Synchronous Operation (SONET)
If network was completely synchronous, no need for justification (in theory…)
SONET defines a multiplexing hierarchy with exact multiples of data rates:
- OC-3(155.52Mb/s), OC-12(622.08Mb/s), OC-24(1.24416Gb/s), OC-48(2.48832Gb/s)
Assumes synchronized clock
Uses byte interleaving across lesser-speed signals (tributaries)