Network Design Issues

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Network Design Issues

• Design and Documentation

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Network Design Issues

• Gather information about the organization
• Make a detailed analysis and assessment of the
  current and projected requirements of those
  people who will be using the network.
• Identify the resources and constraints of the
  organization.
• Documentation

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Documentation that you should create as you
design a network

• engineering journal
• logical topology
• physical topology
• cut sheets
• problem-solving matrices
• labeled outlets
• labeled cable runs
• summary of outlets and cable runs
• summary of devices, MAC addresses, and IP
  addresses

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Problem-solving matrices
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Wiring Closet Specifications
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Sizing for Wiring Closet
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Wiring Closet SpecificationEnvironmental
Specification

• Any room, or closet that you choose to serve as a
  wiring closet should adhere to guidelines
  governing such items as the following 
• materials for walls, floors, and ceilings
• temperature and humidity
• locations and types of lighting
• power outlets
• room and equipment access
• cable access and support

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Walls floors and ceilings
 20mm A-C plywood that is at least 2.4m high.
30.5 cm

• Rooms must not have a dropped, or false, ceiling.
• If MDF POP may be located inside the room. The
  interior wall of the POP site, behind the PBX,
  should be covered from floor to ceiling with 20mm
  plywood, with minimum of 4.6 m of wall space

• MDF - 4.8 kPA (100 lb/ft²).
• IDF - 2.4 kPA (50 lb/ft²)
• If possible should be raised
• tiled or some other type of finished surface.

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Temperature and Humidity

• Temperature should be maintained at 21C when all
  equipments are in operation
• Humidity should be maintained between 30-50.
• no water or steam pipes running through or above
  the room, with the exception of a sprinkler
  system.

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Lighting fixtures and power outlets

• if the closet serves as the MDF - minimum of two
  dedicated, non-switched, AC duplex electrical
  outlet receptacles, each on separate circuits. It
  should also have at least one duplex power outlet
  positioned every 1.8 m along each wall of the
  room, and should be positioned 150 mm above the
  floor.
• A wall switch, that controls the rooms main
  lighting, should be placed immediately inside the
  door.
• Lighting requirements for a telecommunications
  closet specify a minimum of 500 lx (brightness of
  light equal to 50 foot candles), and that light
  fixtures be mounted a minimum of 2.6 m above the
  floor.

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Room and equipment access

• The door of a wiring closet should be at least .9
  m wide, and should swing open out of the room.
• A wiring hub and patch panel may be mounted to a
  wall with a hinged wall bracket, or with a
  distribution rack
• Hinged wall bracket - 48 cm for the panel to
  swing out from the wall.
• Distribution rack - minimum 15.2 cm of wall
  clearance for the equipment, plus another
  30.5-45.5 cm for physical access by workmen and
  repairmen. A 55.9 cm floor plate, used to mount
  the distribution rack, will provide stability,
• If the patch panel, hub and other equipment are
  mounted in a full equipment cabinet, they require
  at least 76.2 cm of clearance in front, in order
  for the door to swing open. Typically, such
  equipment cabinets are 1.8 m high x .74 m wide x
  .66 m deep.

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Full Equipment Cabinet
76.2 cm
1.8 m
.74 m
.66 m
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Cable access and support
15.2 cm (within the wall)
10.2 cm
Any wall/ceiling openings that provide access for
the conduit, or sleeved core, must be sealed with
smoke and flame-retardant materials that meet all
applicable codes
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Identifying Potential Wiring Closets

• Draw a floor plan of the building to scale, and
  identify all of the devices that will be
  connected to the network.
• Identify secure locations that are close to the
  POP, that can serve as either the sole wiring
  closet, or as the MDF
• If IDFs are required. The POP is where
  telecommunications services, provided by the
  telephone company, connect to the building's
  communication facilities.
• Determining number of wiring closets
• Use your compass to draw circles that represent a
  radius of 50 m. from each of the potential hub
  locations.
• Are there any potential hub locations whose
  catchment areas substantially overlap? If so, you
  could probably eliminate one of the hub
  locations.
• Are there any potential hub locations whose
  catchment areas can contain all of the devices
  that are to be connected to the network? If so,
  then one of them could probably serve as the
  wiring closet for the entire building
• If you will need more than one hub in order to
  provide adequate coverage for all of the devices
  that will be connected to the network, check to
  see if one of them is closer to the POP than the
  other(s)? If so, you will probably want to select
  it to serve as the MDF.

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Identifying Potential Wiring Closets
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Identifying MDF in a Multi-Story Building
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Identifying MDF in a Multi-Building Campus
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Backbone cabling consists of the following

• backbone cabling runs
• intermediate and main cross-connects
• mechanical terminations
• patch cords used for backbone-to-backbone
  cross-connections
• vertical networking media between wiring closets
  on different floors
• networking media between the MDF and the POP
• networking media used between buildings in a
  multi-building campus

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Networking Media for Backbone Cabling

• 100 W UTP (four-pair)
• 150 W STP-A (two-pair)
• 62.5/125 µ optical fiber
• single-mode optical fiber

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Horizontal and Backbone Cabling (Type A)
MDF
IDF
3000m
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Horizontal and Backbone Cabling (Type B)
2500m
500m
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Horizontal and Backbone Cabling