An infrastructure for serving client nodes is disclosed, wherein the infrastructure comprises: a first plurality of service nodes; a second plurality of client nodes; and at least one linking server for providing connecting information to enable the nodes to establish connections between each other, wherein each service node provides service to at least one of the second plurality of client nodes through P2P connections respectively, and a first service node of the first plurality of service nodes acts as a client node to receive service from a second service node of the first plurality of service nodes.