A method (100, 100') of dynamically allocating resources of an IP network for communication between at least one source application running in a source domain and at least one sink application running in a sink domain, the source domain being connected to the IP network via a source partitioning and encryption means and the sink domain being connected to the IP network via a sink partitioning and encryption means, the IP network having a dynamic resource allocation functionality (32, 33, 52, 53) for the streams that it carries, said method being characterised in that it comprises the successive steps of: - generating an application stream by the at least one source application; - creating a resource allocation instruction for an application stream from the source application to the sink application; - generating a sub-stream, the IP packets of the sub-stream being characteristic while having addressing similar to an addressing of the packets of the application stream; - inserting the IP packets of the sub-stream into the application stream so as to encode the resource allocation instruction into a combined stream; - encrypting the IP packets of the combined stream using the source partitioning and encryption means, to obtain an encrypted combined stream; - analysing the combined encrypted stream downstream of the source partitioning and encryption means, so as to decode the resource allocation instruction; - transmitting the decoded resource allocation instruction to the dynamic resource allocation functionality of the IP network; - making a resource allocation decision, by the dynamic resource allocation functionality of the IP network; - routing the encrypted combined stream to the sink partitioning and encryption means through the IP network, according to the resource allocation decision made by the dynamic resource allocation functionality of the IP network; - decrypting the IP packets of the encrypted combined stream by the sink partitioning and encryption means, to obtain a decrypted combined stream; - separating, in the decrypted combined stream, the sub-stream and the application stream; and - receiving the application stream by the at least one sink application. - generating an application stream by the at least one source application; - creating a resource allocation instruction for an application stream from the source application to the sink application; - generating a sub-stream, the IP packets of the sub-stream being characteristic while having addressing similar to an addressing of the packets of the application stream; - inserting the IP packets of the sub-stream into the application stream so as to encode the resource allocation instruction into a combined stream; - encrypting the IP packets of the combined stream using the source partitioning and encryption means, to obtain an encrypted combined stream; - analysing the combined encrypted stream downstream of the source partitioning and encryption means, so as to decode the resource allocation instruction; - transmitting the decoded resource allocation instruction to the dynamic resource allocation functionality of the IP network; - making a resource allocation decision, by the dynamic resource allocation functionality of the IP network; - routing the encrypted combined stream to the sink partitioning and encryption means through the IP network, according to the resource allocation decision made by the dynamic resource allocation functionality of the IP network; - decrypting the IP packets of the encrypted combined stream by the sink partitioning and encryption means, to obtain a decrypted combined stream; - separating, in the decrypted combined stream, the sub-stream and the application stream; and - receiving the application stream by the at least one sink application.