COMMUNICATION SYSTEM AND COMMUNICATION NODE

• US 20090022161A1
• Filed: 02/01/2006
• Published: 01/22/2009
• Est. Priority Date: 02/04/2005
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Hirano, Jun
• Granted Patent: US 7,751,413 B2
• Time in Patent Office: Days
• US Class Current: 370/400
• CPC Class Codes: H04L 45/26 Route discovery packet
• CPC Class Codes: H04L 69/16 Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP]
• CPC Class Codes: H04W 28/26 Resource reservation
• CPC Class Codes: H04W 36/0016 Hand-off preparation specially adapted for end-to-end data sessions
• CPC Class Codes: H04W 40/36 due to handover
• CPC Class Codes: H04W 80/04 Network layer protocols, e.g. mobile IP [Internet Protocol]

Abstract

A technique is disclosed, by which it is possible to identify a communication node having special function under the condition that a certain communication node knows only the address of a communication node having no special function. According to this technique, a first communication node 10 having a first function (e.g. the mounting of IPv6 and ICMPv6) and a second function (e.g. the mounting of NSIS) transmits a search packet by an echo request packet of ICMPv6 with the purpose of searching a communication node having the first function and the second function to a second communication node 20 having only the first function. The second communication node sends back a response packet to this by an echo response packet of ICMPv6. A communication node 15 having the first function and the second function and being the first receiver of this response packet grasps that own communication node is the search object of the first communication node. Also, by the search packet, desired information can be offered from the first communication node to the communication node of the search object.

Claims

1. A communication system, comprising at least a first communication node, having a first function to realize transfer of a packet, and a second function, being an additional function different from said first function, and a second communication node having said first function, and said first communication node grasps address of said second communication node, wherein:

said first communication node transmits a search packet to said second communication node for the purpose of searching a communication node having said first function and said second function;

said second communication node transmits a response packet including said predetermined information in response to the receiving of said search packet; and

a third communication node, having said first function and said second function and being a first receiver of said response packet, grasps that it is a search object of said first communication node upon receipt of said response packet.

2. The communication system according to claim 1, wherein said search packet is transferred without modifying the packet from said first communication node to said second communication node, and after said second communication has received said search packet transmitted from said first communication node as it is, it is arranged that said response packet is transmitted, which has source address of said search packet as destination address.

3. The communication system according to claim 2, wherein said third communication node discards said response packet and generates and transmits a notifying packet including address of said third communication node to said destination address of said response packet.

4. The communication system according to claim 2, wherein said third communication node inserts address of said third communication node into said response packet and transmits said response packet.

5. The communication system according to claim 4, wherein the communication node having said first function and said second function to transfer said response packet transfers the response packet as it is without modifying the packet when said response packet with the address of said third communication node inserted therein is received.

6. The communication system according to claim 1, wherein the communication node having said first function and said second function, which transfers said search packet from said first communication node to said second communication node, is arranged to transfer by rewriting source address of said search packet to address of own communication node, said second communication node has address of said communication node, having said first function and said second function as rewritten immediately before reaching said second communication node, as a source address, and after said search packet having address of said first communication node in a predetermined region has been received, the source address of said search packet is transmitted, which has source address of said search packet as destination address.

7. The communication system according to claim 6, wherein said third communication node has the address of said first communication node included in said response packet as destination address, and generates and transmits a notifying packet including address of said third communication node.

8. The communication system according to claim 1, wherein said first communication node inserts desired information into payload of said search packet, and said second communication node includes said desired information in the payload of said search packet into the payload of said response packet without changing so that said desired information is offered from said first communication node transmitting said search packet to said third communication node, which receives said response packet.

9. The communication system according to claim 1, wherein a movable mobile node transmits a search request of a communication node having said first function and said second function including at least the address of said second communication node to said first communication node, and said first communication node generates and transmits said search packet upon receipt of said search request.

