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Network Specification

Network Specification

• Network Configuration

• Cabling

• Network components - user supplied

Network Configuration

Terminology

• Repeater
  • repeats signal from one cable section to another thus several subnets become a single subnet

  • increases the maximum length of the LAN

• Bridge
  • connect networks which use dissimilar protocols

  • network composed of various types of media such as coaxial, fibre, serial

  • do not carry out interpretation of information

  • two bridged LANs effectively become one LAN

  • some are used to control traffic and security

  • by localising traffic performance may be improved

  • some can perform routing functions

• Router
  • Protocol specific

  • provides physical and logical route from one network to another

  • uses information relating to network topology to choose the best route for a packet to follow, therefore the contents of the packet are examined

  • can link different network types - bridging style functions

  • can exchange information between each other relating to network conditions

• Gateway
  • combination of hardware and software to connect, normally, incompatible networks and devices

  • example: device to link ethernet to X25

• Hub
  • centre of a star topology network or cabling system

  • used with UTP and fibre optics

  • ethernet hubs currently broadcast to all workstations on the hub but newer hubs will provide routing type functions, that is, filter and block packets

Recommendations

• A departmental sub-net connected to a router port or gateway machine

• Alternatively configure one machine as a router
  • Requires 2 network interfaces (eg.: 2 ethernet cards: one ethernet and one ATM card: etc.)

  • Most systems require some reconfiguring but much should be automatic eg. starting routed

• A departmental sub-net interconnected via a hub

• Avoid where possible a sub-net with a large number of machines especially those extended using a repeater

Cabling

What cabling is being used?

• Ethernet
  • thick wire (unlikely)

  • thin wire (wall mounted sockets or loose cabling)

  • UTP - Unshielded Twisted Pair

• FDDI - Fibre Distributed Data Interface

• ATM - fibre

Cable Performance

• .....

Network Components

User Supplied

• Transceiver: provides connection between the computer and the network. Transceivers are available to support different networks and media. These can be standalone units or incorporated into the computer. Also known as MAU (Medium Attachment Unit).

• Drop cable: also called an AUI (Attachment Unit Interface) cable, it is required to connect some transceivers to the computer.

• Interface card: this is essentially an in-box transceiver. many workstations now have an ethernet interface card. ATM and FDDI connection are only available via an interface card.