Queuing Method; Chapter 25 Queuing Method; Queuing Method Overview; Strictly Priority Queuing - ZyXEL Communications MS-7206 - EDITION 1 Manual

C
H A P T E R
This chapter introduces the queuing methods supported and then explains the
screen for configuring them.

25.1 Queuing Method Overview

Queuing is used to help solve performance degradation when there is network
congestion. Use the Queuing Method screen to configure queuing algorithms for
outgoing traffic. See also Priority Queue Assignment in Switch Setup
(Chapter 9 on page
79) for related information.
Queuing algorithms allow switches to maintain separate queues for packets from
each individual source or flow and prevent a source from monopolizing the
bandwidth.

25.1.1 Strictly Priority Queuing

Strictly Priority Queuing (SPQ) services queues based on priority only. As traffic
comes into the switch, traffic on the highest priority queue, Q7 is transmitted first.
When that queue empties, traffic on the next highest-priority queue, Q6 is
transmitted until Q6 empties, and then traffic is transmitted on Q5 and so on. If
higher priority queues never empty, then traffic on lower priority queues never
gets sent. SPQ does not automatically adapt to changing network requirements.

25.1.2 Weighted Round Robin Scheduling (WRR)

Round Robin Scheduling services queues on a rotating basis and is activated only
when a port has more traffic than it can handle. A queue is a given an amount of
bandwidth irrespective of the incoming traffic on that port. This queue then moves
to the back of the list. The next queue is given an equal amount of bandwidth, and
then moves to the end of the list; and so on, depending on the number of queues
being used. This works in a looping fashion until a queue is empty.
MS-7206 User's Guide

Queuing Method

69) and 802.1p Priority in Port Setup
25
(Chapter 12 on page
169