The methods of the present invention enable wireless gateway nodes to support mobile node services, such as content based billing, when a data treatment server is present in the system. Using one of a defined Content Flow Label (CFL), an Application Program Interface (API), and a compression protocol header, the present invention provides content based billing by exchanging content and byte count information with the data treatment server. In one embodiment, a new compression protocol header type is defined. In a second embodiment, a content flow label with a byte count field is inserted in a Generic Routing Encapsulation (GRE) header. In an alternate embodiment, the wireless gateway node implements an API to transfer the content flow label and byte count information over a signaling link. In yet another embodiment, the data treatment server performs the content based billing and similar mobile node services.