COMMUNICATION APPARATUS, METHOD EXECUTED BY COMMUNICATION APPARATUS, AND STORAGE MEDIUM STORING SOFTWARE FOR EXECUTING METHOD

• US 20090116499A1
• Filed: 03/29/2007
• Published: 05/07/2009
• Est. Priority Date: 03/29/2006
• Status: Active Grant

• Current Assignee: Redwood Technologies, LLC (Dominion Harbor Enterprises, LLC)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Kokado, Takeshi
• Granted Patent: US 7,839,807 B2
• Time in Patent Office: Days
• US Class Current: 370/401
• CPC Class Codes: H04L 12/2838 Distribution of signals within a home automation network, e.g. involving splitting/multiplexing signals to/from different paths adaptations of television systems for transmission by electric cable for domestic distribution H04N7/106; hybrid transport H04L12/6418; home network arrangements specially adapted for distribution of digital video signals H04N7/24
• CPC Class Codes: H04L 45/02 Topology update or discovery
• CPC Class Codes: H04L 45/20 Hop count for routing purposes, e.g. TTL
• CPC Class Codes: H04L 61/5092 by self-assignment, e.g. picking addresses at random and testing if they are already in use

Abstract

A communication apparatus which is capable of performing bi-directional communication via a router in a local network including one or more routers is provided. An upper segment determination section (421) obtains address range information under an upper router which is connected on an external network side of a router to which the communication apparatus is connected. A terminal communication path holding section (425) connects and holds a communication path to another communication apparatus in the local network. A message relay section (424) relays a communication message from the other communication apparatus. When the terminal communication path holding section (425) receives a first request message requesting to establish a communication path from the other communication apparatus, the terminal communication path holding section (425) stores source address information of the received first request message, and transmit a response message to the stored source address information to establish a communication path to the other communication apparatus.

Claims

1. A communication apparatus connected to a local network connected to an external network in which local network one or more routers are connected in series between a communication apparatus in the local network and the external network, the communication apparatus connecting a communication path to another communication apparatus in the local network, the communication apparatus having a relay function to relay a communication message from said another communication apparatus, the communication apparatus comprising:

an upper segment determination section for obtaining and storing address range information which indicates an address range within which an address, of a communication apparatus under an upper router which is connected in the local network and connected on an external network side of a router to which the communication apparatus is connected, is capable of being set;

a terminal communication path holding section for connecting and holding a communication path to another communication apparatus in the local network; and

a message relay section for relaying a communication message from said another communication apparatus, wherein

when the terminal communication path holding section receives a first request message requesting to establish a communication path from said another communication apparatus, the terminal communication path holding section stores source address information of the received first request message, transmits a response message to the stored source address information, and establishes a communication path to said another communication apparatus,

when the terminal communication path holding section does not receive the first request message from said another communication apparatus, the terminal communication path holding section presumes address information of another communication apparatus under the upper router using the address range information stored by the upper segment determination section, transmits a second request message requesting to establish a communication path to the presumed address information, and receives a response message to establish a communication path to said another communication apparatus under the upper router and to store address information of said communication apparatus to which the communication path has been established, and

the message relay section has a relay function to receive a communication message from said another communication apparatus, to take out destination information which is described in the received communication message and designated by said another communication apparatus, to obtain address information corresponding to the destination information from the address information stored by the terminal communication path holding section, and to transmit the received communication message to the obtained address information.

2. The communication apparatus according to claim 1, wherein the upper segment determination section obtains LAN-side address information or LAN-side address information and WAN-side address information of one or more routers among routers located between the router to which the communication apparatus is connected and the external network, presumes an address range within which an address of another communication apparatus which is connected to a first network to which the obtained address information belongs is capable of being set, and stores the presumed address range as the address range information.

