A system and a method of transmitting information between a first node and a second node interconnected by communications networks, the first node sending data to the second node at two different addresses so that said data sent by the first node to said two different addresses is routed over two different paths to a single network address of the second node. At least one of the wall surfaces of the common chamber, along the predetermined direction, has a pressure absorbing surface with a rigidity lower than those of other wall surfaces and configured to absorb a pressure change, and the pressure absorbing surface is formed by a pressure absorbing member having a non-uniform thickness. Any counterexample appearing is evaluated to determine whether it is caused by a defective model or whether it should have been avoided by reformulating the property within the scope of the specification.