Network system, terminal, and gateway

Abstract

A virtual interface having a global address of a physical interface on an Internet side of a gateway is provided in a terminal. An application unit of the terminal transmits a packet to the Internet using the virtual interface. The packet is transferred to the gateway through a downlink transfer path. The gateway transmits the packet from the physical interface on the Internet side to the Internet.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic of a network system according to embodiments of the present invention;

FIG. 2 is a schematic for illustrating a sequence of data transfer processing by the network system according to the embodiments;

FIG. 3 is a schematic for illustrating a transition of packet formats in downlink transfer in the network system according to the embodiments;

FIG. 4 is a schematic for illustrating a transition of packet formats in uplink transfer in the network system according to the embodiments;

FIG. 5 is a schematic of a network system according to a first embodiment of the present invention;

FIG. 6 is a schematic for illustrating detailed configuration of the network system according to the first embodiment;

FIG. 7 is a schematic for illustrating a transfer table of a terminal according to the first embodiment:

FIG. 8 is a schematic for illustrating a route table of the terminal according to the first embodiment:

FIG. 9 is a schematic for illustrating a transfer table of a gateway according to the first embodiment;

FIG. 10 is a schematic for illustrating a route table of the gateway according to the first embodiment;

FIG. 11 is a schematic for illustrating a process sequence from creation of a virtual interface to setting of transfer paths;

FIG. 12 is a schematic for illustrating a process sequence at the time of reception of a packet in the network system according to the first embodiment;

FIG. 13 is a schematic for illustrating a transition of packet formats at the time of reception of a packet in the network system according to the first embodiment;

FIG. 14 is a schematic for illustrating a process sequence at the time of transmission of a packet in the network system according to the first embodiment;

FIG. 15 is a schematic for illustrating a transition of packet formats at the time of transmission of a packet in the network system according to the first embodiment;

FIG. 16 is a schematic of a network according to a second embodiment of the present invention;

FIG. 17 is a schematic for illustrating detailed configuration of the network system according to the second embodiment;

FIG. 18 is a schematic for illustrating a transfer table of a terminal according to the second embodiment:

FIG. 19 is a schematic for illustrating a transfer table of a gateway according to the second embodiment;

FIG. 20 is a schematic for illustrating a transition of packet formats at the time of reception of a packet in the network system according to the second embodiment;

FIG. 21 is a schematic of a network system according to a third embodiment of the present invention;

FIG. 22 is a schematic of a network system according to a fourth embodiment of the present invention;

FIG. 23 is a schematic for illustrating a transition of packet formats at the time of reception of a packet in the network system according to the fourth embodiment;

FIG. 24 is a schematic for illustrating a transition of packet formats at the time of transmission of a packet in the network system according to the fourth embodiment;

FIG. 25 is a schematic of a network system according to a fifth embodiment of the present invention;

FIG. 26 is a schematic for illustrating a transfer table of a terminal according to the fifth embodiment:

FIG. 27 is a schematic for illustrating a transfer table of a gateway according to the fifth embodiment;

FIG. 28 is a schematic for illustrating a process sequence at the time of reception of a packet in the network system according to the fifth embodiment;

FIG. 29 is a schematic for illustrating a transition of packet formats at the time of reception of a packet in the network system according to the fifth embodiment;

FIG. 30 is a schematic for illustrating a process sequence at the time of transmission of a packet in the network system according to the fifth embodiment;

FIG. 31 is a schematic for illustrating a transition of packet formats at the time of transmission of a packet in the network system according to the fifth embodiment;

FIG. 32 is a schematic of a network system according to a sixth embodiment of the present invention;

FIG. 33 is a schematic for illustrating detailed configuration of the network system according to the sixth embodiment;

FIG. 34 is a schematic for illustrating a process sequence at the time of changing attributes of a virtual interface in the network system according to the sixth embodiment;

FIG. 35 is a schematic for illustrating an instruction format issued by “ioctl” according to the sixth embodiment;

FIG. 36 is a schematic for illustrating an attribute change notice according to the sixth embodiment;

FIG. 37 is a schematic for illustrating a process sequence at the time of changing attributes of a physical interface in the network system according to the sixth embodiment;

FIG. 38 is a schematic for illustrating a terminal managing unit of the gateway according to the sixth embodiment;

FIG. 39 is a schematic for illustrating detailed configuration of the network system according to a seventh embodiment of the present invention;

FIG. 40 is a schematic for illustrating a process sequence at the time of changing attributes of a virtual interface in the network system according to the seventh embodiment; and

FIG. 41 is a schematic for illustrating a terminal managing unit of the gateway according to the seventh embodiment.

Claims

1. A network system comprising: a gateway device arranged on a border between a public network and a private network, and configured to relay data communicated therebetween;a terminal located in the private network, including a virtual interface that corresponds to a physical interface of the gateway on a public network side, and configured to transmit and receive data to and from other terminals located on the public network through the virtual interface; anda transfer path configured to transfer data between the physical interface and the virtual interface.

