System for access to an application distributed over a network of nodes deployed on a communication architecture (A), by a client (C) connected to this architecture. It comprises a server (S) having means for providing on the request of the client information about a set of nodes of the network (Np) taking into account the topology of the network within the communication architecture. It furthermore comprises at least one relay device (R) able to receive the information and at least one mediation device (M) suitable for establishing communications between the client (C) and at least some of the nodes of the set which are determined on the basis of the information provided by the relay device or devices (R).