H3C Technologies H3C WX6000 Series Access Controllers - Manual (Page 530)

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QoS Configuration
Support of the H3C WX series access controllers for line rate may vary by device model. Refer to
section "Feature Matrixes" in Compatibility Matrixes for details.
The sample output in this manual was created on the WX5004. The output on your device may
vary.
The grayed out functions or parameters on the Web interface indicate that they are not supported
or cannot be modified.
The models listed in this manual are not applicable to all regions. Please consult your local sales
office for the models applicable to your region.
Overview
QoS Overview
In data communications, Quality of Service (QoS) is the ability of a network to provide differentiated
service guarantees for diversified traffic regarding bandwidth, delay, jitter, and drop rate.
Network resources are always scarce. Wherever there is contention for resources, there is a demand
for QoS to prioritize important traffic flows over trivial traffic flows. When making a QoS scheme, a
network administrator must plan network resources carefully considering the characteristics of various
applications to balance the interests of diversified users and fully utilize network resources.
The following part introduces the QoS service models, and some mature QoS techniques in wide use.
Appropriately using these techniques in specific environments, you can improve QoS effectively.
Traditional packet forwarding services
On traditional IP networks, devices treat all packets equally and handle them using the first in first out
(FIFO) policy. All packets share the resources of the network and devices. How many resources the
packets can obtain completely depends on the time they arrive. This service is called best-effort. It
delivers packets to their destinations as possibly as it can, without any guarantee for delay, jitter, packet
loss ratio, reliability and so on.
This service policy is only suitable for applications insensitive to bandwidth and delay, such as WWW,
file transfer and e-mail.
New requirements from emerging applications
The Internet has been growing along with the fast development of networking technologies. More and
more users take the Internet as their data transmission platform to implement various applications.
Besides traditional applications such as WWW, e-mail and FTP, network users are experiencing new
services, such as tele-education, telemedicine, video telephone, videoconference and