The invention enables a standard client according to the DVB-IPI phase 1 standard and connected within a local area network interconnected with a service delivery network via a non-transparent gateway to discover all the services offered to it both by the external delivery network an d by the servers in its local area network. The invention is based mainly on a service discovery aggregation functionality that we call ''SD & S proxy'' implemented on any one of the devices connected to the local area network running jointly with an ad-hoc configureuration of the gateway.