How do I collect bit rate statistics using 7250 IXR?

Purpose

NSP can use Flow Collectors to collect and process 7250 IXR gen 1 bit rate telemetry over SR-TE and RSVP-TE LSP hops. Bit rate is calculated on LSPs for transit routers only at the next-hop ingress, and not on edge or head-end routers. The BR statistics are viewable in Path Control, LSPs in the Bandwidth column.

The following limitations affect this use case:

Flow collection must be configured and running in the NSP deployment.
Strict hop adjacency SID LSPs only (RRO must be only ADJ-SIDs). Supports SR-TE policies.
Only Adjacency SIDs and Binding SIDs are supported in the LSP Path. The use of Node SIDs is not supported. The Explicit Route Strategy of Compressed can not be used for LSP Paths originating on a 7250 IXR gen 1 that require statistics collection.
Parallel LSP paths cannot have their bandwidth determined, they must either be set to zero or split evenly.
Due to the fact that interface stats are being used, the label stack cannot be sampled on the final hop or for single hop LSPs.
The 7250 IXR does not support outputting egress MPLS Cflowd Stats from the head-end. Cflowd must be collected on the head-end neighbor ingress.
IPFIX standard is limited to 10 labels, so ADJ-SIDs and service/entropy labels cannot exceed 10.
Collection of flow records from multi-vendor nodes is not supported. It may be possible to collect statistics further downstream where there is a higher chance of not being able to distinguish parallel LSP Paths and incorrectly accounting for the proportion of traffic carried by each LSP Path.

Steps


1	Enable and configure flow aggregation using the following parameter values; see the NSP Data Collection and Analysis Guide for information about configuring flow data collection: aggregation interval—5 LSP stack estimated bitrate—5
2	Provide 7250 IXR routers with the required configuration, as follows: `A:SR_12# configure cflowd` `A:SR_12>config>cflowd# info` `----------------------------------------------` `active-timeout 1` `inactive-timeout 59` `use-vrtr-if-index` `rate x` `collector x.x.x.x version 10` `template-set mpls-ip` `exit` `----------------------------------------------` `A:SR_12>config>router# interface "abcd"` `A:SR_12>config>router>if# info` `----------------------------------------------` `cflowd-parameters` `sampling unicast type interface direction ingress-only` `exit` `no shutdown` `----------------------------------------------` The following parameter values are important: active-timeout: the window of time used by the router to calculate flows (in minutes). In this example, with it set to 1, each minute the router will send its flow sample for that 1 minute to the collector. This value needs to be smaller or equal to the Estimated Bitrate set on the FC. The values presented for active-timeout and inactive-timeout are suggested values, but they may need to be tuned based on an analysis of Cflowd statistics on the node. sample-rate: the rate at which the router samples flows. With a rate of 1, each sample is used and sent to the collector. With a rate of 100, 1 out of 100 samples will be used. When running lower amounts of traffic and flows, a smaller sample rate is ideal. With more traffic a higher sample rate is recommended to not use an excessive amount of processing power and affect routing. use-vrtr-if-index: this instructs Cflowd export to use the virtual IF index rather than the global IF index. This configuration is required. rate: determine an appropriate rate based on the flow rate supported by your platform of 7250 IXR gen 1 that can be obtained from Nokia Support. See the nodal documentation for more information about these configuration parameters.
3	Configure Cflowd to use virtual interface index. `cflowd` `use-vrtr-if-index`
4	Perform the following configuration in the nrcp block of the /opt/nsp/configure/config/arm-system.conf file: `nrcp {` `telemetry {` `sr-te {` `stats_wipe_interval_in_seconds = 120` `stats_time_to_live_in_seconds = 600` `}` `}` `}` End of steps

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