A method, for use in a proxy server, of accessing from a client system connected to an Internet (IP) network, a server system connected to the proxy server by a non-permanent connection through a circuit-switching network, the method comprising:
- receiving from the client system a request for accessing information located in the server system, the request comprising a source IP address and a destination IP address;
- identifying in the request, a destination IP address of the server system, the server system being connected to the proxy server through the circuit-switching network;
- determining the resource identifier of the server system in the circuit-switching network referring to a first table, the first table comprising, for each server system identified by a destination IP address, a resource identifier in the circuit-switching network;
- establishing a non-permanent connection with the server system using the resource identifier associated with the server system;
- retrieving the information requested by the client system from the server system;
- and
- sending the requested information to the client system.