Network Performance

Network Performance

1. Bandwidth

   • how much data can be transferred in a given time
   • mesured in: kbps, mbps, gbps
     • basic copper wire based broadband- 2 to 10mbps
     • Fibre optic based broadband- 10-75mbps
     • Ethernet wired network- cat-5 cable- 10 to 100Mbps
     • ethernet wired network- cat-6 cable- 1Gbps to 10Gbps
     • standard wifi- 54 to 150 Mbps
     • fast wifi- 900Mbps
   • high performance networks have a high bandwidth

2. Contention ratio

   • The ratio of users compared to the avaliable bandwidth
   • high performance networks have a low contention ratio
     • 1:1

3. Wired Peformance

   • Ethernet Cables
     • Cat-5 (slower)
     • Cat-6 (faster)
   • Fibre optic cables
     • Transfer data using light reflected inside the cable
     • High bandwidth
       • Expensive
     • bandwidth limited to connected equipment

4. Bands and Channels

   • Wifi works in two frequency bands
     • 2.4Ghz
       • carry several non-overlapping channels
     • 5ghz
       • Carries many non-overlapping channels
       • Has a higher capacity
       • More expensive
       • Shorter range
     • divided into seperate channels
       • number of channels is regulated by the law

5. Wifi performance

   • Radio Interference
     • if something is transmitting on the same frequency as a wifi network
       • microwaves
   • Blocked by wallls
   • Limited connections
     • only so many connections
     • limits how many people can be on the network at once

6. Errors

   • happens when a 0 is recienced as a 1
     • or vice versa
   • causes
     • signal too weak
       • the longer the cable th weaker the connection
         • causing errors
     • interference

7. Latency

   • delay
     • every switch and router adds to the delay
       • connection changes by the second
         • as the router forms a route
         • bits arrrive in a different order than they were sent
   • small networks dont have much delay
     • everything is close together
   • high performance networks have a low latency