Version 6.2  257  February 2011 
SIP User's Manual   3. Web-Based Management 
 
The router sends traffic as fast as it is received, while its well-designed QoS algorithms are 
left unused. Traffic shaping limits the bandwidth of the router, artificially forcing the router to 
be the bottleneck. A traffic shaper is essentially a regulated queue that accepts uneven 
and/or bursty flows of packets and transmits them in a steady, predictable stream so that 
the network is not overwhelmed with traffic. While Traffic Priority allows basic prioritization 
of packets, Traffic Shaping provides more sophisticated definitions, such as the following: 
  Bandwidth limit for each device 
  Bandwidth limit for classes of rules 
  Prioritization policy 
  TCP serialization on a device 
The bandwidth of a device can be divided to reserve constant portions of bandwidth to 
predefined traffic types. Such a portion is known as a Traffic Class. When not used by its 
predefined traffic type, or owner (for example VoIP), the bandwidth is available to all other 
traffic. However when needed, the entire class is reserved solely for its owner. Moreover, 
you can limit the maximum bandwidth that a class can use even if the entire bandwidth is 
available. When a shaping class is first defined for a specific traffic type, two shaping 
classes are created. The second class is the 'Default Class', which is responsible for all the 
packets that do not match the defined shaping class, or any other classes that may be 
defined on the device.  
¾  To configure traffic shaping: 
1.  Click the Traffic Shaping item (Configuration tab > Data menu > QoS submenu > 
Traffic Shaping); the following page appears: 
Figure  3-164: Configuring Traffic Shaping 
 
2.  Click the New Entry link; the following page appears. 
Figure  3-165: Adding Device for Traffic Shaping 
 
3.  From the 'Device' drop-down list, select the device ('Default WAN Device' or 'Default 
LAN Device') for which you want to shape the traffic. If you want to apply the settings 
on all LAN devices, select the 'Default LAN Device'.