3. The communication apparatus according to claim 1, further comprising:

a relay function search section for searching for another communication apparatus which exists in the local network and has a relay function; and

a search response section for transmitting a response for a search message which is received from another communication apparatus in the local network, wherein

the relay function search section obtains an address which can be set to another communication apparatus having a relay function using the address information stored by the terminal communication path holding section, transmits a search message to the address, and receives a response message from said another communication apparatus having the relay function, thereby finding said another communication apparatus having the relay function,

only when the relay function search section does not find said another communication apparatus having the relay function, the relay function search section activates the terminal communication path holding section and the message relay section, and the search response section responds to a search message which is received from another communication apparatus in the local network, and

when the relay function search section finds said another communication apparatus having the relay function, the relay function search section inactivates the terminal communication path holding section and the message relay section, and the search response section does not respond to a search message which is received from another communication apparatus in the local network.

4. The communication apparatus according to claim 3, further comprising a sever communication path holding section for connecting and holding a communication path to another communication apparatus having a relay function, wherein

when the relay function search section finds another communication apparatus having a relay function, the sever communication path holding section transmits a first request message requesting to establish a communication path to said another communication apparatus having the relay function, and receives a response message to establish a communication path to said another communication apparatus having the relay function, and

when the relay function search section does not find another communication apparatus having a relay function, if the sever communication path holding section receives a first request message requesting to establish a communication path from another communication apparatus having a relay function, the sever communication path holding section transmits a response message to a source of the received first request message to establish a communication path to said another communication apparatus having the relay function.

5. The communication apparatus according to claim 3, wherein when the sever communication path holding section detects an abnormality of communication with said another communication apparatus having the relay function, the relay function search section re-executes a search for another communication apparatus having a relay function, and activates the server communication path holding section, the message relay section, and the search response section in accordance with a result of the search.

6. The communication apparatus according to claim 4, wherein

when the relay function search section does not find another communication apparatus having a relay function, the sever communication path holding section monitors whether or not the sever communication path holding section receives a first request message requesting to establish a communication path from another communication apparatus having a relay function for a predetermined time period, and

when the sever communication path holding section does not receive the first request message, the sever communication path holding section activates the terminal communication path holding section and the message relay section, and the search response section responds to a search message which is received from another communication apparatus in the local network.

7. The communication apparatus according to claim 1, wherein when the terminal communication path holding section and the message relay section are activated, an address which matches an address within a predetermined range is selected from addresses which are not currently used as a host address in a subnetwork, and is set to the communication apparatus.

8. The communication apparatus according to claim 1, wherein when the terminal communication path holding section receives address information of another communication apparatus to which a communication path has not been connected yet from said another communication apparatus to which the communication path has been established through the communication path, the terminal communication path holding section transmits a second request message requesting to establish a communication path based on the received address information.

9. The communication apparatus according to claim 1, further comprising input means for a user to input a signal to the communication apparatus, wherein

the upper segment determination section determines whether or not to obtain address range information under the upper router in accordance with the signal from the input means, and

the terminal communication path holding section determines whether or not to transmit a second request message requesting to establish a communication path to another communication apparatus under the upper router in accordance with the signal from the input means.

10. The communication apparatus according to claim 1, further comprising input means for a user to input a signal to the communication apparatus, wherein

the terminal communication path holding section determines, in accordance with the signal from the input means, whether or not to transmit a response message when the terminal communication path holding section receives a first request message requesting to establish a communication path from said another communication apparatus.

11. A communication apparatus connected to a local network connected to an external network in which local network one or more routers are connected in series between a communication apparatus in the local network and the external network, the communication apparatus connecting a communication path to another communication apparatus in the local network which has a relay function, the communication apparatus performing message communication with another communication apparatus via said another communication apparatus having the relay function, the communication apparatus comprising:

an upper segment determination section for obtaining and storing address range information which indicates an address range within which an address, of a communication apparatus under an upper router which is connected in the local network and connected on an external network side of a router to which the communication apparatus is connected, is capable of being set; and

a sever communication path holding section for connecting a communication path to said another communication apparatus having the relay function, wherein

the sever communication path holding section presumes address information of said another communication apparatus having the relay function based on the address range information stored by the upper segment determination section, transmits a first request message requesting to establish a communication path to the presumed address information, and receives a response message from said another communication apparatus having the relay function to establish the communication path, and

when the sever communication path holding section receives a second request message requesting to establish a communication path from said another communication apparatus having the relay function, the sever communication path holding section transmits a response message to a source address of the second request message to establish a communication path to said another communication apparatus having the relay function.

