An exemplary method includes generating an access record associated with a data session provided by at least one access layer element over an access network, generating an application record associated with an application provided by at least one application layer element over the access network, transmitting data representative of a correlation parameter associated with application from the at least one application layer element to the at least one access layer element via an inter-layer liaison subsystem, and inserting the correlation parameter associated with application and received from the at least one application layer element via the inter-layer liaison subsystem in the access record. In some examples, the method further includes correlating the access record and the application record based on the correlation parameter associated with the application. Other exemplary inter-layer parameter liaison methods and systems are also disclosed.