Differentiated Services; Defining Diffserv - NETGEAR GS108T-200NAS Software Administration Manual

GS108T and GS110TP Smart Switch Software Administration Manual
To map DSCP values to queues:
1. For each DSCP value, select a hardware queue to associate with the value.
The traffic class is the hardware queue for a port. Higher traffic class values indicate a higher
queue position. Before traffic in a lower queue is sent, it must wait for traffic in higher queues
to be sent. Valid range is 0–3.
2. Click Cancel to cancel the configuration on the screen and reset the data on the screen to the
latest value of the switch.
3. If you make changes to the page, click Apply to apply the changes to the system.

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 are designed to 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 that it will. During times of congestion, packets may be delayed, sent sporadically, or
dropped. For typical Internet applications, such as e-mail and file transfer, a slight degradation in
service is acceptable and in many cases unnoticeable. Conversely, any degradation of service has
undesirable effects on applications with strict timing requirements, such as voice or multimedia.

Defining DiffServ

To use DiffServ for QoS, the Web pages accessible from the Differentiated Services menu page
must first be used to 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 is defined
by a class. The processing is defined by a policy's attributes. Policy attributes may 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.
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v1.0, April 2010
Configuring Quality of Service