3Com 4007, Implementation Manual, Page: 567 / 684

QoS Overview 567
Benefits You can use QoS on your Multilayer Switching Module to provide the
following benefits:
■
Control a wide variety of Ethernet network traffic by:
■
Classifying traffic based on packet attributes such as protocol type,
class type (802.1p), IP address, or TCP/UDP socket
■
Assigning priorities to traffic (for example, to set higher priorities
for time-critical or business-critical applications)
■
Applying security policy through traffic filtering
■
Using the connection-oriented RSVP for bandwidth reservation
(reserving and policing an RSVP session to make sure the session
uses only as much bandwidth as it needs)
■
Provide constant delay control and jitter control for multimedia
applications such as video conferencing or voice over IP
■
Improve performance for specific types of traffic and preserve
performance as the volume of traffic grows
■
Reduce the need to constantly add bandwidth to the network
■
Manage network congestion
Methods of Using
QoS
Your Multilayer Switching Module’s implementation of QoS focuses on
traffic classification, policy-based management, and bandwidth. It
provides multiple service levels (mapped to several transmit queues),
classification of traffic types, and weighted fair queueing of
priority-queued traffic.
If you use QoS and decide to classify traffic broadly, you are using a
subset of QoS called
network class of service . To simplify your
classification of traffic, the Multilayer Switching Module provides a set of
predefined traffic classes. You can also specify your own classes of traffic
with applied controls to:
■
Create a to/from classifier with address/port patterns that isolate
traffic based on source and destination.
■
Block traffic (for example, prevent certain traffic from one workgroup
from seeing another workgroup).
■
Assign priorities to traffic.
See “Examples of Classifiers and Controls” later in this chapter.