Reroute LSPs
Routing Director uses Path Computation Element Protocol (PCEP) or Network Configuration Protocol (NETCONF) to learn and discover Label-switched Paths (LSPs) in your network.
Routing Director can automatically reroute LSP based on the following predefined parameters that you set at your organization level:
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Equal-cost multipath (ECMP) placement method—Routing Director adopts ECMP-based rerouting of LSPs to load balance traffic and increase bandwidth by fully utilizing unused bandwidth on links to the same destination.
You need to set the ECMP Placement Method parameter. Based on the placement method you select (Random, Least-Filled, and Most-Filled), Routing Director evaluates link metrics, and if there are multiple ECMP path available towards the same destination then Routing Director selects a path based on the user settings.
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Link utilization threshold—Routing Director automatically reroutes LSP when the utilization of a link exceeds a specified threshold, ensuring optimal network performance and preventing congestion. For automatic rerouting of LSPs, you need to set Link Utilization Threshold, Threshold Rerouting Interval, Link Utilization Violation Interval, and Link Utilization Violation Count parameters.
If both Threshold Rerouting Interval and the violation counts are set then Threshold Rerouting Interval has no effect.
Note:Besides organization-level settings, you can also set the link utilization threshold at the link level. The link-level setting overrides the organization level settings.
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Path optimization interval—Routing Director ensures LSPs are routed through the most optimal paths. Even if an LSP is rerouted due to threshold crossing, link failure or topology change, the LSP should return to its optimal path once the congestion is resolved. For Routing Director to reroute LSPs through the most optimal paths, you need to set the Path Optimization Interval parameter.
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Link Utilization Violation—Routing Director automatically reroutes LSP when the link utilization violation occurs for a specific time duration and count. For automatic rerouting of LSPs, you need to set Link Utilization Violation Interval and Link Utilization Violation Count parameters.
This mechanism prevents unnecessary rerouting due to transient issues, therefore ensuring that only consistent violations lead to rerouting.
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Tunnel Delay Violation—Routing Director automatically reroutes an LSP with maximum delay value configured, when the tunnel delay violation occurs for a specific time duration and count. For automatic rerouting of LSPs, you need to set Tunnel Delay Violation Interval and Tunnel Delay Violation Count parameters.
This mechanism prevents unnecessary rerouting due to transient issues, therefore ensuring that only consistent violations lead to rerouting.
Note:If the specified Tunnel Delay Violation Interval is lesser than the LSP Latency Interval (default value is 5 minutes), then the threshold maximum delay rerouting will not happen.
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Interface Delay Type—Routing director uses delay information from interfaces connected to links and computes the best path for LSPs that are configured with Delay as Routing Method.
Use the Interface Delay Type field on the Pathfinder Settings section of the Organization Settings page (Settings Menu > System Settings) to choose one of the following for computing path delay: minimum, maximum, or average. The option you choose is applied to the entire topology and is not specific to a link or an interface.
Routing Director learns about the delay on links from devices on which delay measurement is enabled through BGP-LS. The information received by the device contains maximum, minimum, and average delay values obtained during a measurement period. Based on the option you have chosen for Interface Delay Type (minimum, maximum, or average), Routing Director uses that delay value and computes the best path for LSPs.
To configure the parameters at your organization level: