H3C S3600-28PSI System Description

Also see for S3600-28FEI: Datasheet Operation manual Operation manual

H3C S3600-28PSI System Description Manual pdf 68 page image

System DescriptionH3C S3600 Series Ethernet Switches Chapter 3 Software Features3-93.6 QoSQuality of service (QoS) provides differentiated network services to accommodate tovarious demands.3.6.1 Traffic ClassificationTraffic classification is to classify packets to facilitate the subsequent packet processingconducted by a switch.In traffic classification, a rule is specified for discriminating packets compliant with somecharacteristics. Classification rules can be very simple; for example, packets can besorted by the priority defined in the type of service (ToS) field in the IP header. They canalso be very complex; for example, packets can be sorted by any combination of MACaddress, IP protocol type, source (host or network) address, destination (host ornetwork) address, and even application port number, which involve the layers of datalink, network, and transport.3.6.2 Traffic Policing/Traffic AssuranceTraffic policing polices the traffic matching a traffic classification rule on the port wherethe packets are received, so that the traffic can effectively use the assigned networkresources such as bandwidth.Traffic policing mainly functions to limit the speed of an input port and thereby monitorthe traffic that enters its connected network. When packets arrive at the port at a speedexceeds the assigned bandwidth, they are either dropped or assigned a newpreference.Bandwidth assurance refers to assuring the minimum bandwidth for a special traffic sothat it can satisfy such QoS requirements as packet loss rate, delay, jitter even whennetwork congestion occurs.3.6.3 Port Flow ControlPort flow control is used for congestion management. Congestion occurs when thenetwork cannot reach the committed or negotiated performance specifications (such asspeed).When congestion occurs, the switch transmits a pause frame to the correspondingconnection and notifies the peer to pause for a period of time before transmitting dataagain, so as to reduce the incoming traffic on the network. The port control takes effecton all traffic.