Traffic Shaping; Overview - D-Link DFL-1600 User Manual

23
Traffic Shaping
23.1

Overview

TCP/IP networks are being called upon to carry traffic belonging to a
growing variety of users with diverse service requirements, for example,
bulk data transfer, IP Telephony, VPNs, and multimedia applications. But
one of the major drawbacks of TCP/IP is the lack of true Quality of Service
(QoS) functionality, which is the ability to guarantee and limit bandwidth
for certain services and users. Although there are protocols like
Diff-Serv(Differentiated Services) and other solutions that intend to offer
QoS in large and complex networks, none of the solutions have reached a
high enough standard for large-scale usage.
Another fact is that most of the current QoS solutions are
application-based, that is, they work by having applications supplying the
network with QoS information. From a security standpoint, it is of course
unacceptable that the applications (that is, the users) decide the priority of
their own traffic within a network. In security-sensitive scenarios, where the
users cannot be trusted, the network equipment should be the sole arbiter
of priorities and bandwidth allocations.
To address the above problems, D-Link firewalls provide QoS functionality,
and apply limits and guarantees for QoS to the network traffic itself, rather
than trusting the applications/users to make the choices. It is hence well
suited to manage bandwidth for a small LAN as well as in one or more
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