Abstract: The invention relates to a method for supervising a communication session over a data network, said session including a first data flow, referred to as the parent flow, using a first protocol, said parent flow including data suitable for setting up a second data flow, referred to as the child flow, using a second protocol for said session, which includes: searching (13) the parent flow for the data that enable the child flow to be set up; generating (15) and storing (17) a signature, referred to as a parent key, using said data; auditing (19) data flows using the second protocol on the data network; creating (21) a signature for each one of the flows; comparing (23) said signature of each one of the flows with the parent key; and, if the comparison is positive, determining (25) that the data flow in question is the child flow of the session.