This paper proposes a novel IP multihoming scheme in which fast packet processing nodes switch and distribute the traffic on an application flow basis. The newly developed node, called A-BOX, classifies each incoming packet up to the layer 4(L4) or L7(payload) header, edits it as necessary, and forwards it to an outgoing port according to the header's entry. The NATlike sandwiched path formed between A-BOXs acts like one path defined for an application flow, and so suits applications that have QoS(Quality of Service) requirements. A-BOX realizes wire rate forwarding by applying hardware techniques including FPGAs. A-BOX can measure the traffic on a real time basis for each flow and distribute the flow to achieve the application's requirements. The software interface of A-BOX means that the network can be transparently controlled for each application flow. We clarify the feasibility of A-BOX's basic methods, which include network condition monitoring via individual flow with huge background traffic, switching a specified flow in the multihoming condition, and traffic sharing/bandwidth aggregation.