Queuing Method; Queuing Method Overview; Strictly Priority Queuing; Weighted Fair Queuing - ZyXEL Communications GS2210-8 User Manual

23.1 Queuing Method Overview

This chapt er int roduces t he queuing m et hods support ed.
Queuing is used t o help solve perform ance degradat ion when t here is net work congest ion. Use t he
Qu e u in g M e t hod screen t o configure queuing algorit hm s for out going t raffic. See also Pr ior it y
Que ue Assignm e nt in Sw it ch Se t up and 8 0 2 .1 p Pr ior it y in Por t Se t u p for relat ed inform at ion.
23.1.1 What You Can Do
Use t he Que ue in g M e t hod screen (
Swit ch. This dist ribut es bandwidt h across t he different t raffic queues.
23.1.2 What You Need to Know
Queuing algorit hm s allow swit ches t o m aint ain separat e queues for packet s from each individual
source or flow and prevent a source from m onopolizing t he bandwidt h.

Strictly Priority Queuing

St rict ly Priorit y Queuing ( SPQ) services queues based on priorit y only. As t raffic com es int o t he
Swit ch, t raffic on t he highest priorit y queue, Q7 is t ransm it t ed first . When t hat queue em pt ies,
t raffic on t he next highest- priorit y queue, Q6 is t ransm it t ed unt il Q6 em pt ies, and t hen t raffic is
t ransm it t ed on Q5 and so on. I f higher priorit y queues never em pt y, t hen t raffic on lower priorit y
queues never get s sent . SPQ does not aut om at ically adapt t o changing net work requirem ent s.

Weighted Fair Queuing

Weight ed Fair Queuing is used t o guarant ee each queue's m inim um bandwidt h based on it s
bandwidt h weight ( port ion) ( t he num ber you configure in t he Weight field) when t here is t raffic
congest ion. WFQ is act ivat ed only when a port has m ore t raffic t han it can handle. Queues wit h
larger weight s get m ore guarant eed bandwidt h t han queues wit h sm aller weight s. This queuing
m echanism is highly efficient in t hat it divides any available bandwidt h across t he different t raffic
queues. By default , t he weight for Q0 is 1, for Q1 is 2, for Q2 is 3, and so on.
Weighted Round Robin Scheduling (WRR)
Round Robin Scheduling services queues on a rot at ing basis and is act ivat ed only when a port has
m ore t raffic t han it can handle. A queue is a given an am ount of bandwidt h irrespect ive of t he
incom ing t raffic on t hat port . This queue t hen m oves t o t he back of t he list . The next queue is given
C
HAPTER
Sect ion 23.2 on page
GS2210 Series User's Guide
183

Queuing Method

184) set priorit ies for t he queues of t he
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