Installation Guide

Table Of Contents
Task 11: Configuring quality of service
Task 11: Configuring quality of service
Maximum Information Rate (MIR) Parameters
Point-to-multipoint links use the following MIR parameters for bandwidth
management:
Sustained Uplink Data Rate (kbps)
Uplink Burst Allocation (kb)
Sustained Downlink Data Rate (kbps)
Downlink Burst Allocation (kb)
Max Burst Downlink Data Rate (kbps)
Max Burst Uplink Data Rate (kbps)
You can independently set each of these parameters per AP or per SM.
Token Bucket Algorithm
The software uses a
token bucket
algorithm that has the following features:
Stores credits (tokens) for the SM to spend on bandwidth for reception or transmission.
Drains tokens during reception or transmission.
Refills with tokens at the sustained rate set by the network operator.
For each token, the SM can send toward the network in the uplink (or the AP can
send toward the SM in the downlink) an equivalent number of kilobits. Two buckets
determine the permitted throughput: one in the SM for uplink and one in the AP for
downlink.
The applicable set of Uplink Burst Allocation and Downlink Burst Allocation
parameters determine the
number
of tokens that can fill each bucket. When the SM
transmits (or the AP transmits) a packet, the equivalent number of tokens is
removed from the uplink (or downlink) bucket.
Except when full, the bucket is continuously being refilled with tokens at
rates
that
the applicable set of Sustained Uplink Data Rate and Sustained Downlink Data
Rate parameters specify. The bucket often drains at a rate that is much faster than
the sustained data rate but can refill at only the sustained data rate. Thus, the
effects of the allocation and rate parameters on packet delay are as follows:
The burst allocation affects how many kilobits are processed before packet delay is
imposed.
The sustained data rate affects the packet delay that is imposed.
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pmp-0957 (April 2015)