TUNNELING LOOP DETECTION CONTROL APPARATUS

• US 20090238080A1
• Filed: 10/30/2006
• Published: 09/24/2009
• Est. Priority Date: 10/28/2005
• Status: Active Grant

• Current Assignee: Panasonic Intellectual Property Corporation of America (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Ng, Chan Wah, Tan, Pek Yew, Hirano, Jun, Koh, Tien Ming Benjamin, Lim, Chun Keong Benjamin
• Granted Patent: US 7,969,892 B2
• Time in Patent Office: Days
• US Class Current: 370/241
• CPC Class Codes: H04L 12/4633 Interconnection of networks using encapsulation techniques, e.g. tunneling
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 45/18 Loop-free operations

Abstract

Disclosed is a technique whereby a tunnel entry point, which encapsulates a packet (generates a tunnel packet), can detect the presence of a tunneling loop causing a packet to loop the same path while encapsulated. According to this technique, upon receipt of a packet from a source node (source) 1100, TEP (tunnel entry point) 1120 inserts it into a tunnel packet header for encapsulation. Upon receipt of tunnel packets from TEP 1120 and TEP 1140, each of TEP 1140 and TEP 1160 copies the identifier of the original tunnel packet header to a new tunnel packet header for encapsulation. When this tunnel packet returns to TEP 1120 due to a tunneling loop, the tunneling loop is detected by referring to the identifier in the received tunnel packet.

Claims

1. A tunneling loop detection control apparatus so arranged that a tunneling loop detection identifier is added to a packet, which is to be transferred, for allowing a detection as to whether or not there is a tunneling loop with respect to a packet.

2. The tunneling loop detection control apparatus according to claim 1, comprising:

packet receiving means for receiving a packet;

packet encapsulating means for encapsulating said packet received by said packet receiving means to generate a tunnel packet;

identifier inserting means for, when said tunnel packet is generated by said packet encapsulating means, inserting said tunneling loop detection identifier, added, into a header of said tunnel packet; and

tunnel packet transmitting means for transmitting said tunnel packet generated by said packet encapsulating means.

3. The tunneling loop detection control apparatus according to claim 2, wherein unique information allocated to each communication equipment including the tunneling loop detection control apparatus is used as said tunneling loop detection identifier.

4. The tunneling loop detection control apparatus according to claim 3, wherein address information allocated to each communication equipment including the tunneling loop detection control apparatus, or a result of operation of a hash function relative to said address information, is used as said tunneling loop detection identifier.

5. The tunneling loop detection control apparatus according to claim 3, comprising:

identifier presence confirming means for confirming whether or not said tunneling loop detection identifier is present in a header of said packet received by said packet receiving means;

identifier insertion control means for, when the presence of said tunneling loop detection identifier is not confirmed by said identifier presence confirming means, controlling said identifier inserting means so that said unique information is inserted as said tunneling loop detection identifier;

identifier comparing means for, when the presence of said tunneling loop detection identifier is confirmed by said identifier presence confirming means, confirming whether or not said tunneling loop detection identifier in the header of said packet received by said packet receiving means is identical to said unique information;

error processing starting means for, when a result of the comparison in said identifier comparing means shows that said tunneling loop detection identifier in the header of said packet received by said packet receiving means is identical to said unique information, starting detection error processing on a tunneling loop; and

identifier duplication control means for, when a result of the comparison in said identifier comparing means shows that said tunneling loop detection identifier in the header of said packet received by said packet receiving means is not identical to said unique information, controlling said identifier inserting means so that said tunneling loop identifier included in the header of said packet received by said packet receiving means is inserted as said tunneling loop detection identifier into the header of said tunnel packet.

6. The tunneling loop detection control apparatus according to claim 3, comprising:

error message identifier comparing means for, when said packet received by said packet receiving means is an error message indicative of the fact that an upper limit of tunnel encapsulation has been exceeded, making a comparison as to whether or not a value of said tunneling loop detection identifier included in a header of a packet existing in a payload section of said error message agrees with a tunneling loop detection identifier stored in predetermined information storing means;

error processing starting means for, when a result of the comparison in said error message identifier comparing means shows that the value of said tunneling loop detection identifier included in the header of said packet existing in said payload section of said error message is identical to said tunneling loop detection identifier stored in said predetermined information storing means, starting detection error processing on a tunneling loop;

error message processing control means for, when the result of the comparison in said error message identifier comparing means shows that the value of said tunneling loop detection identifier included in the header of said packet existing in said payload section of said error message is not identical to said tunneling loop detection identifier stored in said predetermined information storing means, executing control so as to generate an error message including a packet corresponding to a packet existing in said payload section of said error message and included in a payload section of a packet existing in said payload section of said error message and further to store said tunneling loop identifier included in the header of said packet existing in said payload section of said error message in said predetermined information storing means; and

error message returning means for returning, to a destination of error notification, said error message generated by said error message generating means.

