Patent ID: 7969892

Claim:
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 said packet, said tunneling loop detection control apparatus comprising: a packet receiving unit for receiving said packet; a packet encapsulating unit for encapsulating said packet received by said packet receiving unit to generate a tunnel packet; an identifier inserting unit for, when said tunnel packet is generated by said packet encapsulating unit, inserting said tunneling loop detection identifier into a header of said tunnel packet; a tunnel packet transmitting unit for transmitting said tunnel packet generated by said packet encapsulating unit; and a loop detecting unit for confirming whether or not a same packet as said tunnel packet has already been received based on said tunneling loop detection identifier in a header of said packet received by said packet receiving unit, and starting detection error processing on the tunneling loop when the packet has already been received, wherein unique information allocated to each piece of communication including the tunneling loop detection control apparatus is used as said tunneling loop detection identifier, and wherein said loop detecting unit comprises: an identifier presence confirming unit for confirming whether or not said tunneling loop detection identifier is present in the header of said packet received by said packet receiving unit; an identifier insertion control unit for, when the presence of said tunneling loop detection identifier is not confirmed by said identifier presence confirming unit, controlling said identifier inserting unit so that said unique information is inserted as said tunneling loop detection identifier; an identifier comparing unit for, when the presence of said tunneling loop detection identifier is confirmed by said identifier presence confirming unit, confirming whether or not said tunneling loop detection identifier in the header of said packet received by said packet receiving unit is identical to said unique information; an error processing starting unit for, when a result of the comparison in said identifier comparing unit shows that said tunneling loop detection identifier in the header of said packet received by said packet receiving unit is identical to said unique information, starting said detection error processing on said tunneling loop; and an identifier duplication control unit for, when a result of the comparison in said identifier comparing unit shows that said tunneling loop detection identifier in the header of said packet received by said packet receiving unit is not identical to said unique information, controlling said identifier inserting unit so that said tunneling loop detection identifier included in the header of said packet received by said packet receiving unit is inserted as said tunneling loop detection identifier into the header of said tunnel packet.