Dell Force10 MXL Blade MXL 10/40GbE Switch IO Module Configuration Guide - Page 432

www.dell.com | support.dell.com Apply an Output Policy Map to an Interface To apply an output policy map to an interface, use the service-policy output command from INTERFACE mode. You can apply the same policy map to multiple interfaces, and you can modify a policy map after you apply it. QoS Rate Adjustment The Ethernet packet format consists of: • Preamble: 7-bytes Preamble • Start Frame Delimiter (SFD): 1 byte • Destination MAC Address: 6 bytes • Source MAC Address: 6 bytes • Ethernet Type/Length: 2 bytes • Payload: (variable) • Cyclic Redundancy Check (CRC): 4 bytes • Inter-frame Gap (IFG): (variable) By default, for rate policing and shaping, FTOS does not include the Preamble, SFD, or the IFG fields. These fields are overhead; only the fields from MAC Destination Address to the CRC are used for forwarding and are included in these rate metering calculations. You can optionally include overhead fields in rate metering calculations by enabling QoS Rate Adjustment. QoS rate adjustment is disabled by default with the no qos-rate-adjust parameter listed in the running-configuration. Task Command Syntax Include a specified number of bytes of packet overhead to include in rate policing and shaping calculations. For example, to include the Preamble and SFD, enter qos-rate-adjust 8. For variable length overhead fields, you must know the number of bytes you want to include. qos-rate-adjust overhead-bytes Default: Disabled Range: 1-31 Command Mode CONFIGURATION 430 | Quality of Service (QoS)