Network Essentials

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Network Essentials

• Presented by the
• Knox County Schools
• The Network Team

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The mighty network
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Terminology

• Networking seems to have a language of its own.
  The next few slides should help to define what
  some of those terms.

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• Patch Cable
• The cable that connects the computer to the rest
  of the network. The patch cable connects to the
  network drop

5

• Network Drop
• The place where the user plugs in one end of the
  patch cable. The other end of the patch cable is
  plugged into the computer. Note one should take
  care to not connect the patch cable to the drop
  where people can trip over it.

The numbers above each drop correspond to cables
in the network cabinet. Good to know when
tracking down problems.
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• The Network drop has cables that run from the
  drop to the network cabinet. These cables
  usually join together with other cables to form a
  big bundle by the time they enter the cabinet.

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The Network cabinet
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• Anatomy of a network cabinet.
• One item inside the cabinet is Patch Panel.
  Patch panels are the place where the network drop
  cables all join together. The numbers on the
  patch panel corresponds to the numbers on a
  network drop. Usually there are 24 ports on each
  panel. Patch panels are connected to electronics
  by patch cables.

The patch panels are a good way to concentrate
all network connections in one central place.
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• Switches and/or Hubs
• Switches and hubs help direct the network
  traffic. These devices connect all of the
  different computers together. One will notice
  many blinking lights on each switch. The lights
  can help diagnose various network problems. The
  next slide will discuss what some of the lights
  mean.

Switches and hubs are expensive and sensitive to
heat and dust. It is important for the network
cabinets to remain clean and have good
ventilation.
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• There are usually two types of lights on the
  switches.
• Packet lights blink on and off as data travels
  through the network.
• Status lights stay on constantly. Status lights
  will only be lit when a printer or computer is
  attached to them.

Packet lights
Status light
When a switch has no lights on it or when all of
the lights are on with no flashing, there is a
network problem. Call the network team.
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• Switch Lights can tell which drops have computers
  connected to the network.

In our drawing, one can see that the status
lights 8, 9, 12, 19, 22, and 24 all have devices
attached to them because they are all lit up.
Ports 12, 19, and 24 all have their packet lights
lit and are having data sent to them. The packet
lights should flash on and off.
Packet Status
7 8 9 10 11 12
Packet Status
19 20 21 22 23 24
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• One can trace the cables in the cabinet when one
  is trying to determine if a drop is active. One
  can trace the patch cord from the port number to
  where it is plugged in, to the location where it
  is plugged into the switch. If that port light
  is on, the drop is working.

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• The red cables in your cabinet are called
  Crossover Cables and connect all of the switches
  together. The crossover cables are usually
  plugged into port 24 of each switch. One switch
  in the cabinet should have several crossover
  cables plugged into it. These cables come from
  the other switches.

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• Another item that one will find in some network
  cabinets is the router. The router is a black
  box with a silver front with very few ports
  visible. The router has a patch cable that
  attaches to one switch inside of the cabinet.

The router connects the schools network to the
rest of the world. For a person to connect from
a classroom to an internet site, that data has to
pass through the router.
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MDF vs IDF

• The MDF is the main network cabinet in a
  building. The router is usually located in the
  MDF. Some schools have only one cabinet and that
  is the MDF. Schools with more that none cabinet
  have an MDF and IDFs

• The IDF is a cabinet that is located a long
  distance away from the MDF. IDFs and MDFs are
  usually connected by copper or fiber cables.
  IDFs are usually located in opposite ends of the
  building from the MDF.

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• The orange cables that are inside some network
  cabinets are fiber optic cables. Some fiber
  optic cables are attached to switches (top
  picture) and other fiber optic cable will be
  attached to part called an LIU (the bottom
  picture).

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• As mentioned earlier, the switches and hubs are
  sensitive to dust and heat. Many cabinets have
  filters in the bottom of the cabinets and fans on
  the top of the units. The cabinet doors should
  remain closed to help improve ventilation and
  promote cleanliness. Cool and clean switches will
  last longer.

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Mini-Switches

• Some classrooms and mobile labs have a 5 or 8
  port switch that allows several machines to
  attach to the switch. Special care needs to be
  taken when setting up these switches.

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• The front of mini-switch has lights that tell
  which ports that have computers attached to them.

The rear of the mini switch has the power
connection and either 5 or 8 ports to connect
to computers. One port in the back of
the mini-switch must be used to connect to a
network drop.
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• Mini-switches can cause serious network problems
  if more than one patch cable from a single
  mini-switch is plugged into network drops. This
  is often done by accident but can cause loss of
  connectivity by network users throughout the
  whole school.

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• Please contact us if you have problems.
• The Network Team
• Larry Brothers- brothersl_at_k12tn.net
• Ed Dennison- dennisone_at_k12tn.net
• Gary Bucci- buccig _at_k12tn.net
• Dan Foster- fosterd6 _at_k12tn.net
• Office phone [phone]