https://www.juniper.net/documentation/en_US/junos/topics/topic-map/policer-two-rate-three-color.html
Committed information rate (CIR)—Bandwidth limit for guaranteed traffic.
Committed burst size (CBS)—Maximum packet size permitted for bursts of data that exceed the CIR.
Peak information rate (PIR)—Bandwidth limit for peak traffic.
Peak burst size (PBS)—Maximum packet size permitted for bursts of data that exceed the PIR.
Two-rate tricolor marking (two-rate TCM) classifies traffic as belonging to one of three color categories and performs congestion-control actions on the packets based on the color marking:
