Charging method and device

A charging method, comprising:

• sending, by a policy and charging rules function (PCRF) entity, a data flow charging policy to a PCEF entity, wherein the data flow charging policy comprises correlation information, so that the PCEF entity generates, according to the data flow charging policy, first charging information that carries a correlation identifier of a data flow borne by the PCEF entity;
• and
• sending, by the PCRF entity, an application charging policy to a traffic detection function TDF entity, wherein the application charging policy comprises charging correlation information, so that the TDF entity generates, according to the application charging policy, second charging information that carries a correlation identifier of a data flow of an application borne by the TDF entity, wherein the correlation identifier of the data flow borne by the PCEF entity and the correlation identifier of the data flow of the application borne by the TDF entity are used by a charging system to perform correlation processing for the first charging information and the second charging information.

A traffic detection function TDF entity, comprising:

• an acquiring module, configured to acquire a correlation identifier of a data flow of an application borne by the TDF entity;
• and
• a sending module, configured to send first charging information to a charging system, wherein the first charging information carries the correlation identifier of the data flow of the application borne by the TDF entity, so that the charging system performs, according to the correlation identifier of the data flow of the application borne by the TDF entity and a correlation identifier of a data flow borne by a policy and charging enforcement function PCEF entity, correlation processing for the first charging information and second charging information that is sent by the PCEF entity to the charging system, wherein the second charging information carries the correlation identifier of the data flow borne by the PCEF entity.