ZyXEL P-870MH-C1 User Guide - Page 215

Quality of Service QoS, P-870HN-5xb User's Guide

Page 215 highlights

Chapter 16 Quality of Service (QoS) The trTCM is based on the token bucket filter and has two token buckets (Committed Burst Size (CBS) and Peak Burst Size (PBS)). Tokens are generated and added into the two buckets at the CIR and PIR respectively. All packets are evaluated against the PIR. If a packet exceeds the PIR it is marked red. Otherwise it is evaluated against the CIR. If it exceeds the CIR then it is marked yellow. Finally, if it is below the CIR then it is marked green. The following shows how tokens work with incoming packets in trTCM: • A packet arrives. If the number of tokens in the PBS bucket is less than the size of the packet (in bytes), the packet is marked red and may be dropped regardless of the CBS bucket. No tokens are removed if the packet is dropped. • If the PBS bucket has enough tokens, the Device checks the CBS bucket. The packet is marked green and can be transmitted if the number of tokens in the CBS bucket is equal to or greater than the size of the packet (in bytes). Otherwise, the packet is marked yellow. P-870HN-5xb User's Guide 215

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Chapter 16 Quality of Service (QoS)
P-870HN-5xb User’s Guide
215
The trTCM is based on the token bucket filter and has two token buckets
(Committed Burst Size (CBS) and Peak Burst Size (PBS)). Tokens are generated
and added into the two buckets at the CIR and PIR respectively.
All packets are evaluated against the PIR. If a packet exceeds the PIR it is marked
red. Otherwise it is evaluated against the CIR. If it exceeds the CIR then it is
marked yellow. Finally, if it is below the CIR then it is marked green.
The following shows how tokens work with incoming packets in trTCM:
A packet arrives. If the number of tokens in the PBS bucket is less than the size
of the packet (in bytes), the packet is marked red and may be dropped
regardless of the CBS bucket. No tokens are removed if the packet is dropped.
If the PBS bucket has enough tokens, the Device checks the CBS bucket. The
packet is marked green and can be transmitted if the number of tokens in the
CBS bucket is equal to or greater than the size of the packet (in bytes).
Otherwise, the packet is marked yellow.