Flow statistics collection in the NFM-P

Introduction

The NFM-P can collect flow statistics from managed NEs. Although other criteria may apply, a flow is basically a series of IP packets that share a common source, destination, and type of payload, for example, traffic that is specific to an application.

When an NE is configured to collect flow statistics, the NE monitors the traffic on one or more interfaces to identify the flows, aggregates the flow data, and regularly exports flow data records to an external system.

The NFM-P uses NSP Flow Collectors to collect the following flow statistics from managed NEs:

• system Cflowd, for example, per-AS or per-subnet, for protocols such as:

  • IPFIX v10

  • IPFIX v10 (Nokia system Cflowd)

  • Jflow v5 (Juniper)

  • Jflow v5 (Juniper VM)

  • Netflow v5 standard (Cisco)

• AA Cflowd

• CGNAT

Note: CGNAT support remains restricted to the 7750 SR (for Format 1 and Format 2 CSV records only). See Flow statistics.

Functional description

An NSP Flow Collector processes the statistics records to create time-based aggregates based on various keys, or just collects the raw data.

The collected statistics data are managed using one or both of the following methods:

• Forwarding the statistics records to a target file server in different formats:

  • IPDR — AA Cflowd

  • CSV — CGNAT, comprehensive raw

• Storing the data in an NSP auxiliary database for use by the NSP Analytics — AA Cflowd, system Cflowd

An NSP Flow Collector also computes estimated bitrate data based on the system Cflowd MPLS-IP records and makes it available to IP resource control.

Developer tools

IPDR Reference

The NFM-P IPDR Reference lists and describes the fields in an IPDR-formatted record for each collection or aggregation domain based on user-specified criteria. The IPDR Reference also lists the IPDR schema changes between NFM-P releases.

NSP Flow Collector Fields Dependencies

For AA Cflowd, the NSP Flow Collector Fields Dependencies tool describes the relationships and dependencies between ISA-AA Cflowd IPFIX fields and the fields in the associated NSP Flow Collector aggregation records.

Based on the device type, template, data type, and aggregation, the tool displays:

• for each template field, the dependent aggregation fields

• for each aggregation field, the Cflowd fields that a Flow Collector requires to generate the aggregation field

Exporting IPDR file contents to other formats

For compatibility with an OSS application, you can use an NFM-P tool to export the contents of XDR-encoded IPDR statistics files to files in a format such as text or XML. Because the export process is resource-intensive, you must observe the following requirements before you attempt to use the tool.

• It is strongly recommended that you use the tool only on a standby NFM-P main server, whether collocated with a main database or in a distributed deployment.

• The system that receives the exported files must meet the following requirements.

  • The system must be dedicated to the export operation.

  • The output location must have sufficient space for the output files; a large network-attached storage system is recommended. An exported file is approximately six times the size of the associated input file.

• The user of the tool requires full access permissions on the input and output directories.

CLI- and GUI-based versions of the tool are available; see To export IPDR statistics files to a different format for information about how to export IPDR files.