Refer to the exhibit. Based on this configuration, what type of marker is achieved?
A.
Single-rate, two-color marker
B.
Three-rate, two-color marker
C.
Two-rate, three-color marker
D.
Single-rate, three-color marker
Explanation:
The Two Rate Three Color Marker (trTCM) meters an IP packet stream and marks its packets either green, yellow, or red. A packet is marked red if it exceeds the Peak Information Rate (PIR). Otherwise it is marked either yellow or green depending on whether it exceeds or doesn’t exceed the Committed Information Rate (CIR). The trTCM is useful, for example, for ingress policing of a service, where a peak rate needs to be enforced separately from a committed rate.The operation of the marker is described by two rate values. The committed information rate (CIR) and the excess information rate (EIR). CIR and EIR define the token generation rate of a token bucket with size that is equal to committed burst size (CBS) and excess burst size (EBS), respectively. The CBS and EBS are measured in bytes and must configure to be greater than the expected maximum length of the incoming PDU. The CIR and EIR are both measured in bits/s. The CIR and EIR can be set independently of each other. Alternatively, the CIR and EIR can be linked together by defining a burst duration parameter, T, where T=CBS/CIR=EBS/EIR.
The behavior of the meter is defined in terms of its mode and two token buckets, C and E, with the rates, CIR and EIR, respectively, and maximum sizes CBS and EBS. The token buckets C and E are initially (at time 0) full; i.e., the token count Tc(0) = CBS and Te(0) = EBS. Thereafter, the token count Tc is incremented by one CIR times per second (up to CBS), and the token count Te is incremented by one EIR times per second (up to EBS).