Communication system, node device, communication method in the communication system, and program

A node device comprising a controller configured to:

• detect a failure on a first transmission path over which data transmission is being performed;
• when said failure exists in a link or a node that is located immediately before its own node, set a single second transmission path as far as a transmission terminal node, said second transmission path that excludes a path from the transmission terminal node to a node that has detected said failure within said first transmission path;
• transmit a first failure notification signal as far as said transmission terminal node over said second transmission path;
• and
• upon receipt of said first failure notification signal, switch a switch instantly for data transmission so that a path for new data transmission is the same path as a transmission path for said first failure notification signal, wherein
• when said second transmission path overlaps with part of said first transmission path, transmit a second failure notification signal, different from the first notification signal, to one or more downstream nodes over said first transmission path, and
• upon receipt of said second failure notification signal at a junction node where overlapping between the first transmission path and the second transmission ends, transmit said first failure notification signal from the junction node over said second transmission path.

A communication method in a communication system comprising:

• detecting a failure on a first transmission path over which data transmission is being performed;
• when said failure exists in a link or a node that is located immediately before its own node, setting a single second transmission path as far as a transmission terminal node, said second transmission path that excludes a path from said transmission terminal node to a node that has detected said failure within said first transmission path;
• transmitting a first failure notification signal as far as said transmission terminal node over said second transmission path;
• upon receipt of said first failure notification signal, switching a switch instantly for data transmission so that a path for new data transmission is the same path as a transmission path for said first failure notification signal;
• and
• upon said transmission terminal node receiving said failure notification signal, switching said switch to said second transmission path and performing a new data transmission over said second transmission path, wherein
• when said second transmission path overlaps with part of said first transmission path, transmitting a second failure notification signal, different from the first notification signal, to one or more nodes located downstream of said first transmission path, and
• upon receipt of said second failure notification signal at a junction node where overlapping between the first transmission path and the second transmission ends transmitting said first failure notification signal from the junction node over said second transmission path.

A non-transitory computer readable medium embedded with a computer program product comprising computer executable code, which when executed, causes a computer to execute:

• detecting a failure on a first transmission path over which data transmission is being performed;
• when said failure exists in a link or a node that is located immediately before its own node, setting a single second transmission path as far as a transmission terminal node, said second transmission path that excludes a path from said transmission terminal node to a node that has detected said failure within said first transmission path;
• transmitting a failure notification signal as far as said transmission terminal node over said second transmission path;
• upon receipt of said failure notification signal, switching a switch instantly for data transmission so that a path for new data transmission is the same path as a transmission path for said failure notification signal;
• and
• upon said transmission terminal node receiving said failure notification signal, switching said switch to said second transmission path and performing a new data transmission over said second transmission path, wherein
• when said second transmission path overlaps with part of said first transmission path, transmitting a second failure notification signal, different from the first notification signal, to one or more nodes located downstream of said first transmission path, and
• upon receipt of said second failure notification signal at a junction node where overlapping between the first transmission path and the second transmission ends, transmitting said first failure notification signal from the junction node over said second transmission path.