This window lets you create a class of service (CoS) that includes one or more of the following components: an 802.1p priority, an IP type of service (ToS) value, rate limits, and transmit queue configuration. Once you've created the class of service, you can apply it as a classification rule action, as part of the definition of an automated service, or as a role default. For more information, see Getting Started with Class of Service.
To access this window, open the Class of Service Configuration Window (available from the Policy Manager Edit menu). Then, click the Create button and select Create Class of Service from the menu.
Click the graphic for more information.
General
- 802.1p Priority
- If the class of service includes an 802.1p priority, select this checkbox and use the drop-down list to choose the priority (0-7 with 7 being the highest priority).
- ToS/DSCP Marking
- Some IP rules allow a ToS/DSCP value to be
written to the ToS/DSCP field in the IP header of incoming packets.
Select this option to associate an IP ToS (Type of
Service) or DSCP (Diffserv Codepoint) rewrite value with this class of
service. See
ToS/DSCP Rewrite and
ToS/DSCP Value Definition Chart for more information.
- Value - The IP type of service value is an 8-bit hexadecimal number between 0 and FF (see IP Type of Service for more information). You can either enter this value in the Value 0x text box, or click Select to open the ToS/DSCP Configuration window, where you can automatically configure a ToS (Type of Service) or DSCP (Diffserv Codepoint) value.
- Mask - The ToS mask controls which bits in the ToS/DSCP field of incoming packets will be overwritten. Masking a ToS value is only supported on K-Series, S-Series and N-Series devices. Devices that do not support the mask will ignore this field.
| NOTE: | If you apply a class of service with a ToS/DSCP value as a role default, the ToS/DSCP value will be ignored. This
is because ToS/DSCP rewrite works
only for certain IP ToS classification rules, not as a role default. |
|---|
- Drop Precedence
- The Drop Precedence option is used in conjunction with the Flex-Edge feature available on K-Series and S-Series (Release 7.11 or higher) devices. Flex-Edge provides the unique capability to prioritize traffic in the MAC chip as it enters the switch. When the Class of Service is assigned to a policy role, and that role is applied to a port via a MAC source address mapping or the port default role, the drop precedence will dictate the internal priority (within the MAC chip) that will be used for packets received on the port. If congestion occurs, packets with a high drop precedence are discarded first. Therefore, if a packet is important, it should have a low drop precedence. Refer to the K-Series or S-Series Configuration Guide for more information on the Flex-Edge feature and drop precedence.
- Transmit Queue
- Use the drop-down menu to select a transmit queue for the class of service. If you would like to select a different transmit queue for each port type, select the "Q/Port Type" option. Then, when you click Apply or OK, you will see a window where you can specify a different transmit queue for each port type.
Rate Limit Configuration
This section lets you select the port inbound and outbound rate limit to associate with the class of service.
Rate limits are used to control the transmit rate at which traffic enters and exits ports in your network. All traffic mapped to this Class of Service on a given port will share the bandwidth specified by the rate limit.
In addition, if you have ExtremeWireless Wireless Controllers (Release 8.01.xx or higher) on your network, you will see an option to configure inbound and outbound user rate limits. User rate limits specify the bandwidth given to each individual user on a port. Currently, user rate limits are only available for these wireless controllers.
- Inbound/Outbound Rate Limit
- Use the drop-down list to select or create the port inbound/outbound rate limit to associate with the class of service.
- Inbound/Outbound User Rate Limit
- Use the drop-down list to select or create the user inbound/outbound rate limit to associate with the class of service.
For information on related concepts:
For information on related tasks: