Origin-State-Id AVP Support on P-GW

This chapter describes the following topics:

Feature Summary and Revision History

Summary Data

Applicable Product(s) or Functional Area

P-GW

Applicable Platform(s)

  • ASR 5500

  • VPC - DI

  • VPC - SI

Feature Default

Disabled - Configuration Required

Related Changes in This Release

Not Applicable

Related Documentation

  • AAA Administration Guide

  • Command Line Interface Reference

  • Statistics and Counters Reference

Revision History

Revision Details

Release

Introduced support for indirectly connected Policy and Charging Rules Functions (PCRFs) through Diameter Routing Agent (DRA).

21.17

First introduced.

21.6

Feature Description

The interfaces connected to the P-GW use Diameter protocol for communcation. This protocol provides a mechanism through the Origin-State-Id AVP to detect sessions that are terminated due to unanticipated shutdown of a peer node.

Storing the Origin-State-Id AVP of a peer node enables the P-GW to detect and clear sessions whenever there is a change in the Origin-State-Id of the diameter peer node. This ensures that the diameter-nodes are always synchronized with the P-GW. To enable this functionality of storing the Origin-State-Id AVP on the P-GW, the osid-change CLI command is introduced at the diameter endpoint level.

Origin-State-Id change detection is applicable only for PCRF nodes.

How It Works

When the osid-change CLI command is configured, the diabase starts storing the Origin-State-Id of each peer configured under a diameter endpoint. On receiving a diameter message from a peer, if the Origin-State-Id AVP is present, it is compared with the stored Origin-State-Id. If the received Origin-State-Id is greater than the stored one, gateway will start clearing calls. The Session Manager marks all the subscribers connected to the diameter-session for deletion and starts clearing sessions in a staggered manner. Clearing calls in a staggered manner helps avoid a storm of messages on other connected interfaces. When a subscriber is marked for deletion, the GW drops all the outbound diameter messages on the interface.

As per RFC 6733 (Diameter Base Protocol) Origin-State-Id could come in any diameter message, so the Gateway provides support to detect the change in CEA, CCA and RAR messages.

This feature is supported only with diamproxy mode (single and multiple).

Configuring Origin State Identifier AVP Support on P-GW

The following section provides the configuration command to enable or disable the functionality.

Configuring Origin-State-Id AVP on P-GW

Use the following CLI commands to store the Origin-State-Id AVP of a Diameter peer node on the P-GW. This command is introduced at the diameter endpoint level. 

configure 
   context  context_name 
      diameter endpoint endpoint_name  
         [no] osid-change action clear-subscribers 
         end

NOTES:

  • no: Disables the command.

  • action: Specifies the action to be taken.

  • clear subscribers: Clears subscribers connected to the peer.

  • This functionality is disabled by default.

Monitoring and Troubleshooting

This section provides information regarding show commands and/or their outputs in support of this feature.

Show Commands and/or Outputs

The output of the following CLI command has been enhanced in support of the feature.

show diameter

As part of this functionality, the show diameter CLI now includes the values for the following new fields:

  • osid-info sessmgr all

  • osid-info sessmgr instance_number

show session disconnect-reasons

The show session disconnect-reasons CLI now includes the osid-change field.

Bulk Statistics

The following bulk statistics are added in the System schema to support this feature:

Bulk Statistics

Description

disc-reason-656

Indicates the total number of sessions cleared due to change in Origin-State-Id of the Diameter peer.