5. Frame-based Accounting

This chapter provides information to configure frame-based accounting using the command line interface.

5.1. Overview

This feature when enabled let QoS policies to account for the Ethernet frame overhead (for example, it accounts for the IFG (inter-frame gap) and the preamble). Typically, the IFG and preamble constitutes about 12 + 8 = 20 bytes. The overhead for Ethernet ports uses this value.

5.1.1. Frame-based Accounting

A configurable CLI command enables accounting of the frame overhead at ingress or egress. This is a system wide parameter and affects the behavior of the ingress meter or egress rate. When disabled, the queue rates and egress-rate do not account for the Ethernet frame overhead. By default frame-based accounting is disabled for both ingress and egress.

Note:

  1. On the 7210 SAS-Mxp, frame-based accounting for service meters is not supported.
  2. Frame-based accounting for SAP egress aggregate meters is not supported on the 7210 SAS-M, 7210 SAS-T, 7210 SAS-Sx/S 1/10GE, and 7210 SAS-Sx 10/100GE.

5.1.2. Effects of Enabling Ingress Frame-based Accounting on Ingress Meter Functionality

To enable system-wide consistency in configuring QoS queue and meter rate parameters, the meters used on the system ingress might need to account for Ethernet frame overhead. Network ingress and service ingress meters account for Ethernet frame overhead. A configurable CLI command can enable or disable the frame overhead accounting. This is a system-wide parameter affecting the behavior of all the meters in the system.

5.1.3. Effects of Enabling Egress Frame-based Accounting on Network Queue Functionality

If frame overhead consideration is enabled, then queue scheduler accounts for the Ethernet frame overhead. The maximum egress bandwidth accounts for the Ethernet frame overhead (it accounts for the IFG (inter-frame gap) and the preamble). Typically, the IFG and preamble constitutes about 12 + 8 = 20 bytes. The overhead for Ethernet ports uses this value.

A configurable CLI command enables accounting of the frame overhead. This is a system wide parameter and affects the behavior of all egress queues (when frame-based-accounting is enabled on egress port (network ports or access-uplink ports, as applicable), the associated queues also account for frame overhead implicitly). When disabled, the egress-rate command does not account for the Ethernet frame overhead.

5.1.4. Accounting and Statistics

Accounting records and statistics do not account for frame overhead.

5.2. Basic Configurations

To enable frame-based accounting, you must perform the following:

  1. The frame-based-accounting command is in the *A:Dut-1> config>qos>frame-based-accounting context.
  2. The ingress-enable command enables frame-based-accounting for ingress metering.
  3. The egress-enable command enables frame-based-accounting for egress queue rates, scheduler and port level egress-rate.

The following displays the frame-based accounting configuration:

*A:Dut-1>config>qos>frame-based-accounting# info detail 
----------------------------------------------
            no ingress-enable
            no egress-enable
----------------------------------------------
*A:Dut-1>config>qos>frame-based-accounting#

5.2.1. Enabling and Disabling Frame-Based Accounting

To enable frame-based-accounting for ingress, you can simply use the ingress-enable command and to enable frame-based-accounting on egress use the egress-enable command. To disable frame-based-accounting for ingress, execute the no ingress-enable command and to disable frame-based-accounting on egress, execute the no egress-enable command.

CLI Syntax:
config>qos>frame-based-accounting

The following output displays the enabling of frame-based-accounting:

*A:Dut-1>config>qos>frame-based-accounting# ingress-enable 
*A:Dut-1>config>qos>frame-based-accounting# egress-enable 
*A:Dut-1>config>qos>frame-based-accounting# info 
----------------------------------------------
            ingress-enable
            egress-enable
----------------------------------------------
*A:Dut-1>config>qos>frame-based-accounting#

The following output displays the disabling of frame-based-accounting:

*A:Dut-1>config>qos>frame-based-accounting# no ingress-enable 
*A:Dut-1>config>qos>frame-based-accounting# no egress-enable 
*A:Dut-1>config>qos>frame-based-accounting# info detail 
----------------------------------------------
            no ingress-enable
            no egress-enable
----------------------------------------------
*A:Dut-1>config>qos>frame-based-accounting#