Showing papers by "Takeshi Kubo published in 2007"

Communication device whose address can be changed during communication, system, and communication method

Abstract: PROBLEM TO BE SOLVED: To provide a communication device whose present address can be changed while a communication is maintained. SOLUTION: The communication device has a set of two port numbers as a connection identifier, one is a receiving end port number that is a port number used by a communication device at the other end of the connection and the other is a sending end port number that is a port number used by itself. When a connection is established, the communication device determines the connection identifier of the connection to establish by negotiating with a communication device at the other end of the connection so as not to make the connection identifier overlap with the connection identifier of the other connection that has been established already. COPYRIGHT: (C)2007,JPO&INPIT

Address management method in plurality of dhcp servers, dhcp server, and program

Abstract: PROBLEM TO BE SOLVED: To provide an address management method or the like whereby a load of address management is not concentrated on one DHCP server even when many clients are connected to one address space SOLUTION: A plurality of DHP servers are connected to one address space A first DHCP server allocates first address to a client In this case, the first DHCP server transmits an allocation inhibit request including the first address to a second DHCP server On the other hand, the second DHCP server brings "allocation inhibit" to the first address included in the allocation inhibit request Further, when a lease period of the first address elapses, the first DHCP server transmits an inhibit release request including the first address to the second DHCP server The plural DHCP servers may preferably be interconnected to a ring network through which a packet is circulatingly transferred COPYRIGHT: (C)2008,JPO&INPIT

Method of certification of user, certification server, and system

Abstract: PROBLEM TO BE SOLVED: To provide a user certificating method wherein the principle certification is performed by the certification server of external domain even upon connection from an external domain to suppress the traffic for certification generated between the external domain and a home domain as much as possible SOLUTION: Respective certification servers preserve a global key for own domain and another global key for a domain to permit roaming A communication terminal which receives certification transmits a ticket including ticket data coded by the global key of home domain of the communication terminal together with a user discriminating information and the home domain discriminating information to the certification server, which receives the ticket, judges the global key of home domain of the communication terminal, based on the received home domain discriminating information, and carries out the certification by decoding the ticket data employing the judged global key COPYRIGHT: (C)2007,JPO&INPIT

Network system, resource allocation method and resource allocation program

Abstract: PROBLEM TO BE SOLVED: To provide a network system in which loads on a resource allocation management server can be suppressed. SOLUTION: The network system has a resource management server for setting QoS to a router in order to perform information communication between a call origination side apparatus and a call termination side apparatus through the router, and the network system is provided with: a means for receiving a response to a QoS generation request transmitted by the call termination side apparatus to the resource management server; a means for transmitting a token including QoS setting information from the call termination side apparatus to the call origination side apparatus; and a means for setting the QoS of the router on the basis of the QoS setting information included in the token. COPYRIGHT: (C)2009,JPO&INPIT

Mobile communication system and mobile communication program

Abstract: PROBLEM TO BE SOLVED: To improve processing efficiency in an entire mobile communication network. SOLUTION: A mobile communication system has: a means for establishing a first tunnel between a first current edge router storing a first terminal and a home edge router storing an IP address acquired by a second terminal; a means for establishing a second tunnel between a second current edge router storing the second terminal and the home edge router; a means for reestablishing the first tunnel between the first and second current edge routers; a means for establishing a third tunnel between the current edge router before the movement of the second terminal and that after the movement of the second terminal when the reestablishment of the first tunnel is required; and a means for reestablishing the third, first, and second tunnels in this order, based on information on the second terminal when the reestablishment of the first, second, and third tunnels is required. COPYRIGHT: (C)2009,JPO&INPIT

Packet transfer method, router, ring segment router and program in interconnection ring network

Abstract: PROBLEM TO BE SOLVED: To provide a packet transfer method, a router, a ring segment router and a program capable of transferring a packet with a simple sequence even when a mobile terminal moves to a different ring network in an interconnection ring network. SOLUTION: The mobile terminal moved from a first ring network to a second ring network transmits a position registration request including an address of the mobile terminal to a second router. The second router transmits the position registration request to the second ring network. Then a second ring segment router transmits the position registration request to a first ring segment router connected to the first ring network acting like a moving source. On the other hand, the second ring segment router transmits a packet received from the first ring segment router to the second ring network and the second router transmits the packet to the mobile terminal. COPYRIGHT: (C)2008,JPO&INPIT

Portable terminal for selecting routing protocol for ad hoc network, and program

Abstract: PROBLEM TO BE SOLVED: To provide a portable terminal, or the like for selecting a protocol in an ad hoc network in which a plurality of terminals having a plurality of ad hoc routing protocols exist. SOLUTION: The portable terminal comprises a protocol information table management section in which the protocol information table of ad hoc routing is stored; a protocol advertisement reception section that receives a protocol advertisement packet including protocol information from one's party terminal, registers the protocol information included in the protocol advertisement packet at the protocol information table of the protocol information table management means, and selects desired protocol information from the protocol information table; and a routing protocol starting section for starting the protocol based on the desired protocol information. The protocol advertisement packet is prescribed by an ICMP header, and contains a protocol name, a version number, a network name, and priority, or one of them for each protocol information. COPYRIGHT: (C)2007,JPO&INPIT

A proposal on mobility support in transport layer

Abstract: Most mobility protocols so far require support from the networks. Therefore, it is difficult for the user to take advantage of mobility anywhere because all of the networks need to support the same mobility protocol. In this paper, we propose a method of achieving mobility in the transport layer. The proposed method can be applied to any transport layer protocol, such as TCP, UDP, etc. We also demonstrate an implementation design for application of the proposed method. Furthermore, we show the feasibility of the proposed method through an experiment using the implemented system.