Technical information

Watson SHDSL Router
Web-based Management Manual
Watson-SHDSL-Router-GUI-Manual.doc
Version 2.3-03
8-44
Revision: 2012-02-29
 Apply QoS on Select whether to apply QoS on a connection or just
the first packet. When applying on a connection, the data transfer session will
be handled using Stateful Packet Inspection (SPI). This means that other
packets matching this rule will be automatically allowed to access, and the
same QoS scheme will be applied to them.
Logging Monitor the rule.
 Log Packets Matched by This Rule Select this check box to log the first
packet from a connection that was matched by this rule.
Schedule By default, the rule will always be active. However, you can configure
scheduler rules by selecting 'User Defined', in order to define time segments during
which the rule may be active. To learn how to configure scheduler rules, refer to
Section 9.9.3.
3. Click 'OK' to save the settings.
The order of the rules' appearance represents both the order in which they were
defined and the sequence by which they will be applied. You may change this order
after your rules are already defined (without having to delete and then re-add
them), by using the action icon and action icon .
8.3.4 Traffic Shaping
Traffic Shaping is the solution for managing and avoiding congestion where a high
speed LAN meets limited broadband bandwidth. A user may have, for example, a
100 Mbps Ethernet LAN with a 100 Mbps WAN interface router. The router may
communicate with the ISP using a modem with a bandwidth of 2Mbps. This typical
configuration makes the modem, having no QoS module, the bottleneck.
The router sends traffic as fast as it is received, while its well-designed QoS algo-
rithms 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 are:
 Bandwidth limit for each device
 Bandwidth limit for classes of rules
 Prioritization policy
 TCP serialization on a device
Additionally, you can define QoS traffic shaping rules for a default device. These
rules will be used on a device that has no definitions of its own. This enables the
definition of QoS rules on Default WAN, for example, and their maintenance even if
the PPP or bridge device over the WAN is removed.
8.3.4.1 Traffic Classes
The bandwidth of a device can be divided in order 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