Let the three variables:
- is the bandwidth (bits/s)
- is the size of a packet (bits)
- is the arrival rate (count/sec)
Then we can know that:
- is the traffic arrival rate (bits/s)
- If , the bandwidth is much higher than the traffic. No problem.
- If , the bandwidth struggles to digest the traffic. Congestion begins.
- If , more traffic comes than the bandwidth's capability. Congestion piles up.