Patent ID: 7379967

Claim:
A download method for a file in a computer network comprising at least one client, a super seeder for transmitting a file stored in advance according to a request, and a tracker including an active peer table which is a table created for each file for storing at least an address of a client and/or a super seeder, a seeder flag for indicating whether a file stored by a computer at said address can be transmitted according to a request, and the number of computers that can transmit the stored file according to a request, and a super seeder table for storing the address of the super seeder, said tracker being a central control server that registers and manages addresses of the clients that participate in the computer network, the method comprising: a first step of sending an event start notice and a file download request notice from a client to a tracker; a second step of said tracker receiving said download request notice and registering said client in the active peer table corresponding to said file; a third step of said tracker retrieving an address of a super seeder from said super seeder table when the number of computers that can transmit said file is a predetermined value m, which is set in advance, or less in said active peer table; a fourth step of sending a process start instruction from the tracker to the super seeder retrieved in said third step; a fifth step of receiving said process start instruction and starting the process by said super seeder; a sixth step of sending a seeding start notice from said super seeder to the tracker; a seventh step of said tracker receiving said seeding start notice and registering said super seeder in said active peer table; an eighth step of downloading said file from said super seeder to said client based on said active peer table; a ninth step of sending a receive completion notice from the client to the tracker; a tenth step of said tracker receiving said receive completion notice and setting a seeder flag of said client in the active peer table corresponding to said file, and updating the number of computers that can transmit said file; an eleventh step of said tracker comparing the number of computers that can transmit said file with a predetermined threshold n; a twelfth step of said tracker generating a process stop request when the number of computers that can transmit said file exceeds the threshold n; a thirteenth step of said tracker sending said process stop request to the super seeder included in said active peer table; and a fourteenth step of receiving said process stop request and stopping the process by the super seeder.