Frame-based accounting

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

Overview

This feature when enabled allows 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.

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. Frame overhead is always accounted for on egress (queue rates and egress rate) and the user has no option to disable it.

Note:

  • The egress port rate limiter (ERL) calculation is also frame based, and the user has no option to disable it; ERL can be applied on the port to shape the egress rate.

  • On the 7210 SAS-Mxp, frame-based accounting for service meters is not supported.

  • Frame-based accounting for SAP egress aggregate meters is not supported on the 7210 SAS-T, 7210 SAS-Sx/S 1/10GE, 7210 SAS-Sx 10/100GE, and 7210 SAS-R6 and 7210 SAS-R12 in port scheduler mode.

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 may 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.

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.

Accounting and statistics

Accounting records and statistics do not account for frame overhead.

Basic configurations

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

  • The frame-based-accounting command is in the *A:Dut-1>config>qos>frame-based-accounting context.

  • The ingress-enable command enables frame-based-accounting for ingress metering.

  • The egress-enable command enables frame-based-accounting for egress queue rates, scheduler and port level egress-rate.

The following is a sample frame-based accounting configuration output.

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

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.

config>qos>frame-based-accounting

The following is a sample configuration output that shows 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 is a sample configuration output that shows 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#

Default frame-based accounting values

By default, the frame-based-accounting command is disabled for ingress.

By default, the frame-based-accounting command is disabled for egress. It is user-configurable and can be enabled or disabled.

Frame-based accounting command reference

Configuration commands

frame-based-accounting

Syntax

frame-based-accounting

Context

config>ops

Platforms

Supported on all 7210 SAS platforms as described in this document, including those operating in the access-uplink mode

Description

Commands in this context configure frame-based accounting.

egress-enable

Syntax

[no] egress-enable

Context

config>qos>frame-based-accounting

Platforms

Supported on all 7210 SAS platforms as described in this document, including those operating in the access-uplink mode

Description

This command enables the frame-based-accounting for access-egress, network-queue, port scheduler, SAP or Network Aggregate Rate and port-level egress-rate.

The no form of this command disables frame-based-accounting for all egress QoS.

Default

no egress-enable

ingress-enable

Syntax

[no] ingress-enable

Context

config>qos>frame-based-accounting

Platforms

Supported on all 7210 SAS platforms as described in this document, including those operating in the access-uplink mode

Description

This command enables the frame-based accounting for SAP-ingress and network QoS.

The no form of this command disables frame-based accounting for SAP-ingress and network QoS.

Default

no ingress-enable