Online charging with WebLogic Network gatekeeper

WebLogic Network Gatekeeper, WLNG, is an excellent tool for providing your partners with a standardized, yet simple interface to the telecom network.

In WLNG there is a very powerful functionality for doing policy control. When a request is sent from the application down to the network, i.e. an SMS, WLNG performs policy control. In the policy control it is checked that the application sending the request is not violating any limitations agreed upon between the service provider (hosting the application) and the operator. These checks could for example be that the application is only allowed to send 10 SMS per second or that the number is not allowed to receive anything from this application.



The policy check is done on all calls going from the application to the network and on all calls going from the network to the application. In the documentation for WLNG you can find the exact point in which the policy check is performed and the name of the check. So these checks are always performed to validate the current SLA.



However this is not enough. You can add your own policy checks in plain Java code as a compliment to the SLA data. What's good does that do, you may ask?



Well, it allows you to do additional checks in other systems before passing the request to the network or the application. Since these checks are done on all calls to and from the network you can do a check before a call goes to the network and then if the network managed to deliver it you can do an update of that same call.



How is this done? WLNG provides a message id that can be used to correlate the two calls. So when a call goes from the application to the network a call can be made to another system using the message id. When the network has successfully delivered the message the policy call is made once again with the same message id. The external system can use the message id to correlate the two calls.



So what can this be used for? One example from the real world is online charging. This example is valid for both calls from the network to an application as from an application to the network. Let's assume an application is sending an SMS with weather information as requested to a user's mobile terminal. When the policy is applied according to the SLA there is also a piece of Java code executing. It connects to the charging system and validates that the user has enough credit on his/her account. If that is the case the SMS is send to the network for final delivery to the user. When the user's terminal acknowledges the SMS the network is sending a delivery report back to WLNG. When WLNG receives this report is applies policy again and the Java code is executed again. This time it connects to the online charging system and uses the message id to correlate with the previous check made when sending the message. It charges the user according to the delivered message.



This is just one case where the flexible policy engine in WLNG can be used to create much more functionality than first thought of. Do you have any more ideas of what could be done using the policy engine and executing Java code inside it?