How Queues Work; Overview; Chapter 20 — Tuning Your Switch Performance - Avaya Cajun P550R User Manual

20

Overview

How Queues Work

Cajun P550/P880/P882 Switch User Guide
Tuning Your Switch
Performance
The following information and procedures provided in this chapter
pertain to layer 2 and layer 3 module configurations. Buffer
management features help you to optimize traffic throughput
through the switch fabric.
This chapter provides the following information:
How Queues Work
Managing Buffers and Queues
Frames are buffered in the I/O modules, before and after traversing
the switch. Each queue can hold 256K bytes. (Architecturally they
can support up to 1 MB each).
Each buffer is divided into two queues, one for High-priority Traffic
and one for Normal-priority Traffic. The factory default is for the
high-priority queue uses 20% (51K) of the buffer. The normal-
priority queue uses the remaining 80% (205K). These values can
be modified using either the Web Agent or SNMP.
* Note: When you change these values, you must reboot the
switch before they can take effect.
Less buffer memory gets assigned to the high-priority queue
because the high-priority queue gets serviced more frequently than
the normal-priority queue. Since a frame spends less time on the
high-priority queue, less buffer space is required for the queue.
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