7. The tunneling loop detection control apparatus according to claim 3, comprising:

identifier presence confirming means for confirming whether or not said tunneling loop detection identifier is present in the header of said packet received by said packet receiving means;

identifier insertion control means for, when the presence of said tunneling loop detection identifier is not confirmed by said identifier presence confirming means, controlling said identifier inserting means so that said unique information is inserted as said tunneling loop detection identifier;

identifier comparing means for, when the presence of said tunneling loop detection identifier is confirmed by said identifier presence confirming means, confirming whether or not one of a plurality of information constituting said tunneling loop detection identifier in the header of said packet received by said packet receiving means is identical to said unique information;

error processing starting means for, when a result of the comparison in said identifier comparing means shows that one of said plurality of information constituting said tunneling loop detection identifier in the header of said packet received by said packet receiving means is identical to said unique information, starting detection error processing on a tunneling loop; and

identifier insertion control means for, when a result of the comparison in said identifier comparing means shows that all said plurality of information constituting said tunneling loop detection identifier in the header of said packet received by said packet receiving means do not agree with said unique information, controlling said identifier inserting means so that a tunneling loop detection identifier is organized with said tunneling loop identifier included in the header of said packet received by said packet receiving means and said unique information so as to insert the newly organized tunneling loop detection identifier as said tunneling loop detection identifier into the header of said tunnel packet.

8. The tunneling loop detection control apparatus according to claim 2, wherein different information for each of said tunnel packets generated by said packet encapsulating means is used as said tunneling loop detection identifier.

9. The tunneling loop detection control apparatus according to claim 8, comprising numeric value generating means for generating a numeric value to be used as said different information for each of said tunnel packets at random or according to a predetermined sequence.

10. The tunneling loop detection control apparatus according to claim 8, comprising:

identifier presence confirming means for confirming whether or not said tunneling loop detection identifier is present in the header of said packet received by said packet receiving means;

identifier insertion control means for, when the presence of said tunneling loop detection identifier is not confirmed by said identifier presence confirming means, controlling said identifier inserting means so that different information for each of said tunnel packets is inserted as said tunneling loop detection identifier;

identifier comparing means for, when the presence of said tunneling loop detection identifier is confirmed by said identifier presence confirming means, confirming whether or not said tunneling loop detection identifier in the header of said packet received by said packet receiving means agrees with a tunneling loop detection identifier stored in said predetermined information storing means;

error processing starting means for, when a result of the comparison in said identifier comparing means shows that said tunneling loop detection identifier in the header of said packet received by said packet receiving means agrees with said tunneling loop detection identifier stored in said predetermined information storing means, starting detection error processing on a tunneling loop; and

identifier duplication control means for, when a result of the comparison in said identifier comparing means shows that said tunneling loop detection identifier in the header of said packet received by said packet receiving means do not agree with said tunneling loop detection identifier stored in said predetermined information storing means, controlling said identifier inserting means so that said tunneling loop identifier included in the header of said packet received by said packet receiving means is inserted as said tunneling loop detection identifier into the header of said tunnel packet and said tunneling loop identifier included in the header of said packet received by said packet receiving means is stored in said predetermined information storing means.

11. The tunneling loop detection control apparatus according to claim 10, comprising memory control means for executing control so that, when a predetermined period of time elapses from the storage, said tunneling loop detection identifier stored in said predetermined information storage means is released from said predetermined information storage means.

12. The tunneling loop detection control apparatus according to claim 2, wherein information obtained by a combination of a static portion including unique information allocated to each communication equipment including the tunneling loop detection control apparatus and a dynamic portion including different information for each of said tunnel packets generated by said packet encapsulating means is used as said tunneling loop detection identifier.

13. The tunneling loop detection control apparatus according to claim 12, wherein address information allocated to each communication equipment including the tunneling loop detection control apparatus or a result of operation of a hash function relative to said address information is used as said static portion.

14. The tunneling loop detection control apparatus according to claim 13, comprising numeric value generating means for generating a numeric value to be used as said different information for each of said tunnel packets at random or according to a predetermined sequence.

15. The tunneling loop detection control apparatus according to claim 12, comprising:

identifier presence confirming means for confirming whether or not said tunneling loop detection identifier is present in a header of said packet received by said packet receiving means;

identifier insertion control means for, when the presence of said tunneling loop detection identifier is not confirmed by said identifier presence confirming means, controlling said identifier inserting means so that information obtained by a combination of said unique information and different information for each of said tunnel packets is inserted as said tunneling loop detection identifier;

static identifier comparing means for, when the presence of said tunneling loop detection identifier is confirmed by said identifier presence confirming means, confirming whether or not a static portion of said tunneling loop detection identifier in the header of said packet received by said packet receiving means agrees with said unique information;

identifier comparing means for, when the presence of said tunneling loop detection identifier is confirmed by said identifier presence confirming means, confirming whether or not said tunneling loop detection identifier in the header of said packet received by said packet receiving means agrees with a tunneling loop detection identifier stored in said predetermined information storing means;

error processing starting means for, when a result in one of said static identifier comparing means and said identifier comparing means shows the agreement therewith, starting detection error processing on a tunneling loop; and

identifier duplication control means for, when both the results in said static identifier comparing means and said identifier comparing means do not show the agreement, controlling said identifier inserting means so that said tunneling loop identifier included in the header of said packet received by said packet receiving means is inserted as said tunneling loop detection identifier into the header of said tunnel packet and said tunneling loop identifier included in the header of said packet received by said packet receiving means is stored in said predetermined information storing means.

16. The tunneling loop detection control apparatus according to claim 15, comprising memory control means for executing control so that, when a predetermined period of time elapses from the storage, said tunneling loop detection identifier stored in said predetermined information storage means is released from said predetermined information storage means.