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Create policies, Traffic conditioning policy – NETGEAR AV Line M4250 GSM4210PX 8-Port Gigabit PoE+ Compliant Managed AV Switch with SFP (220W) User Manual

Page 773

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Create policies

Use DiffServ policies to associate a collection of classes that you configure with one or
more QoS policy statements. The result of this association is referred to as a policy.

From a DiffServ perspective, there are two types of policies:

Traffic Conditioning Policy: A policy applied to a DiffServ traffic class

Service Provisioning Policy: A policy applied to a DiffServ service level

You must manually configure the various statements and rules used in the traffic
conditioning and service provisioning policies to achieve the desired Traffic Conditioning
Specification (TCS) and the Service Level Specification (SLS) operation, respectively.

Traffic conditioning policy

Traffic conditioning pertains to actions performed on

incoming traffic. Several distinct QoS actions are associated with traffic conditioning:

Dropping: Drop a packet upon arrival. This is useful for emulating access control
list operation using DiffServ, especially when DiffServ and ACL cannot coexist on
the same interface.

Marking IP DSCP or IP precedence: Marking/re-marking the DiffServ code point
in a packet with the DSCP value representing the service level associated with a
particular DiffServ traffic class. Alternatively, the IP Precedence value of the packet
can be marked/re-marked.

Marking CoS (802.1p): Sets the three-bit priority field in the first/only 802.1p header
to a specified value when packets are transmitted for the traffic class. An 802.1p
header is inserted if it does not already exist. This is useful for assigning a Layer 2
priority level based on a DiffServ forwarding class (such as the DSCP or IP precedence
value) definition to convey some QoS characteristics to downstream switches that
do not routinely look at the DSCP value in the IP header.

Policing: A method of constraining incoming traffic associated with a particular class
so that it conforms to the terms of the TCS. Special treatment can be applied to
out-of-profile packets that are either in excess of the conformance specification or
are non-conformant.
The DiffServ feature supports the following types of traffic policing treatments
(actions):

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drop: The packet is dropped

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mark cos: The 802.1p user priority bits are (re)marked and forwarded

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mark dscp: The packet DSCP is (re)marked and forwarded

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mark prec: The packet IP Precedence is (re)marked and forwarded

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send: the packet is forwarded without DiffServ modification

Main User Manual

773

Configuration Examples

AV Line of Fully Managed Switches M4250 Series Main User Manual