Packet classification and routing in a data communication network with static routing procedure, wherein the routing is performed without using a routing table. First values for each common address bit of end service points adjacent to a switch as a response to a local subnet mask of the switch are defined. Then the packet flows from the current switch to the adjacent switches are forwarded in response to a value of differentiation bits. Unprocessed packets are forwarded to the main adjacent switch according to the main adjacent switch definition. Unforwarded are processed packets locally as exceptions.