10. The communication system according to claim 1, wherein said first function is realized by the mounting of IPv6 and ICMPv6, and said search packet and said response packet are an echo request packet and an echo response packet of ICMPv6 respectively.

11. The communication system according to claim 1, wherein said second function is realized by the mounting of NSIS, and a communication node mounted with NSIS and being the first receiver of said response packet to be transmitted from said second communication node is searched by said first communication node.

12. A communication node having a first function to realize transfer of packet and having a second function being an additional function different from said first function, wherein said communication node comprises:

address grasping means for grasping address of a predetermined communication node having said first function;

searching means for generating and transmitting a search packet having address of said predetermined communication node as destination address with the purpose of searching a communication node having said first function and said second function; and

address acquiring means for acquiring address of a communication node having said first function and said second function by receiving a notifying packet containing the address of a communication node having said first function and said second function, said communication node being the first receiver of a response packet transmitted as a response to said search packet by said predetermined communication node, or by receiving said response packet containing the address of the communication node having said first function and said second function, said communication node being the first receiver of said response packet.

13. The communication node according to claim 12, wherein said searching means inserts desired information into payload of said search packet so that said predetermined communication node offers said desired information included in payload of said response packet to a communication node having said first function and said second function, said communication node being a first receiver of said response packet, and said desired information being the information contained in payload of said search packet as it is.

14. The communication node according to claim 12, wherein said communication node comprises search request receiving means for receiving a search request of a communication node having said first function and said second function at least including address of said predetermined communication node from a movable mobile node, and for generating and transmitting said search packet based on the receiving of said search request.

15. A communication node having a first function to realize transfer of packet and having a second function being an additional function different from said first function, wherein said communication node comprises:

packet transfer means for transferring a packet;

search packet detecting means for detecting a search packet transmitted from a first communication node to a second communication node with the purpose for searching a communication node having said first function and said second function; and

packet modifying means for rewriting source address of said search packet to address of own communication node when said search packet has been detected by said search packet detecting means.

20. The communication node according to claim 15, wherein said first function is fulfilled by the mounting of IPv6 and ICMPv6, and said search packet and said response packet are arranged to be an echo request packet and an echo response packet of ICMPv6 respectively.

22. The communication node according to claim 15, wherein said second function is fulfilled by the mounting of NSIS, and a communication node is searched, which is mounted with NSIS and is the first receiver of said response packet transmitted from said predetermined communication node.

16. A communication node having a first function to realize transfer of packet and having a second function being an additional function different from said first function, wherein said communication node comprises:

packet transfer means for transferring a packet; and

response packet detecting means for grasping that own communication node is a search object of said first communication node by detecting a response packet to the search packet, said search packet being transmitted from a first communication node to a second communication node with the purpose of searching a communication node having said first function and said second function.

17. The communication node according to claim 16, wherein said communication node comprises address notifying means for generating and transmitting a notifying packet having address of said first communication node contained in said response packet as destination address and including address of own communication node.

18. The communication node according to claim 17, wherein said communication node comprises response packet discarding means for discarding said response packet.

19. The communication node according to claim 16, wherein said communication node comprises:

address insertion detecting means for detecting whether or not address of another communication node having said first function and said second function is inserted in a predetermined region in said response packet;

address inserting means for inserting address of own communication node in a predetermined region in said response packet when it has been detected at said address insertion detecting means that address of said another communication node is not inserted; and

said response packet where address of said another communication node is inserted is transferred when it is detected that address of said another communication node is not inserted at said address insertion detecting means, and said response packet is transferred without modifying the packet when it is detected that address of said another communication node is inserted at said address insertion detecting means.

21. The communication node according to claim 16, wherein said first function is fulfilled by the mounting of IPv6 and ICMPv6, and said search packet and said response packet are arranged to be an echo request packet and an echo response packet of ICMPv6 respectively.

23. The communication node according to claim 16, wherein said second function is fulfilled by the mounting of NSIS, and a communication node is searched, which is mounted with NSIS and is the first receiver of said response packet transmitted from said predetermined communication node.