Addition of Server Unreachable Field in CDR

Feature Summary and Revision History

Summary Data

Applicable Product(s) or Functional Area

PGW

Applicable Platform(s)

  • ASR 5500

  • VPC-DI

  • VPC-SI

Related Changes in This Release

Not Applicable

Related Documentation

  • Command Line Interface Reference

  • PGW Administration Guide

  • Statistics and Counters Reference

Revision History


Important

Revision history details are not provided for features introduced before releases 21.2 and N5.1.

Revision Details

Release

Support is added for addition of server unreachable field in CDR.

21.27

First introduced.

21.22

Feature Description

When the Online Charging System (OCS) sends negative messages, transport connection fails between the Policy and Charging Enforcement Function (PCEF) and the OCS. The connection error causes session establishment failure and prevents subscribers from the use of services. The following procedures are used to overcome the connection errors:

  • Failure Handling (FH): The exisiting FH mechanism operates if the diameter session failover is present, allows the system to choose whether to continue the session and convert to offline, or to terminate the session when a connection or message-level error occurs.

  • Server Unreachability (SU): This failure handing mechanism provides more granular control over failure procedures. In addition to the session after the message- and connection-level (transport) failures, this mechanism is used when the responses are slow from the OCS. It also provides the options to either continue the session for a specific time duration or quota exhaustion before termination.

    To use the configured server and interim quota (volume and time), SU retries before a session is converted to offline or gets terminated.

When gtpp attribute servers-unreachable is configured under gtpp group and the SU feature is enabled then, serversUnreachableContinue or serversUnreachableTerminate in interim or final CDR allows the following process flow:

  1. SU failure is triggered.

  2. CDR is generated.

  3. Based on the SU configuration in Call Control Profile, the generated CDR contains the serversUnreachableContinue or serversUnreachableTerminate fields.

The following table describes the serversUnreachable fields in the CDR.

Table 1. ServersUnreachable Fields in CDR

Field Name

Description

Tag

Format

Size

ASN1 Code

serversUnreachableContinue

When servers unreachable procedure is executed, element is present.

256

Boolean

1

0x9f8200

serversUnreachableTerminate

When servers unreachable procedure is executed, element is present.

257

Boolean

1

0x9f8201
Table 2. ServersUnreachable CDR Fields in ACS Configuration

SU Configuration

SU Detected Fields during Interim State

SU Detected Fields After End of Interim State

SU not Detected Fields (normal call with Gy)

server-unreachable initial-request terminate

When a CDR field is triggered differently, do not include the SU terminate field since it is an interim CDR

  • SU continue is FALSE

  • SU Terminate is FALSE in final CDR

  • SU continue is FALSE

  • SU Terminate is TRUE in final CDR

  • SU continue is FALSE

  • SU Terminate is FALSE in final CDR

server-unreachable update-request terminate

When a CDR field is triggered differently, do not include the SU terminate field since it is an interim CDR

  • SU continue is False

  • SU Terminate is False in final CDR

  • SU continue is True in both interim and final CDR

  • SU Terminate is False in final CDR

  • SU continue is False

  • SU Terminate is False in final CDR

server-unreachable initial-request continue

  • SU continue is False

  • SU Terminate is False in final CDR

  • SU continue is True in both interim and final CDR

  • SU Terminate is False in final CDR

  • SU continue is False

  • SU Terminate is False in final CDR

server-unreachable update-request continue

  • SU continue is False

  • SU Terminate is False in final CDR

  • SU continue is True in both interim and final CDR

  • SU Terminate is False in final CDR

  • SU continue is False

  • SU Terminate is False in final CDR

For more information, refer to the Gy chapter in the PGW Administration Guide.

Adding Server Unreachable Field in CDR

Use the following configuration commands to add the server unreachable field in CDR:

configure 
   context context_name 
      gtpp group group_name 
         gtpp attribute servers-unreachable   
         end

NOTES:

  • gtpp attribute servers-unreachable: Specifying this option includes the optional field ServersUnreachablesContinue or ServersUnreachablesTerminate in the CDR.

Monitoring and Troubleshooting

This section provides information to monitor and troubleshoot this feature using show commands.

Show Commands and Outputs

This section provides information regarding show command and their outputs in support of this feature.

show gtpp group name <group name>

Field

Description

Servers Unreachable present

Displays "Yes" or "No" to indicate the presence of servers unreachable element.