1-11 QoS ConfigurationWhen configuring QoS, go to these sections for information you are interested in:z Overviewz QoS Supported by the S5600 Series Ethernet Switchesz QoS Configurationz Displaying and Maintaining QoSz QoS Configuration ExamplesOverviewIntroduction to QoSQuality of Service (QoS) is a concept concerning service demand and supply. It reflects theability to meet customer needs. Generally, QoS does not focus on grading servicesprecisely, but on improving services under certain conditions.In an internet, QoS refers to the ability of the network to forward packets. The evaluationon QoS of a network can be based on different aspects because the network may providevarious services. Generally, QoS refers to the ability to provide improved service bysolving the core issues such as delay, jitter, and packet loss ratio in the packet forwardingprocess.Traditional Packet Forwarding ServiceIn 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 forwardingis determined by the order in which packets arrive. All the packets share the resources ofthe network. Network resources available to the packets completely depend on the timethey arrive. This service policy is known as Best-effort, which delivers the packets to theirdestination 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 tobandwidth and delay, such as WWW, E-mail and FTP.New Applications and New RequirementsWith the expansion of computer network, more and more networks become part of theInternet. The Internet gains rapid development in terms of scale, coverage and userquantities. More and more users use the Internet as a platform for their services and fordata transmission.Besides the traditional applications such as WWW, E-mail, and FTP, new services aredeveloped on the Internet, such as tele-education, telemedicine, video telephone,videoconference and Video-on-Demand (VoD). Enterprise users expect to connect their
