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Preventing Excessive Media Inactivity Notifications

You can prevent a PG from sending an excessive number, or avalanche, of media inactivity notifications to the PGC in a short period of time. Such an avalanche can severely degrade the performance of the PGC. By default, all media inactivity notifications are sent immediately from the PG to the PGC. When an upstream device in the network fails, all existing terminations in the PG report media inactivity at about the same time. You can configure H.248 notification behavior to regulate the flow of notifications sent to the PGC.

Regulated notification is activated either by a request from the PGC or by CLI commands. When you choose regulated notification you can explicitly configure the frequency for notifications of media inactivity events as follows:

Send only one media inactivity notification. This option is not available as part of the H.248 notification behavior package.
Send a configurable percentage of media inactivity notifications ( 0 through 100).

Notification History—The Notification Behavior Package only limits the sending of notifications to the PGC, not the occurrences of the event. We recommend you enable the recording of all media inactivity notifications for future retrieval and, optionally, request that the inactivity notifications time stamps are also enabled for future retrieval.

Configuring H.248 Notification Behavior to Prevent Excessive Media Inactivity Notifications

By properly setting H.248 notification behavior properties, you can prevent a PG from sending an avalanche of media inactivity notifications that can flood the PGC and adversely affect the processing of H.248 transactions. You can also enable recording of all media inactivity events for future retrieval.

The H.248 Notification Behavior package is defined in annex E.15 of the Gateway control protocol v.3, ITU-T Recommendation H.248.1, September, 2005.

Step-by-Step Procedure

To configure default values for H.248 Notification Behavior properties:

Access the configuration of H.248 application-data-inactivity-detection. [edit services pgcp gateway vpg-1] user@host#edit h248-properties application-data-inactivity-detection
Turn notification on.[edit services pgcp gateway vpg-1 h248-properties application-data-inactivity-detection] user@host#set ip-flow-stop-detection regulated-notify
Access the configuration of H.248 notification behavior.[edit services pgcp gateway vpg-1] user@host#edit h248-properties notification-behavior
Configure the default frequency of notification messages for the media inactivity event. The PGC can override this default by requesting a different frequency. If you specify once, only one notification is sent and the PGC cannot retrieve the notification by use of an audit for the root.termination.[edit services pgcp gateway vpg-1 h248-properties notification-behavior] user@host#set notification-regulation default 10
Enable retrieval of event notifications by the PGC at the [edit services pgcp gateway gateway-name h248-options] level.[edit services pgcp gateway vpg-1 h248-properties notification-behavior] user@host#edit services pgcp gateway vpg-1 h248–options [edit services pgcp gateway vpg-1 h248-options] user@host#set audit-observed-events-returns-history;
Enable retrieval of time stamps of recorded notifications by the PGC.[edit services pgcp gateway vpg-1 h248-options] user@host#edit services pgcp gateway vpg-1 h248-properties [edit services pgcp gateway vpg-1 h248-properties] user@host#set event-timestamp-notification request-timestamp requested

Managing the Rate for All Notifications Sent by a PIC

You can limit the rate at which the PIC send all notifications. Using this functionality, you can prevent an avalanche of media inactivity notifications and throttle all notifications to a configured rate. Doing this enables the system to maintain a stable state when the PIC is generating a large volume of messages.

Limiting The Rate for All Notifications from a PIC

You can configure the aggregate rate of notifications coming from a PIC. Using this approach, you limit the rate for all messages from the PIC, not just notifications.