1-11 QoS ConfigurationWhen configuring QoS, go to these sections for information you are interested in:z Overviewz QoS Features Supported by the S5100 Series Ethernet Switchesz Introduction to QoS Featuresz QoS Configurationz 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 focuses on improving services undercertain conditions rather than grading services precisely.In an internet, QoS evaluates the ability of the network to forward packets of differentservices. The evaluation can be based on different criteria because the network mayprovide various services. Generally, QoS refers to the ability to provide improved serviceby solving the core issues such as delay, jitter, and packet loss ratio in the packetforwarding process.Traditional Packet Forwarding ServicesOn traditional IP networks, devices treat all packets equally and handle them using the firstin first out (FIFO) policy. All packets share the resources of the network and devices. Howmany resources the packets can obtain completely depends on the time they arrive. Thisservice 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, suchas WWW, e-mail, and FTP.New Requirements from Emerging ApplicationsThe Internet has been growing along with the fast development of networking technologies.More and more people use the Internet to transmit data, share video and do a lot of otherthings.Besides traditional applications such as WWW, e-mail and FTP, network users areexperiencing new services, such as tele-education, telemedicine, video telephone,videoconference and Video-on-Demand (VoD). Enterprise users expect to connect their
