Traditional Packet Forwarding Service; New Applications And New Requirements - H3C S3100-52P Operation Manual

Operation Manual – QoS-QoS Profile
H3C S3100-52P Ethernet Switch

1.1.2 Traditional Packet Forwarding Service

In traditional IP networks, packets are treated equally. That is, the FIFO (first in first out)
policy is adopted for packet processing. Network resources required for packet
forwarding is determined by the order in which packets arrive. All the packets share the
resources of the network. Network resources available to the packets completely
depend on the time they arrive. This service policy is known as Best-effort, which
delivers the packets to their destination with the best effort, with no assurance and
guarantee for delivery delay, jitter, packet loss ratio, reliability, and so on.
The traditional Best-Effort service policy is only suitable for applications insensitive to
bandwidth and delay, such as WWW, E-mail and FTP.

1.1.3 New Applications and New Requirements

With the expansion of computer network, more and more networks become part of the
Internet. The Internet gains rapid development in terms of scale, coverage and user
quantities. More and more users use the Internet as a platform for their services and for
data transmission.
Besides the traditional applications such as WWW, E-mail, and FTP, new services are
developed on the Internet, such as tele-education, telemedicine, video telephone,
videoconference and Video-on-Demand (VoD). Enterprise users expect to connect
their regional branches together using VPN techniques for coping with daily business,
for instance, accessing databases or manage remote equipments through Telnet.
All these new applications have one thing in common, that is, they have special
requirements for bandwidth, delay, and jitter. For instance, bandwidth, delay, and jitter
are critical for videoconference and VoD. As for other applications, such as transaction
processing and Telnet, although bandwidth is not as critical, a too long delay may cause
unexpected results. That is, they need to get serviced in time even if congestion occurs.
Newly emerging applications demand higher service performance from IP networks. In
addition to simply delivering packets to their destinations, better network services are
demanded, such as allocating dedicated bandwidth, reducing packet loss ratio,
avoiding congestion, regulating network traffic, and setting priority of the packets. To
meet those requirements, the network should be provided with better service capability.
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Chapter 1 QoS Configuration