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CITS3002 Computer Networks |
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Metrics Of Network MeasurementThere are two components to performance - latency and bandwidth. We always want high bandwidth and low latency, but can't always get both together.
The latency of a message is the total time for the whole message to arrive:
TLatency = TPropagation + TTransmit + TQueue TPropagation = distance / speed-of-propagation-in-medium TTransmit = message-size / bandwidth TQueue = time-spent-in-local-and-remote-operating-system-and-switch-queues On prefixesIn networking and data storage (devices), the prefix Mega means 106, at least when referring to throughput and bandwidth. We always use powers of 10 when referring to frequencies, measured in Hertz. When talking about the size of a message, buffer, file, or other computer-storage item, we use Mega to mean 220. Similar rules apply for the prefixes Kilo and Giga.See: Transmission time [Wikipedia], Binary prefix [Wikipedia], and Grace Hopper Explains a Nanosecond.
CITS3002 Computer Networks, Lecture 2, The Physical Layer, Errors detection and correction, p2, 6th March 2024.
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