A law made by Dr. John Little, MIT, 1954. $\huge \text{Occupancy} = \text{Latency} \cdot \text{Throughput } $ - *Occupancy*: How many messages are extant in the system (bits) - [[Network Latency|Latency]]: How long it takes for a mesage to get through (time, seconds) - [[Throughput (Network) | Throughput]]: How much data can we send per second (bits / second)