Nokia IP60 - Security Appliance, User Manual

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Overview
Chapter 9: Using Traffic Shaper 181
Chapter 9
This chapter describes how to use Traffic Shaper to control the flow of communication to and from your
network.
This chapter includes the following topics:
Overview .................................................................................................. 181
Setting Up Traffic Shaper ......................................................................... 182
Predefined QoS Classes ............................................................................ 182
Adding and Editing Classes ...................................................................... 184
Viewing and Deleting Classes .................................................................. 187
Restoring Traffic Shaper Defaults ............................................................ 187
Overview
Traffic Shaper is a bandwidth management solution that allows you to set bandwidth policies to control the
flow of communication. Traffic Shaper ensures that important traffic takes precedence over less important
traffic, so that your business can continue to function with minimum disruption, despite network
congestion.
Traffic Shaper uses Stateful Inspection technology to access and analyze data derived from all
communication layers. This data is used to classify traffic in up to eight user-defined Quality of Service
(QoS) classes. Traffic Shaper divides available bandwidth among the classes according to weight. For
example, suppose Web traffic is deemed three times as important as FTP traffic, and these services are
assigned weights of 30 and 10 respectively. If the lines are congested, Traffic Shaper will maintain the ratio
of bandwidth allocated to Web traffic and FTP traffic at 3:1.
If a specific class is not using all of its bandwidth, the leftover bandwidth is divided among the remaining
classes, in accordance with their relative weights. In the example above, if only one Web and one FTP
connection are active and they are competing, the Web connection will receive 75% (30/40) of the leftover
bandwidth, and the FTP connection will receive 25% (10/40) of the leftover bandwidth. If the Web
connection closes, the FTP connection will receive 100% of the bandwidth.
Traffic Shaper allows you to give a class a bandwidth limit. A class's bandwidth limit is the maximum
amount of bandwidth that connections belonging to that class may use together. Once a class has reached
its bandwidth limit, connections belonging to that class will not be allocated further bandwidth, even if
there is unused bandwidth available. For example, you can limit all traffic used by Peer-To-Peer file-
sharing applications to a specific rate, such as 512 kilobit per second. Traffic Shaper also allows you to
assign a ―Delay Sensitivity‖ value to a class, indicating whether connections belonging to the class should
be given precedence over connections belonging to other classes.
Traffic Shaper supports DiffServ (Differentiated Services) Packet Marking. DiffServ marks packets as
belonging to a certain Quality of Service class. These packets are then granted priority on the public
network according to their class.
Using Traffic Shaper