It can control the flow of traffic out of the network It can control how users connect to web sites And which files are permitted to leave the network Allows the monitoring of users’ Internet access Filters all messages entering / leaving the network Examines each message and blocks those that do not meet security criteria Prevents unauthorised external access Prevents unauthorised internal access Prevents malicious access Prevents attacks / hacking May act as a router, forwarding packets between the LAN and the Internet Fibre Optic Cable Supports broadband / multiple data transmissions Flexible medium and can be used in awkward layouts Minimal signal loss over distance Uses light Cable consists of glass or plastic wires / cores / filaments Bundled together Encased in a jacket Each core has a mirror-lined wall or cladding Which reflects light back along the core (total internal reflection) Minimises signal degradation is transmitted in pulses represents a range of frequencies / that is modulated The cable can vary in length from a few metres to hundreds of kilometres Impervious to electromagnetic interference Not susceptible to interference Signal difficult to intercept without destroying it Converting a network into a wireless network Each PC will require a wireless network adapter / card With a radio transmitter / receiver / antenna To communicate with the hub / server A wireless router / hub / switch will be required With a radio transmitter / receiver / antenna To communicate with each PC A wireless may be used To connect directly to the ISP / Internet Appropriate software / drivers will be required Bus Network All computers are connected to a single cable or backbone Data travels from the source in both directions along the bus
It can control the flow of traffic out of the network It can control how users connect to web sites And which files are permitted to leave the network Allows the monitoring of users’ Internet access Filters all messages entering / leaving the network Examines each message and blocks those that do not meet security criteria Prevents unauthorised external access Prevents unauthorised internal access Prevents malicious access Prevents attacks / hacking May act as a router, forwarding packets between the LAN and the Internet Fibre Optic Cable Supports broadband / multiple data transmissions Flexible medium and can be used in awkward layouts Minimal signal loss over distance Uses light Cable consists of glass or plastic wires / cores / filaments Bundled together Encased in a jacket Each core has a mirror-lined wall or cladding Which reflects light back along the core (total internal reflection) Minimises signal degradation is transmitted in pulses represents a range of frequencies / that is modulated The cable can vary in length from a few metres to hundreds of kilometres Impervious to electromagnetic interference Not susceptible to interference Signal difficult to intercept without destroying it Converting a network into a wireless network Each PC will require a wireless network adapter / card With a radio transmitter / receiver / antenna To communicate with the hub / server A wireless router / hub / switch will be required With a radio transmitter / receiver / antenna To communicate with each PC A wireless may be used To connect directly to the ISP / Internet Appropriate software / drivers will be required Bus Network All computers are connected to a single cable or backbone Data travels from the source in both directions along the bus
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