APPARATUS AND A METHOD FOR FLEXIBLY SELECTING AND ROUTING PLURAL ISPS, ESPECIALLY CONCERNED WITH USING MANY COMMON LINES IN AN IPV6 ENVIRONMENT

摘要

PURPOSE: An apparatus and method for flexibly selecting and routing plural ISPs(Internet Service Providers) is provided to minimize communication costs by using many common lines in an IPV6 environment, without using a dedicated line, thereby enabling a user to access to the Internet through a different common line although a problem is generated in any common line. CONSTITUTION: An apparatus(42) for flexibly selecting and routing plural ISPs consists of the first and second ISP prefix/IP address receiving parts(81,82), a router advertising message transmitting part(83), a data packet receiving part(84), a data packet transmitting part(85), an Internet access service providing ISP selection part(86), an Internet access service providing ISP prefix allocation part(87), and an IP header/routing header IP address exchange part(88). In the case of routing a data packet from a host(42) to an external node(49) in an environment that both the first ISP(46) and the second ISP(47) provide an Internet access service, the first ISP prefix/IP address receiving part(81) receives a prefixes and IP addresses from the first ISP(46,47). The second ISP prefix/IP address receiving part(82) receives a prefixes and IP addresses from the second ISP(47). The router advertising message transmitting part(83) transmits a router advertising message to all the nodes(42,43) of the first subnet. The data packet receiving part(84) receives the first data packet from the host(42). The data packet transmitting part(85) transmits the first data packet to the external node(49) through the first ISP(46) and the Internet(48).