12. The communication apparatus according to claim 11, wherein the sever communication path holding section transmits address information of another communication apparatus to which said another communication apparatus having the relay function has not connected a communication path yet to said another communication apparatus having the relay function through the communication path which is established to said another communication apparatus having the relay function.

13. The communication apparatus according to claim 11, wherein when the sever communication path holding section detects an abnormality of communication with said another communication apparatus having the relay function, the upper segment determination section re-executes processing of obtaining and storing the address range information, and the sever communication path holding section re-executes processing of establishing a communication path to said another communication apparatus having the relay function.

14. The communication apparatus according to claim 11, further comprising input means for a user to input a signal to the communication apparatus, wherein

the upper segment determination section determines whether or not to obtain address range information under the upper router in accordance with the signal from the input means, and

the sever communication path holding section determines whether or not to transmit a first request message requesting to establish a communication path to another communication apparatus under the upper router in accordance with the signal from the input means.

15. The communication apparatus according to claim 11, further comprising input means for a user to input a signal to the communication apparatus, wherein

the sever communication path holding section determines, in accordance with the signal from the input means, whether or not to transmit a response message when the sever communication path holding section receives a second request message requesting to establish a communication path from said another communication apparatus having the relay function.

16. A method executed by a communication apparatus connected to a local network connected to an external network in which local network one or more routers are connected in series between a communication apparatus in the local network and the external network, the communication apparatus connecting a communication path to another communication apparatus in the local network, the communication apparatus having a relay function to relay a communication message from said another communication apparatus, the method comprising:

an upper segment determination step of obtaining and storing address range information which indicates an address range within which an address, of a communication apparatus under an upper router which is connected in the local network and connected on an external network side of a router to which the communication apparatus is connected, is capable of being set;

a terminal communication path holding step of connecting and holding a communication path to another communication apparatus in the local network; and

a message relay step of relaying a communication message from said another communication apparatus, wherein

when a first request message requesting to establish a communication path is received from said another communication apparatus, at the terminal communication path holding step, source address information of the received first request message is stored, a response message is transmitted to the stored source address information, and a communication path is established to said another communication apparatus,

when the first request message is not received from said another communication apparatus, at the terminal communication path holding step, address information of another communication apparatus under the upper router is presumed using the address range information stored by the upper segment determination step, a second request message requesting to establish a communication path is transmitted to the presumed address information, and a response message is received to establish a communication path to said another communication apparatus under the upper router and to store address information of said another communication apparatus to which the communication path has been established, and

the message relay step has a relay function to receive a communication message from said another communication apparatus, to take out destination information which is described in the communication message and designated by said another communication apparatus, to obtain address information corresponding to the destination information from the address information stored by the terminal communication path holding step, and to transmit the received communication message to the obtained address information.

18. A storage medium storing software for executing a method according to claim 16.

17. A method executed by a communication apparatus connected to a local network connected to an external network in which local network one or more routers are connected in series between a communication apparatus in the local network and the external network, the communication apparatus connecting a communication path to another communication apparatus in the local network which has a relay function, the communication apparatus performing message communication with another communication apparatus via said another communication apparatus having the relay function, the method comprising:

an upper segment determination step of obtaining and storing address range information which indicates an address range within which an address, of a communication apparatus under an upper router which is connected in the local network and connected on an external network side of a router to which the communication apparatus is connected, is capable of being set; and

a server communication path holding step of connecting a communication path to said another communication apparatus having the relay function, wherein

at the server communication path holding step, address information of said another communication apparatus having the relay function is presumed based on the address range information stored by the upper segment determination step, a first request message requesting to establish a communication path is transmitted to the presumed address information, a response message is received from said another communication apparatus having the relay function to establish a communication path, and

when a second request message requesting to establish a communication path is received from said another communication apparatus having the relay function, at the server communication path holding step, a response message is transmitted to a source address of the second request message to establish a communication path to said another communication apparatus having the relay function.

19. A storage medium storing software for executing a method according to claim 17.