About Policy Counter IDs

A policy counter ID defines the name, optional description, and default online charging server (OCS) value for which status can be received from the OCS server. After a policy counter ID is defined, you can use policy counter IDs in policies.

In the Sy reference point, an OCS acts as the server and the MPE device acts as the client. For a subscriber, the MPE device requests status from the OCS for a set of policy counter IDs. If the request is successful, the OCS returns the status information for the subscriber to the MPE device and an Sy session is created for the subscriber. The OCS automatically sets up a subscription for the requested policy counter IDs and then notifies the MPE device of any changes to those values.

The Sy protocol provides for four types of messages between the MPE device and the OCS:
  1. For the MPE device to request status for an initial set of policy counter IDs and subscribe for notifications for those policy counter IDs
  2. For the MPE device to request an update status and possibly update the policy counter ID subscription
  3. For the OCS to notify the MPE device of a status change for a set of policy counter IDs for a subscriber
  4. For the MPE device to end the Sy session with the OCS, cancelling all subscriptions associated with that session

You can define policy counter IDs in the CMP database and then refer to them in policies.