Extraction, conversion, and transmission of user packet from encapsulated packet

1. A communication system comprising:

a network configuration apparatus that configures, as a cloud LAN (Local Area Network), a closed network constructed independently for each of a plurality of users on an open network, and generates an access point for accessing the cloud LAN, the access point being assigned to each of a plurality of terminals that belong to the user using the cloud LAN;

a user information management apparatus that selects the access point assigned to a connection terminal, the connection terminal being a terminal accessing the cloud LAN via a mobile data transfer network, out of the plurality of terminals, and notifies the connection terminal of the access point selected; and

an address management apparatus that delivers an address for the connection terminal to access the cloud LAN in response to a request from the connection terminal,

wherein the network configuration apparatus generates a PGW (Packet Data Network Gateway) that serves as an access point between the mobile data transfer network and the cloud LAN, and a cloud LAN switch that performs switching of a packet forwarded on the cloud LAN, and

wherein each of the PGW and the cloud LAN switch receives a first encapsulated packet from either one of the mobile data transfer network and the cloud LAN, extracts a user packet from the first encapsulated packet received, and converts the user packet extracted to a second encapsulated packet adapted to the other one of the mobile data transfer network and the cloud LAN to transmit the second encapsulated packet thereto.

2. The communication system according to claim 1 , wherein the user information management apparatus obtains specific information on the connection terminal via the mobile data transfer network to select the access point assigned to the connection terminal, based on the specific information obtained.

3. The communication system according to claim 1 , wherein the user information management apparatus notifies the connection terminal of the access point selected, via a base station connected to the connection terminal.

4. The communication system according to claim 1 , wherein the address management apparatus assigns a network identifier to the connection terminal, and generates a terminal management table that associates an identifier of the connection terminal with the network identifier assigned to the connection terminal and a network identifier of the access point assigned to the connection terminal,

wherein each of the PGW and the cloud LAN switch creates a transfer table used for transferring a received packet with reference to the terminal management table, determines a transfer destination network with reference to the transfer table, by using a network identifier included in the received packet as a search key, and transmits the received packet to the transfer destination network determined.

5. The communication system according to claim 4 , wherein the PGW

decapsulates the first encapsulated packet when the packet forwarded in a communication channel of the mobile data transfer network or the cloud LAN is encapsulated;

with reference to the transfer table, by using a network identifier extracted from the decapsulated packet as a search key, determines a network identifier of the packet transfer destination; and

encapsulates the packet adapted to the network of the packet transfer destination, by using the identifier determined network.

6. The communication system according to claim 4 , wherein the PGW, with reference to the transfer table, by using, as a search key, a network identifier corresponding to a destination of the first encapsulated packet forwarded from the cloud LAN, upon finding that the network identifier corresponding to the destination is present in the transfer table, registers the network identifier corresponding to the destination and a network identifier corresponding to a source of the first encapsulated packet in association with each other in the transfer table.

7. The communication system according to claim 4 , wherein the terminal management table includes

direct access information that specifies an entry to be registered with priority in the transfer table, and

wherein the PGW registers with priority an entry with the direct access information attached thereto in the transfer table.

8. A communication method comprising:

configuring, as a cloud LAN (Local Area Network), a closed network constructed independently for each of a plurality of users in an open network, and generating an access point for accessing the cloud LAN, the access point assigned to each of a plurality of terminals that belong to the user using the cloud LAN;

selecting the access point assigned to a connection terminal, the connection terminal being a terminal accessing the cloud LAN via a mobile data transfer network, out of the plurality of terminals, and notifying the connection terminal of the access point selected;

delivering an address for the connection terminal to access the cloud LAN in response to a request from the connection terminal;

generating a PGW (Packet Data Network Gateway) that serves as an access point between the mobile data transfer network and the cloud LAN, and a cloud LAN switch that performs switching of a packet forwarded on the cloud LAN;

receiving, by each of the PGW and the cloud LAN switch, a first encapsulated packet from either one of the mobile data transfer network and the cloud LAN;

extracting, by each of the PGW and the cloud LAN switch, a user packet from the first encapsulated packet received; and

converting, by each of the PGW and the cloud LAN switch, the user packet extracted to a second encapsulated packet adapted to the other one of the mobile data transfer network and the cloud LAN to transmit the second encapsulated packet thereto.

