Node device and network resource reservation method for data packet

Abstract

A network resource reservation scheme capable of making a resource reservation at the IP level according to the resource reservation protocol at a time of data packet transfer at the IP level using ATM networks. A node device requests a change of a virtual connection for transferring data packets to a prescribed virtual connection for providing a service which is capable of changing an amount of resource without reestablishing connections, when a prescribed message of a resource reservation protocol for that virtual connection is received, and transmits the data packets to the prescribed virtual connection established in response to the request. A node device determines a necessary amount of resource according to a requested quality of service described in a received reservation message of a resource reservation protocol. A node device then requests a change of an amount of resource reserved in a virtual connection for transferring data packets in order to reserve the necessary amount of resource in that virtual connection, and transmits the data packets to that virtual connection in which the amount of resource reserved therein is changed in response to the request.