2. The network system according to claim 1, wherein the transfer path is set by opening a communication port with respect to the virtual interface by the terminal.

3. The network system according to claim 1, wherein the terminal includes a first transmitting unit configured to transmit, to the gateway, information on a change in attributes of the virtual interface, andthe gateway includes a first changing unit configured to reflect the change of attributes in attributes of the physical interface.

4. The network system according to claim 3, wherein the gateway includes a managing unit configured to manage at least one terminal having the virtual interface that corresponds to the physical interface; anda second transmitting unit configured to transmit information on a change in attributes of the physical interface to the terminal, andthe terminal includes a second changing unit configured to reflect the change of attributes in attributes of the virtual interface.

5. The network system according to claim 4, wherein, a plurality of terminals are arranged on the private network, andthe first transmitting unit is configured to transmit, when the gateway receives the information on the change in attributes of the virtual interface from the first transmitting unit of one of the terminals, the information on the change in attributes of the physical interface, to all of the terminals except for the one of the terminals.

6. A terminal comprising a virtual interface configured to correspond to a physical interface of a gateway on a public network side, the gateway arranged on a border between a public network and a private network and configured to relay data communicated therebetween, wherein the terminal is configured to transmit and receive data to and from other terminals located on the public network through the virtual interface using a global address assigned to the physical interface.

7. The terminal according to claim 6, further comprising: a communicating unit configured to communicate with the other terminals;a path setting unit configured to set a downlink transfer path for transferring data to the gateway;a transferring unit configured to transfer, to the gateway, data that has been transmitted to the virtual interface from the communicating unit, through the downlink transfer path; anda receiving unit configured to receive data transferred through the gateway from the other terminals and to deliver received data to the communicating unit through the virtual interface.

8. The terminal according to claim 7, further comprising: a destination setting unit configured to add, to the data to be transferred to the gateway, a header including destination information;a determining unit configured to determine an interface to which the data is to be output at a destination of the data; anda deleting unit configured to delete the header from data addressed to the terminal and transferred from the gateway.

9. The terminal according to claim 8, further comprising: a dividing unit configured to divide data to be transferred to the gateway into a plurality of pieces;a transmission/reception control unit configured to add a header including a transmission/reception confirmation number, to the pieces:a re-transmission control unit configured to re-transmit, when no reception response to the pieces transmitted to the gateway is received from the gateway, transmitted pieces to the gateway, and configured to transmit, when data is received externally, a reception response to a source from which received data is transmitted; anda reconstructing unit configured to re-construct a plurality of pieces of data transferred from the gateway into original data.

10. The terminal according to claim 7, further comprising: an identifier setting unit configured to add an identifier indicating that data is processed by the gateway, to data transferred to the gateway;a identifier judging unit configured to judge whether data is processed based on a type of the identifier; anda identifier deleting unit configured to delete attached identifier, when the identifier judging unit judges data to be processed.

11. A gateway used in a network system that includes a gateway device that is arranged on a border between a public network and a private network, and that relays data communicated therebetween, a terminal that is located in the private network, that includes a virtual interface corresponding to a physical interface of the gateway on a public network side, and that transmits and receives data to and from other terminals located on the public network through the virtual interface using a global address assigned to the physical interface; the gateway comprising: a path setting unit configured to set an uplink transfer path for transferring data to a terminal located in the private network;a data transferring unit configured to transfer data received from a terminal on the public network, to the terminal in the private network through the uplink transfer path; anda data receiving unit configured to receive data transferred from the terminal in the private network and to transmit the data to the public network.

12. The gateway according to claim 11, further comprising a destination determining unit configured to determine a terminal to be a transfer destination, from among a plurality of terminals located in the private network, based on a destination port number of data received from the terminal on the public network.

13. The gateway according to claim 11, further comprising: a destination setting unit configured to add a header including destination information to the data to be transferred to the terminal in the private network;a determining unit configured to determine an interface to which the data is to be output at a destination of the data; anda deleting unit configured to delete the header from data addressed to the gateway and transferred from the terminal in the private network.

14. The gateway according to claim 13, further comprising: a dividing unit configured to divide data to be transferred to the terminal in the private network into a plurality of pieces;a transmission/reception control unit configured to add a header including a transmission/reception confirmation number, to the pieces:a re-transmission control unit configured to re-transmit, when no reception response to the pieces transmitted to the terminal in the private network is received from the terminal in the private network, transmitted pieces to the terminal, and configured to transmit, when data is received externally, a reception response to a source from which received data is transmitted; anda reconstructing unit configured to re-construct a plurality of pieces of data transferred from the terminal in the private network into original data.

15. The gateway according to claim 11, further comprising: an identifier setting unit configured to add an identifier indicating that data is processed by the terminal, to data transferred to the terminal in the private network;a identifier judging unit configured to judge whether data is processed based on a type of the identifier; anda identifier deleting unit configured to delete attached identifier, when the identifier judging unit judges data to be processed.