Methods, systems, and computer readable media for detecting orphan sy or rx sessions using audit messages with fake parameter values

A system for detecting orphan Sy or Rx sessions using audit messages with fake parameter values, the system comprising:

• a policy and charging rules function (PCRF) including:
• a Diameter audit message generator for generating a Diameter message for auditing an application level Diameter session for which the PCRF maintains local resources for including, in the message, at least one fake parameter value, and for sending the message with the fake parameter value to an online charging system (OCS) or an application function (AF) over an Sy or Rx interface;
• and
• a Diameter audit response processor for receiving a response from the OCS or AF, for determining, based on the response, whether the application level session comprises and orphan session, and for, in response to determining that the application level Diameter session comprises an orphan session, freeing the local resources maintained by the PCRF for the orphan session.

A non-transitory computer readable medium having stored thereon executable instructions that when executed by a computer control the computer to perform steps comprising:

• at a policy and charging rules function (PCRF):
• generating a Diameter audit message concerning an application level Diameter session for which the PCRF maintains local resources;
• including, in the audit message, at least one fake parameter value;
• sending the audit message with the fake parameter value to an online charging system (OCS) or an application function (AF) over an Sy or Rx interface;
• receiving a response to the audit message from the OCS or AF;
• determining, based on the response, whether the application level session comprises and orphan session;
• and
• in response to determining that the application level Diameter session comprises an orphan session freeing the local resources maintained by the PCRF for the orphan session.