7.2.5

• Bandwidth


  The rate of data transfer for a fixed period of time
• Bandwidth

  • The wider of a communication band the more the data can flow through it simultaneously
• Expressing Bandwidth

  • Bandwidth was measured in bits per second (bps)
  • It is now measured in units that are denoted with metric prefixes such as Mbps (megabits per second)
• Bandwidth determines the overall speed of a connection
• The lowest bandwidth in the communication chain between two computers determines the maximum speed of a connection
• Bandwidth units

  • Megabits (Mbits)
  • Megabytes (MB)
  • Gigabytes (GB)
  • Terabytes (TB)
  • Kilobits (Kbits)
  • Kilobytes (KB)
  • Gigabits (Gbits)
• Latency


  The amount of time it takes for data to travel from one point to another
• Latency

  • Latency is usually measured as a round trip (the time taken for information to get to its destination and back again)
  • It is important because a computer sends a limited amount of data to its destination and then waits for acknowledgement to come back before sending any more
  • The round trip delay has a key impact on the performance of a network
• Latency

  Drives throughput (the maximum amount of data that can be transmitted)
• Bandwidth


  Limits the number of simultaneous conversations that can be supported on a network
• Latency

  Determines the responsiveness of the network (how fast the conversation can be had)