The metric-delay advertisement enable command enables the advertisement of IPv4 delay information.
The undo metric-delay advertisement enable command restores the default configuration.
By default, the advertisement of IPv4 delay information is disabled.
Usage Scenario
Traditional path computation algorithms compute the optimal path to a destination address based on costs. However, such a computed path may not have the minimum delay. For services that have stringent requirements on delay, path computation can be performed based on delay instead of costs to ensure that service traffic is transmitted along the path with the minimum delay. To meet these requirements, run the metric-delay advertisement enable command to enable the advertisement of IPv4 delay information for an IS-IS process. After this function is enabled, IS-IS collects and floods information about the intra-area IPv4 link delay, and BGP-LS reports the information to the controller. This allows the controller to use the delay information to compute the optimal path on the P2P network. Delays in controlled include dynamic monitoring delay and static configuration delay.
Prerequisites
The cost type for the IS-IS routes that a device can send and accept has been set to wide, wide-compatible, or compatible using the cost-style command. In addition, TE has been enabled for an IS-IS process using the traffic-eng command.
Precautions
The published delay can be a dynamic delay measured by TWAMP light or a configured static delay.
For dynamic delay, an IS-IS interface bound to a TWAMP Light session, delay information can be advertised to this interface only when the TWAMP Light session detects valid statistics. Upon receipt, IS-IS advertises and floods the delay information.