QoS

Global Settings

There are two options for applying QoS information onto packets: the 802.1p Class of Service (CoS) priority field within the VLAN tag of tagged Ethernet frames, and Differentiated Services (DiffServ) Code Point (DSCP). Each port on the switch can be configured to trust one of the packet fields (802.1p , DSCP or DSCP+802.1p). Packets that enter the switch's port may carry no QoS information as well. If so, the switch places such information into the packets before transmitting them to the next node. Thus, QoS information is preserved between nodes within the network and the nodes know which label to give each packet. A trusted field must exist in the packet for the mapping table to be of any use. When a port is configured as untrusted, it does not trust any incoming packet priority designations and uses the port default priority value instead to process the packet.

Items	Descriptions
State	Select whether QoS is enabled or disabled on the switch.
Scheduling Method	Selects the Strict Priority or WRR to specify the traffic scheduling method. Strict Priority: Specifies traffic scheduling based strictly on the queue priority. WRR: Uses the Weighted Round-Robin (WRR) algorithm to handle packets in priority classes of service. It assigns WRR weights to queues.
Trust Mode	Select which packet fields to use for classifying packets entering the switch. DSCP: Classify traffic based on the DSCP (Differentiated Services Code Point) tag value. 802.1p: Classify traffic based on the 802.1p. The eight priority tags that are specified in IEEE 802.1p are from 1 to 8.

Click Apply to update the system settings.

CoS Mapping

Use the Class of Service (CoS) Mapping feature to specify which internal traffic class to map to the corresponding CoS value. CoS allows you to specify which data packets have greater precedence when traffic is buffered due to congestion.

Items	Descriptions
CoS	Displays the CoS priority tag values, where 0 is the lowest and 7 is the highest
Queue	Check the CoS priority tag box and select the Queue values for each CoS value in the provided fields. Eight traffic priority queues are supported, and the field values are from 1 to 8, where one is the lowest priority and eight is the highest priority.

Click the Apply button to accept the changes or the Cancel button to discard them.

DSCP Mapping

Use Differentiated Services Code Point (DSCP) Mapping feature to specify which internal traffic class to map to the corresponding DSCP values. DSCP Mapping increases the number of definable priority levels by reallocating bits of an IP packet for prioritization purposes.

Items	Descriptions
DSCP	Displays the packet's DSCP values, where 0 is the lowest and 10 is the highest.
Queue	Check the CoS priority tag box and select the Queue values for each DSCP in the provided fields. Eight traffic priority queues are supported, and the field values are from 1 to 8, where one is the lowest priority and eight is the highest priority.

Click the Apply button to accept the changes or the Cancel button to discard them.

Port Cos

From here, you can configure the QoS port settings for the switch. Select a port you wish to set and choose a CoS value from the drop-down box. Next, select to enable or disable the Trust setting to let any CoS packet be marked at ingress.

Port	Displays the ports for which the CoS parameters are defined.
CoS Value	Select the CoS priority tag values, where 0 is the lowest and 7 is the highest.
Trust	Select Enabled to trust any CoS packet marking at ingress. Select Disabled to not trust any CoS packet marking at ingress.

Click the Apply button to accept the changes or the Cancel button to discard them.

Bandwidth Control

The Bandwidth Control feature allows users to define the bandwidth settings for a specified port's Ingress Rate Limit and Egress Rate.

Items	Descriptions
Port	Displays the ports for which the bandwidth settings are displayed.
Ingress	Select enable or disable ingress on the interface.
Ingress Rate	Enter the ingress rate in kilobits per second. The gigabit Ethernet ports have a maximum speed of 1000000 kilobits per second.
Egress	Select from the drop-down box to Enable or Disable egress on the interface.
Egress Rate	Enter the egress rate in kilobits per second. The gigabit Ethernet ports have a maximum speed of 1000000 kilobits per second.

Click the Apply button to accept the changes or the Cancel button to discard them.

Storm Control

Storm Control limits the amount of Broadcast, Unknown Multicast, and Unknown Unicast frames accepted and forwarded by the switch. Storm Control can be enabled per port by defining the packet type and the rate that the packets are transmitted at. The switch measures the incoming Broadcast, Unknown Multicast, and Unknown Unicast frames rates separately on each port, and discards the frames when the rate exceeds a user-defined rate.

Items	Descriptions
Port	Displays the ports for which the Storm Control information is displayed.
Broadcast	Enter the broadcast rate in kilobits per second. The Gigabit Ethernet ports have a maximum speed of 1000000 kilobits per second. If the rate of broadcast traffic ingress on the interface increases beyond the configured threshold, the traffic is dropped.
Unknown Multicast	Enter the Unknown Multicast rate in kilobits per second. The gigabit Ethernet ports have a maximum speed of 1000000 kilobits per second. If the rate of broadcast traffic ingress on the interface increases beyond the configured threshold, the traffic is dropped.
Unknown Unicast	Enter the Unknown Unicast rate in kilobits per second. The gigabit Ethernet ports have a maximum speed of 1000000 kilobits per second. If the rate of broadcast traffic ingress on the interface increases beyond the configured threshold, the traffic is dropped.

Click the Apply button to accept the changes or the Cancel button to discard them.