Netgear M5300-52G (GSM7252S) - ProSAFE 48-port Gigabit L2+ Managed Stackable Switch 관리자 가이드
DiffServ
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Managed Switches
Differentiated Services Concepts
Differentiated services (DiffServ) is one technique for implementing Quality of Service (QoS)
policies. Using DiffServ in your network allows you to directly configure the relevant
parameters on the switches and routers rather than using a resource reservation
protocol.This section explains how to configure the managed switch to identify which traffic
class a packet belongs to, and how it should be handled to provide the quality of service you
want. As implemented on the managed switch, DiffServ allows you to control what traffic is
accepted and what traffic is discarded.
policies. Using DiffServ in your network allows you to directly configure the relevant
parameters on the switches and routers rather than using a resource reservation
protocol.This section explains how to configure the managed switch to identify which traffic
class a packet belongs to, and how it should be handled to provide the quality of service you
want. As implemented on the managed switch, DiffServ allows you to control what traffic is
accepted and what traffic is discarded.
How you configure DiffServ support on the managed switch varies, depending on the role of
the switch in your network:
the switch in your network:
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Edge device. An edge device handles ingress traffic, flowing toward the core of the
network, and egress traffic, flowing away from the core. An edge device segregates
inbound traffic into a small set of traffic classes, and is responsible for determining a
packet’s classification. Classification is based primarily on the contents of the Layer 3 and
Layer 4 headers, and is recorded in the Differentiated Services Code Point (DSCP)
added to a packet’s IP header.
network, and egress traffic, flowing away from the core. An edge device segregates
inbound traffic into a small set of traffic classes, and is responsible for determining a
packet’s classification. Classification is based primarily on the contents of the Layer 3 and
Layer 4 headers, and is recorded in the Differentiated Services Code Point (DSCP)
added to a packet’s IP header.
•
Interior node. A switch in the core of the network is responsible for forwarding packets,
rather than for classifying them. It decodes the DSCP code point in an incoming packet,
and provides buffering and forwarding services using the appropriate queue
management algorithms.
rather than for classifying them. It decodes the DSCP code point in an incoming packet,
and provides buffering and forwarding services using the appropriate queue
management algorithms.
Before configuring DiffServ on a particular managed switch, you must determine the QoS
requirements for the network as a whole. The requirements are expressed in terms of rules,
which are used to classify inbound traffic on a particular interface. The switch software does
not support DiffServ in the outbound direction.
requirements for the network as a whole. The requirements are expressed in terms of rules,
which are used to classify inbound traffic on a particular interface. The switch software does
not support DiffServ in the outbound direction.
Rules are defined in terms of classes, policies, and services:
•
Class. A class consists of a set of rules that identify which packets belong to the class.
Inbound traffic is separated into traffic classes based on Layer 3 and Layer 4 header data
and the VLAN ID, and marked with a corresponding DSCP value. One type of class is
supported: All, which specifies that every match criterion defined for the class must be
true for a match to occur.
Inbound traffic is separated into traffic classes based on Layer 3 and Layer 4 header data
and the VLAN ID, and marked with a corresponding DSCP value. One type of class is
supported: All, which specifies that every match criterion defined for the class must be
true for a match to occur.
•
Policy. Defines the QoS attributes for one or more traffic classes. An example of an
attribute is the ability to mark a packet at ingress. The 7000 Series Managed Switch
supports a traffic conditions policy. This type of policy is associated with an inbound traffic
class and specifies the actions to be performed on packets meeting the class rules:
attribute is the ability to mark a packet at ingress. The 7000 Series Managed Switch
supports a traffic conditions policy. This type of policy is associated with an inbound traffic
class and specifies the actions to be performed on packets meeting the class rules:
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Marking the packet with a given DSCP code point, IP precedence, or CoS
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Policing packets by dropping or re-marking those that exceed the class’s assigned
data rate
data rate
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Counting the traffic within the class
•
Service. Assigns a policy to an interface for inbound traffic.