SNR S2989G-48TX-DC — настройка функций безопасности и QoS в сетевых устройствах [371/553]

S2989G-24TX Operation Manual

Chapter 6 Security Function Configuration

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This is acceptable for services like Mail and FTP, but for increasing multimedia business

data and e-business data transmission, this best effort method cannot satisfy the

bandwidth and low-lag requirement.

Based on differentiated service, QoS specifies a priority for each packet at the

ingress. The classification information is carried in Layer 3 IP packet header or Layer 2

802.1Q frame header. QoS provides same service to packets of the same priority, while

offers different operations for packets of different priority. QoS-enabled switch or router

can provide different bandwidth according to the packet classification information, and can

remark on the classification information according to the policing policies configured, and

may discard some low priority packets in case of bandwidth shortage.

If devices of each hop in a network support differentiated service, an end-to-end QoS

solution can be created. QoS configuration is flexible, the complexity or simplicity depends

on the network topology and devices and analysis to incoming/outgoing traffic.

6.12.1.3 Basic QoS Model

The basic QoS consists of four parts: Classification, Policing, Remark and Scheduling,

where classification, policing and remark are sequential ingress actions, and Queuing and

Scheduling are QoS egress actions.

Figure 6-37 Basic QoS Model

Classification: Classify traffic according to packet classification information and generate

internal priority based the classification information. For different packet types,

classification is performed differently; the flowchart below explains this in detail.