What is QoS? (quality of service)

see unicast 、 radio broadcast 、 The differences and characteristics of multicast When , notice QOS I don't know what it means

QoS（Quality of Service, Service quality ） It means that a network can utilize various basic technologies , Provide better service capability for specified network communication , It's a kind of network security mechanism , It's a technology to solve the problems of network delay and blocking .QoS It's very important for a network with limited capacity , Especially for streaming multimedia applications , for example VoIP and IPTV etc. , Because these applications often need a fixed transmission rate , It is also sensitive to delay .

Definition

When the network is congested , All data streams may be discarded ; In order to meet the requirements of users for different applications and different service quality , It requires that the network can allocate and schedule resources according to the requirements of users , Provide different quality of service for different data streams ： Give priority to the processing of real-time and important data messages ; For ordinary data messages with weak real-time performance , Provide lower processing priority , Even discard when the network is congested .QoS emerge as the times require . Support QoS Functional devices , It can provide transmission quality service ; For a certain kind of data flow , Can be for it Assign a certain level of transmission priority , To identify its relative importance , And use various priority forwarding strategies provided by the device 、 Congestion avoidance and other mechanisms provide special transmission services for these data streams . Configured with QoS Network environment , Increase the predictability of network performance , And can effectively allocate network bandwidth , Make more rational use of network resources .

Reference article ：qos