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 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:

If the Type parameter was set to Dynamic in Step 4, continue to Step 6.
If the Type parameter was set to Static in Step 4, go to Step 7.

Perform one of the following:

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.

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.

Repeat Step 4 as required to create additional candidate paths.

Click CREATE. The SR policy is created.

End of steps

Use subject to agreed restrictions on disclosure and use.