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Differentiated services, Defining diffserv – NETGEAR M4350-24F4V 24-Port 10G SFP+ Managed AV Network Switch User Manual

Page 595

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Table 148. CoS Interface Queue Drop Precedence Status

Description

Field

The CoS interface.

Interface

The queue ID.

Queue ID

The drop precedence level.

Drop Precedence Level

The WRED minimum queue threshold value.

WRED Minimum Threshold

The WRED maximum queue threshold value.

WRED Maximum Threshold

The WRED packet drop probability value.

WRED Drop Probability Scale

Differentiated Services

The QoS feature contains Differentiated Services (DiffServ) support that allows traffic to
be classified into streams and given certain QoS treatment in accordance with defined
per-hop behaviors.

Standard IP-based networks provide best-effort data delivery service. Best-effort service
implies that the network delivers the data in a timely fashion, although there is no
guarantee. If congestion occurs, packets might be delayed, sent sporadically, or dropped.
For typical Internet applications, such as email and file transfers, a slight degradation
in service is acceptable and in many cases unnoticeable. However, any degradation of
service can negatively affect applications with strict timing requirements, such as voice
and multimedia.

Defining DiffServ

To use DiffServ for QoS, you must first define the following categories and their criteria:

1. Class: Create classes and define class criteria.

2. Policy: Create policies, associate classes with policies, and define policy statements.

3. Service: Add a policy to an inbound interface.

Packets are classified and processed based on defined criteria. The classification criteria
are defined by a class. The processing is defined by a policy’s attributes. Policy attributes
can be defined on a per-class instance basis, and it is these attributes that are applied
when a match occurs. A policy can contain multiples classes. When the policy is active,
the actions taken depend on which class matches the packet.
Note the following about the DiffServ process:

Main User Manual

595

Configure Quality of Service

Fully Managed Switches M4350 Series Main User Manual