How do I create an SR policy?

Purpose

SR policies can be manually created, or automatically generated. If, for example, the creation of a new LSP (with an Explicit Route Strategy of 'Standard BSID Preferred') causes the maximum stack depth (MSD) to be exceeded due to the number of strict hops through the network, NSP checks if an existing SR policy can be reused. If the existing policies are not sufficient, NSP will automatically generate a new SR policy using a backwards-recursive algorithm. SR Policies are preferred at domain boundaries.

This procedure is used to manually create an SR policy.

Note: Before creating an SR policy, the BGP of all eligible nodes must be configured to support sr-policy-ipv4 in family.

Note: Before creating an SR policy, open the sros-vm.conf file and ensure that it reads as follows:

sros-vms {

vms =[

{

rom=true

}

]

}

SR policies are imported into path simulation when importing a network from a file, or if 'Network and LSPs' is selected when importing a live network.

Note: Impacted SR policies are not included in the results of simulations or worst case failure scenarios.

Steps
 

Navigate to either the Path Control, SR Policies view or the Path Simulation, SR Policies view. A list of existing SR policies is displayed.


Click on the png5.png button. The Create SR policy form opens.


Configure the Policy parameters, as required:

Parameter

Description

Policy Name

Specifies the name of the SR policy

Description

Describes the SR policy

Color

Specifies the color to be associated with the SR policy. This parameter is required.

Headend

Specifies the IP address of a known router for the SR policy headend. This parameter is required.

Endpoint

Specifies the IP address of the SR policy endpoint. This parameter is required.

Administration

Specifies the administrative state of the SR policy


Configure the Candidate Path parameters, as required:

Parameter

Description

Candidate Path Name

Specifies the name of the candidate path

Distinguisher

Specifies the unique distinguisher in the context of BGP, when combined with endpoint and color. This parameter is required.

Description

Describes the candidate path

Administration

Specifies the administrative state of the candidate path

Type

Specifies the type of the candidate path; Dynamic or Static. This parameter is required.

Binding SID

Specifies the binding SID of the candidate path. This parameter is required.

Preference

Specifies preference of the candidate path when selecting the best candidate path for the SR policy. This parameter is required.

Bandwidth (Mbps)

Specifies the bandwidth capacity, in Mbps, of the candidate path (static only)

Note: If not manually specified, binding SIDs will only be generated if the label stack depth of the computed TE path exceeds the maximum stack depth requested or configured.

Note: The following REST API can be used to enable binding SID generation, and to configure binding SID and color range:

PATCH /sdn/api/v4/nsp/configuration/sr-policy-config

Where NSP_cluster is the IP address of the NSP cluster.

If the Binding SID parameter is manually configured with a value of -1, the binding SID will inherit configuration from the above REST API.

For more information, see the Network Developer Portal.

Note: When updating an SR policy, if a candidate path that is administratively 'Up' is modified - but remains administratively 'Up' - no changes to that candidate path will be processed.


Perform one of the following:

  1. If the Type parameter was set to Dynamic in Step 4, continue to Step 6.

  2. If the Type parameter was set to Static in Step 4, go to Step 7.


Perform one of the following:

  1. Using the Profile ID parameter, specify the identifier of a path profile policy to associate with the SR policy. The SR policy will automatically inherit the path profile policy's predefined constraints.

  2. Manually configure the constraint parameters, as required:

    Parameter

    Description

    Max Cost

    Specifies the maximum cost to consider

    Max Latency (microseconds)

    Specifies the maximum latency, in microseconds, to consider

    Max Hops (Span)

    Specifies the maximum number of hops to consider

    MSD

    Specifies the maximum SID depth to consider

    Max TE Metric

    Specifies the maximum TE metric to consider

    Include Any Bit Pos[0,..,31]

    Specifies any bit between 0 and 31 to include

    Exclude Any Bit Pos[0,..,31]

    Specifies any bit between 0 and 31 to exclude

    Include All Bit Pos[0,..,31]

    Specifies all bits between 0 and 31 for inclusion

Go to Step 10.


Click + SEGMENT LIST and configure the parameters:

Parameter

Description

Segment List Name

Specifies the name of the segment list

Weight

Specifies the segment list's weighted loadshare. Default weight is 1.


Click + SID and provide a unique identifier. Repeat as required.


Repeat Step 7 as required to create additional segment lists.


10 

Repeat Step 4 as required to create additional candidate paths.


11 

Click CREATE. The SR policy is created.

End of steps

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