metric-delay suppress timer

Function

The metric-delay suppress timer command configures suppression parameters for IPv4 delay information advertisement.

The undo metric-delay suppress timer command restores the default configuration.

By default, the suppression of IPv4 delay information advertisement is enabled.

Format

metric-delay suppress timer time-value percent-threshold percent-value absolute-threshold absolute-value

undo metric-delay suppress timer time-value percent-threshold percent-value absolute-threshold absolute-value

Parameters

Parameter	Description	Value
time-value	Specifies a timeout period for the delay suppression timer.	The value is an integer ranging from 0 to 600, in seconds. The default value is 120. The value 0 indicates that the delay suppression timer is not started.
percent-threshold percent-value	Specifies a threshold over which delay information advertisement is suppressed.	The value is an integer ranging from 0 to 100, in percentage. The default value is 10. The value 0 indicates that delay information advertisement is not suppressed based on this parameter.
absolute-threshold absolute-value	Specifies an absolute value threshold over which delay information advertisement is suppressed.	The value is an integer ranging from 0 to 10000, in microseconds. The default value is 1000.The value 0 indicates that delay information advertisement is not suppressed based on this parameter.

Parameter

Description

Value

time-value

Specifies a timeout period for the delay suppression timer.

The value is an integer ranging from 0 to 600, in seconds. The default value is 120.

The value 0 indicates that the delay suppression timer is not started.

percent-threshold percent-value

Specifies a threshold over which delay information advertisement is suppressed.

The value is an integer ranging from 0 to 100, in percentage. The default value is 10. The value 0 indicates that delay information advertisement is not suppressed based on this parameter.

absolute-threshold absolute-value

Specifies an absolute value threshold over which delay information advertisement is suppressed.

The value is an integer ranging from 0 to 10000, in microseconds. The default value is 1000.The value 0 indicates that delay information advertisement is not suppressed based on this parameter.

Views

IS-IS view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
isis	write

Usage Guidelines

Usage Scenario

If delay variation occurs frequently, link delay information is flooded and reported repeatedly, causing the optimal path calculated by a controller based on delay information to change frequently. To prevent this issue, run the metric-delay suppress timer command to suppress the advertisement of IPv4 delay information. Suppression is performed in compliance with the following rules:

If a delay change is detected, the delay information is not immediately advertised or reported. Instead, the maximum and minimum delays are recorded within the suppression timer specified using timer-value. When the timer expires, IS-IS starts to suppress the advertisement of delay information.
If the calculated percentage threshold is greater than or equal to the percentage threshold specified using percent-value, and the calculated absolute threshold is greater than or equal to the absolute threshold specified using absolute-value, then IS-IS updates the delay information accordingly and uses BGP-LS to report the new delay information to the controller. Otherwise, IS-IS does not perform the update and suppresses the advertisement of the delay information instead.

Precautions

If the values of timer-value, percent-value, and absolute-value are all set to 0 on a device, the device is disabled from suppressing the advertisement of delay information.

If IPv4 delay information advertisement enabled using the metric-delay advertisement enable command does not take effect, the metric-delay suppress timer command cannot be run.

It is recommended that the value specified by timer-value be greater than the interval at which sampled TWAMP data is sent to IS-IS.

Example

# Enable suppression of IPv4 delay information advertisement for IS-IS Level-2 routes.

<HUAWEI> system-view
[~HUAWEI] isis 1
[*HUAWEI-isis-1] cost-style wide
[*HUAWEI-isis-1] traffic-eng level-2
[*HUAWEI-isis-1] metric-delay advertisement enable level-2
[*HUAWEI-isis-1] metric-delay suppress timer 300 percent-threshold 20 absolute-threshold 2000