9. The communication system according to claim 4 , wherein the PGW serving as the access point assigned to the connection terminal, learns and associates a source address and an encapsulated source address of a user packet transmitted to the connection terminal to reflect association between the source address and the encapsulated source address in the transfer table.

10. The communication method according to claim 8 , further comprising:

obtaining specific information on the connection terminal via the mobile data transfer network to select the access point assigned to the connection terminal, based on the specific information obtained.

11. The communication method according to claim 8 , further comprising:

notifying the connection terminal of the access point selected, via a base station connected to the connection terminal.

12. The communication method according to claim 8 , further comprising:

assigning a network identifier to the connection terminal;

generating a terminal management table that associates an identifier of the connection terminal with the network identifier assigned to the connection terminal and a network identifier of the access point assigned to the connection terminal;

creating, by each of the PGW and the cloud LAN switch, a transfer table used for transferring a received packet with reference to the terminal management table;

determining, by each of the PGW and the cloud LAN switch, a transfer destination network with reference to the transfer table, by using a network identifier included in a received packet as a search key; and

transmitting, by each of the PGW and the cloud LAN switch, the packet to the network transfer destination network determined.

13. The communication method according to claim 12 , further comprising:

decapsulating, by the PGW, the first encapsulated packet when the packet forwarded in a communication channel of the mobile data transfer network or the cloud LAN is encapsulated;

referencing, by the PGW, to the transfer table, by using a network identifier extracted from the decapsulated packet as a search key;

determining, by the PGW, a network identifier of the packet transfer destination; and

encapsulating, by the PGW, the packet adapted to the network of the packet transfer destination, by using the identifier determined network.

14. The communication method according to claim 12 , further comprising:

referencing, by the PGW, to the transfer table, by using, as a search key, a network identifier corresponding to a destination of the first encapsulated packet from the cloud LAN;

upon finding that the network identifier corresponding to the destination is present in the transfer table; and

registering, by the PGW, the network identifier corresponding to the destination and a network identifier corresponding to a source of the first encapsulated packet in association with each other in the transfer table.

15. The communication system according to claim 12 , wherein the terminal management table includes

direct access information that specifies an entry to be registered with priority in the transfer table, wherein the method further comprises:

registering, by the PGW, with priority an entry with the direct access information attached thereto in the transfer table.

16. A non-transitory computer readable medium storing a program causing a computer to execute processing comprising:

configuring, as a cloud LAN (Local Area Network), a closed network constructed independently for each of a plurality of users in an open network, and generating an access point for accessing the cloud LAN, the access point assigned to each of a plurality of terminals that belong to the user using the cloud LAN;

selecting the access point assigned to a connection terminal, the connection terminal being a terminal accessing the cloud LAN via a mobile data transfer network, out of the plurality of terminals and notifying the connection terminal of the access point selected;

delivering an address for the connection terminal to access the cloud LAN in response to a request from the connection terminal;

generating a PGW (Packet Data Network Gateway) that serves as an access point between the mobile data transfer network and the cloud LAN, and a cloud LAN switch that performs switching of a packet forwarded on the cloud LAN;

receiving, by each of the PGW and the cloud LAN switch, a first encapsulated packet from either one of the mobile data transfer network and the cloud LAN;

extracting, by each of the PGW and the cloud LAN switch, a user packet from the first encapsulated packet received; and

converting, by each of the PGW and the cloud LAN switch, the user packet extracted to a second encapsulated packet adapted to the other one of the mobile data transfer network and the cloud LAN to transmit the second encapsulated packet thereto.