QoS Policing Token Usage

Policing uses the concepts of tokens and token buckets to regulate traffic flow. Tokens accumulate in a bucket over time up to a maximum size, representing the amount of data that can be transmitted.

When a packet arrives:

  • If enough tokens exist to cover the packet size, the packet is transmitted and tokens are removed.
  • If insufficient tokens exist, the packet is marked as exceeding and may be dropped based on policy, but no tokens are removed.

Tokens are intentionally preserved when packets exceed to accommodate bursty traffic patterns. This allows:

  • Temporary transmission above CIR (Committed Information Rate) while tokens remain
  • Natural burst handling until bucket depletes.
  • Token replenishment over time for future bursts.

https://networklessons.com/quality-of-service/qos-traffic-policing-explained/