Case Study: Investigate Networking Media, Access Methods, Topologies

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Case StudyInvestigate Networking Media, Access
Methods, Topologies
Presented byNick Wallingford
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Case Exercise
ABC Enterprises is a manufacturing company with
two basic areas, office and manufacturing. The
company is relocating its office and factory
area. The previous tenants have left a coaxial
cable in a bus physical topology from their
Ethernet network which connected some of their
offices. The factory area is to house arc
welders, drilling, milling and other heavy
machining equipment involving high voltages and
currents. Some additional office areas and the
factory areas are to be wired for a LAN.
Recommend a cost effective solution for the
media and topologies to be used for their LAN.
You are to support your solution with reasons for
the media, access method and the topology
selected.
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Mark Up to Identify Critical Elements
ABC Enterprises is a manufacturing company with
two basic areas, office and manufacturing. The
company is relocating its office and factory
area. The previous tenants have left a coaxial
cable in a bus physical topology from their
Ethernet network which connected some of their
offices. The factory area is to house arc
welders, drilling, milling and other heavy
machining equipment involving high voltages and
currents. Some additional office areas and the
factory areas are to be wired for a LAN.
Recommend a cost effective solution for the
media and topologies to be used for their LAN.
You are to support your solution with reasons for
the media, access method and the topology
selected.
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Key Points and Commentary

• Manufacturing company relocating office and
  factory
• Two distinct areas with inherent differences
• Assume reasonably close proximity
• Office area has existing coaxial cable
• Need decision about re-use or scrap
• Cost of testing vs cost of replacement
• Factory area has electromagetic interference
• Media must not be susceptible or affected, so UTP
  (even if shielded) would not be used
• Wireless considered
• Fiber optic ultimately selected
• Process control machinery in the factory?
• Need for predetermined and predictable response
  times?
• Must not be affected by high traffic/packet
  collisions in the network
• Assume does not require deterministic response

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Case Exercise Solution Arrived At

• ABC Enterprises at Auckland finally went in for
  this solution
• Media - UTP for the additional office work
  positions connected using a hub. Fiber optic in
  the factory area using a hub
• Topology - Star for the additions in the factory
  and the offices with the older co-axial
  integrated using an Ethernet hub
• Access method - CSMA/CD

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Case Exercise Additional Narrative

• The solution worked only for a period of a year
  until some major changes took place. These
  included modernising the factory area with CNC
  machines, a two-fold increase in the office
  personnel at Auckland using computers and the
  opening of branch offices in Wellington, Hamilton
  and Gisborne which had their own LANs. The
  interim solution adopted using dial up networking
  to establish data communication between the
  branch offices LANs and the head office at
  Auckland seemed unsatisfactory most of the time.
• You have been selected as the Networks Manager
  and are expected to improve the existing
  situation along with future recommendations to
  cover future growth.

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Mark Up to Identify Critical Elements

• The solution worked only for a period of a year
  until some major changes took place. These
  included modernising the factory area with CNC
  machines, a two-fold increase in the office
  personnel at Auckland using computers and the
  opening of branch offices in Wellington, Hamilton
  and Gisborne which had their own LANs. The
  interim solution adopted using dial up networking
  to establish data communication between the
  branch offices LANs and the head office at
  Auckland seemed unsatisfactory most of the time.
• You have been selected as the Networks Manager
  and are expected to improve the existing
  situation along with future recommendations to
  cover future growth.

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Key Points and Commentary

• CNC machines in factory
• Probably require control and monitoring from
  office area
• Electromagnetic interference still needs
  consideration
• PC users in office have risen dramatically
• Probably requires some separation so collision
  frequency is reduced
• May well continue into future
• Three regional offices, each with own LAN
• Hopefully developed using similar/same equipment
  and software
• Dial up networking with regional offices not
  satisfactory WAN requires re-development
• Nature of traffic needs consideration
• Dedicated line probably too expensive though
  workable

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Key to Diagram
Server
Router
Switch
PC/workstation
10/100 Mb Hub
Frame Relay
Frame relay network
Computer Numeric Control (CNC) machine
Process control workstation
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