LevelOne GSW-2476 user manual 5-33, QOS Settings, QoS Disabled, 802.1p, Dscp

WEB CONFIGURATION

QOS Settings

QoS (Quality of Service) is a mechanism that is used to prioritize certain traffic as it is forward through the switch. Traffic can be classified as High or Normal priority and, when the switch is heavily loaded, it is the Normal priority packets that are dropped first. You can select how traffic is prioritized by using one of the three QoS modes, which are selected using the QoS Mode drop-down list.

Note: Only one QoS mode can be active at one time. It is not possible, for example, to prioritize traffic using the DSCP value and 802.1p tag.

QoS Disabled

QoS is turned off and all packets have equal priority.

802.1p

Packets are prioritzed using the content of the VLAN-tag. The 802.1p field is held within the VLAN-tag of a packet. The field is three bits long so can hold eight values; 0 - 7 inclusive. When QoS Mode is set to 802.1p, the 802.1p Configuration table appears which allows a priority (normal or high) to be set for each of the eight values.

You can use the Prioritize Traffic drop-down list to quickly set the values in the 802.1p Configuration table. Select All Normal Priority to set all values to normal priority or select All High Priority to set all values to high priority. Use Custom if you want to set each value individually.

Note: Because end-stations, like PCs, are not usually VLAN aware, they do not create VLAN-tagged frames. As a result, this method of prioritization is not ideal when there are a lot of PCs connected to the switch.

DSCP

Packets are prioritized using the DSCP (Differentiated Services Code Point) value.

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