchasing

a window-mounted air
conditioner and turning it on.

There's a lot of
engineering that

goes to designing and
implementing an HVAC system

in these large data centers.

For example, we not
only need to make sure

that the HVAC can support the
amount of heat that's going

to be created by these systems,

we also need to make
sure we have enough power

to run the HVAC.

And we also need to make sure
this is integrated into the fire

system so that we're able to
turn this off automatically

if a fire is detected.

One thing that you'll
notice in a data center

is that the different
aisles of the data center

may be designated as a
hot aisle or a cold aisle.

This hot and cold aisle is
an important designation,

especially as we're installing
new equipment into the data

center.

We want to be sure that we're
installing the equipment

in a way where the hot air is
being blown into the hot aisle

and it's pulling in cold
air from the cold aisle.

Here's a cross reference
of a data center.

On the left and right sides,
we have our HVAC system.

And in this particular
environment,

the cold air is
going under the floor

and the hot air is being
pulled out of the ceiling.

The cycle starts with the
HVAC creating the cold air

and that cold air is
going underneath the floor

in this raised
floor environment.

There are vents and
holes in the floor

that will allow the cold air
to flow into a cold aisle.

This is often the
front of the servers

and the servers are
pulling in that cold air

to cool the inside
of the server itself.

Once that air is
heated up, it will

be sent out the back of the
server into a hot aisle.

And that hot air is going to
rise into the ceiling, where

it will then be pulled back
into the HVAC, re-cooled,

and the entire
system repeats again.

Here's a data center where we
can see both the hot aisles

and the cold aisles.

You'll see the cold aisles
are covered with this plastic

to keep that cold air
inside, and the hot aisles

would be the ones on the
outside without the plastic.

You'll also notice this is a
bit different than the previous

diagram, because there
is a concrete floor,

and there's no way
to have a raised

floor in this environment.

So it looks like they're
blowing the cold air directly

into the cold aisle from above,
it's being pulled through

into a hot aisle, and then it
goes back into the ceiling where

the entire process repeats.

When we install network
cabling, one of our goals

is to not move or touch
that cabling again.

We want to be sure that
once it's installed,

we can trust that
that cable will always

be working optimally.

One of the things
that we'll commonly do

is have all of
the desks that are

on a floor of a building
all have single runs of wire

all the way back to an IDF.

Inside of the IDF closet,
we'll have a patch panel,

and commonly we might have a
patch panel with a 110 block

where we will punch down
those wires onto the back side

of the patch panel.

And on the other
side of the patch

panel will be the traditional
RJ45 modular connectors.

This means that if we need to
connect any user on the floor

to any switch on our
switches, all we have to do

is run the appropriate cable
from the RJ45 connector.

We no longer have to touch
any of the cable that's

running from the back
of this patch panel

to the end user's desk.

So we can begin installing
all of the connections we need

through these patch cables
from the patch panel itself

into the switch that
we might be using.

This also allows us to
address any type of moves,

adds, or changes.

If someone out on the floor
moves to a different desk,

we can simply move
where their patch

cable happens to
be and plug them

into a different connection.

And of course, if we
hire new employees

and we want to make sure that
they have the correct network

connectivity, we don't have
to run additional cables,

because we've already
run those cables.

All we have to do is add new
connections from our patch panel

to the appropriate
switch connection.

Here's what this patch
panel looks like in our IDF.

You can see on this
side of the patch panel,

we have the RJ45 connections.

And we're coming out of
those RJ45 connections,

and we're plugging them
into the switches that

are directly underneath.

This means we can keep all
of those cables in place

between the patch panel and
the desk out on the floor.

All we have to change are the
internal connections inside

of our IDF.

Here's another view
of a patch panel.

This one is connecting
from the patch panel

directly to the switch
that's above it.

And notice there are numbered
connections on that patch panel

so we know exactly
which desk we're

connecting or disconnecting.

There are similar but
slightly different

configurations for fiber optics.

This is a fiber
optic distribution

panel, where we're
bringing in fiber runs

from another building
or another floor,

and we're bringing all of
those back to connections

that we have access to on
the distribution panel.

One of the important
characteristics

when installing fiber optics
is making sure that we

don't exceed the bend radius.

And you'll notice in
this distribution panel

that we are looping together
in a very large loop

the fiber to make sure that we
don't break the fiber by bending

it too far in the panel itself.

And it looks like in
this distribution panel,

we have some additional
fiber that is wrapped around.

We refer to this
as a service loop,

so that if we need to move
this distribution panel

or add additional
fiber, we can simply

extend it with the fiber
that's already run.

This gives us
flexibility in the future

to be able to make
changes without having

to rerun a very expensive
fiber optic connection.

In some of the previous
pictures of the data centers,

you saw that some of
the racks were open.

But there were some racks that
were completely closed that had

locks on the front of the rack.

This is not uncommon in
any type of data center

because it allows the
system administrator

a level of additional
security and control

over the components
inside of the rack.

We'll often install
these racks side by side

directly to each other to
optimize the space that we

have in the data center.

And it's not unusual to have a
door on the front of the rack,

where we can have
a lock and a way

to prevent others from gaining
access to the equipment

inside of the rack.

Here's a good example of racks
that are completely locked up.

You can see in this
case that we do

have ventilation in the front.

There's often ventilation
in the top and the bottom

as well, so that
the equipment inside

is able to be cooled properly.

Here's a closer
view of these racks.

You can see that
each of these racks

has a handle with a lock on it.

And you can see where
you would add the key

to be able to gain access to the
equipment that's on the inside.