Upvel UP-316FEW — configure QoS Priority Modes and CoS Settings for Packet Prioritization [31/52]

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UP-308FEW / UP-316FEW

QoS Setting

Here you can configure QoS priority mode and CoS (Class of Service). QoS (Quality of

Service) refers to mechanisms in the network software that make the actual determination of

which packets have priority. CoS refers to feature sets, or groups of services, that are

assigned to users based on company policy. If a feature set includes priority transmission,

then CoS winds up being implemented in QoS functions within the routers and switches in

the network. In an enterprise network, class of service (CoS) differentiates high-priority traffic

from low-priority traffic. Tags may be added to the packets to identify such classes, but they

do not guarantee delivery as do quality of service (QoS) functions, which are implemented in

the network devices.

Priority mode

There are three priority modes available to specify the priority of packets being serviced.

Those include First-In-First-Out, All-High-Before-Low (Strict Priority) and 4 Queue

Weighted Round Robin.

• First-In-First-Out: Packets are queued and serviced in the order they were received.

• All-High-Before-Low (Strict priority): All packets will be assigned to either high priority

queue (Queue 2) or low priority queue (Queue 1). The packet in the low priority queue will

not be forwarded until the high priority queue is empty.

• 4 Queue WRR: There are 4 priority queues for Weighted-Round-Robin (WRR) mode.

Q3 and Q4 are Low-weight queues (weight range: 0~8), Q1 and Q2 are High-weight

queues (weight range: 0~8).

In this mode, the switch will forward a specified number of high priority packets and then a

specified number of low priority packets. The switch repeats this cycle continuously.

Terms "low weight" and "high weight" mean the ratio of the packet in the transmit queue.

For example, if "low weight" and "high weight" are set to "3" and "5", the ratio of the

transmit packet for the low priority to high priority is 3/5.

When the queue weight is set to 0, it will be treated as 8.

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