NETWORK DESIGN

• Customer requirements

• Network topologies

• Cable choice

• Hardware

• TSB 75

• TSB72

• Nature of traffic– Email– Video

• Security– Of data– Of closets

• EMI– Fluorescent lighting– Motors

Customer Requirements

• Site– Campus– Occupied– Listed– Run lenghts

• Future proofing– Bit rates– EMI– Security

Customer Requirements

• Cost– Installation – Maintenance– Long V's Short term

• Environment– Open plan– Office– Rearrangement

frequency

• CHOICE OF TOPOLOGY DEPENDS ON

– LAYOUT OF BUILDING

– AMOUNT OF EQUIPMENT TO BE CONNECTED

– TYPE OF EQUIPMENT TO BE CONNECTED

– PERFORMANCE REQUIREMENTS

– COST

Network Topologies

Network Topologies

• POINT TO POINT TOPOLOGY

– DIRECT CONNECTION BETWEEN TWO PIECES OF EQUIPMENT

Network Topologies

• BUS TOPOLOGY

– NODES CONNECTED TO A

SINGLE WIRE

– PROBLEMS DIFFICULT TO

ISOLATE

– MAIN CABLE FAILS ENTIRE

NETWORK FAILS

– EASY TO MODIFY

Network Topologies

• STAR TOPOLOGY– SEVERAL DEVICES OR NODES

CONNECTED TO A CENTRAL HUB

– RELIABLE– ONE MALFUNCTIONING NODE DOES

NOT UPSET THE REST OF THE NETWORK

– FLEXIBILITY– NODES CAN BE ADDED OR REMOVED

WITHOUT DISRUPTING SYSTEM

– MORE CABLE REQUIRED THAN A RING OR BUS TOPOLOGY

Network Topologies

• RING TOPOLOGY– NODES CONNECTED IN CLOSED

LOOP

– DATA PASSED FROM NODE TO

NODE TO TARGET DESTINATION

– NODE FAILS - NETWORK MAY

FAIL

– ADDITION OF NODE ONLY WHEN

NETWORK INOPERATIVE

Network Topologies

• PHYSICAL STAR

– RING

CONFIGURATION

– STAR TOPOLOGY

Network Topologies

• COLLAPSED BACKBONE

– SIMILAR TO STAR

Network Topologies

• SHARED NETWORK

Network Topologies

• SWITCHED NETWORK

Network Topologies

• UTP

• FTP, STP, ScTP

• Wireless

• Fibre

Cable Choice

• Horizontal

• EMC (Electromagnetic Compatibility)

• Not resistant to EMI

• Crosstalk

• Not secure

• Cheap

• Carries up to Gigabit speeds

• Distances

UTP

• FTP, STP, ScTP as with UTP but– Better resistance to EMI– Better resistance to Crosstalk– Needs grounding– More expensive (labour)

Screened

• Shared 54Mbps channel

• Ease of installation

• No cable

• Susceptible to EMI

Wireless

• Multimode

• Singlemode

• Secure

• Cost

• Distances

• Bandwidth

Fibre

• Copper

• Fiber

• Multimode / Singlemode

• Future proofing

• Cost

Hybrids

• Central component of star topology

• Regenerates and repeats data

• Extended distances

• Dedicated bandwidth– Switching

• Same media (e.g.. Ethernet)

Switch

• Connects two LANs together• Routes data from source to destination• Reduces network traffic• Improves performance• Relatively high cost• Extended distances• Mixed media (e.g. Ethernet & token ring)• Mixed protocols (.eg. TCP/IP & Novell IPX)

Router

• Zone distribution• Open office cabling

– Consolidation point• Must be at least 15m from telecomms closet• Should be limited to serving a maximum of 12 work areas.• Located is fully accessible, permanent locations

• Was known as TSB72 in EIA standards

Consolidation point

Zone Distribution

• Advantages– Transition point allowed along 90m– Office divided into zones– Only short run at transition point moved when office moves– Less disruption– Less lost productivity– Work area leads can be lengthened if run is less than 90m– Is not meter for meter (see table)– Leads have higher attenuation

TIA/EIA-568-B.1 6.4.2Consolidation point (TSB 75)

Patch leads

• The connection from the CP to the TO uses solid core copper.

• The option is available to use a stranded cable but the total maximum length of your link is reduced

• Stranded cable has 20% higher attenuation so the total length of your link must be reduced

• Option to use a 26AWG cable– 50% higher attenuation– must adjust figure in table accordingly

• Centralised Optical Architecture– Previously called TSB 72– Usually for fibre systems– Can use copper– 300 meter length limit (including patch cord in TIA/EIA version

only)– ISO have 3 link lengths of 300, 500 & 2000 m

• Also a number of application link lengths

– Electronics on one floor– Higher densities on hubs– Less space used

11801 and TIA/EIA-568-B.1