Split offered traffic into conforming, exceeding and violating rates for a two-rate three-colour policer.
A two-rate three-colour policer runs two token buckets. Traffic up to CIR is green, traffic between CIR and PIR is yellow and re-marked for early discard, and anything beyond PIR is dropped immediately. Burst tolerance is simply how long the committed bucket can cover the excess. Unlike a shaper, a policer drops rather than buffers, so an undersized CBS turns normal TCP burstiness into visible packet loss even when the average rate is well under contract.
Traffic Policing
green = min(offered, CIR); yellow = min(offered − CIR, PIR − CIR); red = offered − PIR; burst tolerance ms = burst size in bits ÷ the matching rate.
green = min(offered, CIR); yellow = min(offered − CIR, PIR − CIR); red = offered − PIR; burst tolerance ms = burst size in bits ÷ the matching rate. A two-rate three-colour policer runs two token buckets. Traffic up to CIR is green, traffic between CIR and PIR is yellow and re-marked for early discard, and anything beyond PIR is dropped immediately. Burst tolerance is simply how long the committed bucket can cover the excess.
Unlike a shaper, a policer drops rather than buffers, so an undersized CBS turns normal TCP burstiness into visible packet loss even when the average rate is well under contract.
This calculator takes 5 inputs: Offered rate, Committed rate (CIR), Peak rate (PIR), Committed burst size (CBS), Excess burst size (EBS). The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.