Networking as we knew it… Communications networks were traditionally constructed to precisely meet the requirements of the intended service For example: The dynamics of the human voice and the telephone network: Voice range covers 300 Hz to 3500 Hz Poor high frequency response reduces intelligibility Dynamic range of 70db Delay within 400 ms Limited Total Harmonic Distortion Digitally, voice can be mapped with 8000 samples per second, with each sample quantized to 256 discrete levels: 8KHz of 8 bit samples The PSTN is a time switched network with a base 125usec clock pulse Digital Circuits are derived from these time-switched 64K synchronized bit streams, using multiples of this basic service atom Voice networks are highly constrained systems that operate to a Highest Common Factor service model
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