Network Design Issues

Design and Documentation

Prepared by: Aline L. Mendoza

Network Design Issues

Gather information about the organizationMake 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

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

Problem-solving matrices

Wiring Closet Specifications

Sizing for Wiring Closet

Wiring Closet Specification:Environmental 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

Walls floors and ceilings

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.

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

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

Temperature and Humidity

Temperature should be maintained at 21°C 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.

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 room’s 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.

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.

Full Equipment Cabinet

1.8 m

.66 m

.74 m

76.2 cm

Cable access and support

10.2 cm

15.2 cm (within the wall)

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

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. dentify 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.

Identifying Potential Wiring Closets

Identifying MDF in a Multi-Story Building

Identifying MDF in a Multi-Building Campus

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

Networking Media for Backbone Cabling

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

Horizontal and Backbone Cabling (Type A)

MDF

IDF

3000m

Horizontal and Backbone Cabling (Type B)

2500m

500m

Horizontal and Backbone Cabling