Active/static path redundancy

Patent metadata

Field	Value
Publication number	US-9503361-B2
Application number	US-201414303875-A
Country	US
Kind code	B2
Filing date	Jun 13, 2014
Priority date	Jun 13, 2014
Publication date	Nov 22, 2016
Grant date	Nov 22, 2016

Abstract

Delivering every packet of a stream simultaneously along two different paths gives a high assurance that the destination will receive at least one of them, even if a single failure occurs. The present idea uses the topology protocols to know when to regenerate a dual stream after one failure occurs, so that the dual delivery, and thus assurance against further failures, is maintained.

First claim

What is claimed is:

1. A method comprising:
establishing a plurality of paths capable of transmitting a stream of data packets from a source network device to a destination network device, the plurality of paths operating on a reserved bandwidth network;
replicating a first data packet in the stream of data packets at the source network device such that one copy of the data packet is transmitted on each of the plurality of paths;
recognizing a failure of a first network device on a first path of the plurality of paths;
notifying each network device of the plurality of paths of the failure of the first network device;
replicating the data stream at a designated network device on a second path which does not contain the first network device;
providing the replicated data stream to a second network device on the first path, wherein the destination device receives the stream of data packets from the first path containing the first network device and the second path containing the designated network device;
bringing the first network device up from the failure; and
discarding received data packets at the first network device until the first network device receives a continue message from the second network device.

2. The method of claim 1 , further comprising discontinuing receipt at the second device of data packets sent from the designated network device after the first network device is brought up from failure.

3. The method of claim 2 , further comprising transmitting the continue message from the second network device to the first network device.

4. The method of claim 3 , further comprising continuation of normal operation of the path containing the first network device upon receipt of the continue message.

5. The method of claim 1 , wherein notifying each network device of the failure of the first network device comprises notifying using an intermediate system to intermediate system (ISIS) protocol.

6. The method of claim 1 , wherein replicating the data stream at the designated network device comprises wherein replicating the data stream at the designated network device in response to receiving the notification of the failure of the first network device.

7. The method of claim 1 , wherein providing the replicated data stream to the second network device on the first path comprises providing the replicated data stream over an intermediate path connecting the designated network device and the second device.

8. The method of claim 1 , wherein providing the replicated data stream over an intermediate path comprises providing the replicated data stream over a preconfigured intermediate path.

9. The method of claim 1 , wherein providing the replicated data stream to the second network device on the first path comprises providing the replicated data stream over an emergency path connecting the designated network device and the second device.

10. A system comprising:
a source network device;
a destination network device;
a first data path connecting the source device and the destination device, the first path comprising a first designated network device; and
a second data path connecting the source device and the destination device, the second path comprising a second designated device;
wherein the first data path and the second data path operate on a reserved bandwidth network;
wherein the source device is configured to:
replicate a first data packet in a stream of data packets;
transmit the first data packet on the first data path;
transmit the replicated first data packet on the second data path;

wherein the system is configured to:
detect a failure of a first network device on the first path;
notify each network device of the system of the failure of the first network device;
replicate the data stream at the second designated network device;
provide the replicated data stream to a second network device located on the first path;
bring the first network device up from the failure; and
discard received data packets at the first network device until the first network device receives a continue message from the second network device.

11. The system of claim 10 , wherein the system being configured to provide the replicated data stream to the second network device comprises the system being configured to provide the replicated data stream to the second network device on an intermediate path.

12. The system of claim 11 , wherein the intermediate path is an emergency path.

13. The system of claim 10 , wherein the destination node is configured to receive the first data packet and the replicated data packet.

14. The system of claim 10 , wherein the system being configured to notify each network device of the failure of the first network device comprises the system being configured to notify using an intermediate system to intermediate system (ISIS) protocol.

15. The system of claim 10 , wherein the continue message is transmitted from the second network device to the first network device.

16. The system of claim 10 , wherein the system is further configured to continue normal operation of the first path upon receipt of the continue message.

17. An apparatus comprising:
a memory storage; and
a processing unit coupled to the memory storage, wherein the processing unit is operative to:
establish a plurality of paths capable of transmitting a stream of data packets from a source network device to a destination network device, the plurality of paths operating on a reserved bandwidth network;
replicate a first data packet in the stream of data packets at the source network device such that one copy of the data packet is transmitted on each of the plurality of paths;
recognize a failure of a first network device on a first path of the plurality of paths;
notify each network device of the plurality of paths of the failure of the first network device;
replicate the data stream at a designated network device on a second path which does not contain the first network device;
provide the replicated data stream to a second network device on the first path, wherein the destination device receives the stream of data packets from the first path containing the first network device and the second path containing the designated network device;
bring the first network device up from the failure; and
discard received data packets at the first network device until the first network device receives a continue message from the second network device.

18. The apparatus of claim 17 , wherein the processing unit is further operative to transmit the continue message from the second network device to the first network device.

19. The apparatus of claim 17 , wherein the processing unit is further operative to continue of normal operation of the path containing the first network device upon receipt of the continue message.

Assignees

• Cisco Tech Inc

Inventors

• Finn Norman W

Classifications

• H04L69/14

  Multichannel or multilink protocols · CPC title

• H04L69/40

  for recovering from a failure of a protocol instance or entity, e.g. service redundancy protocols, protocol state redundancy or protocol service redirection (management of faults, events, alarms or notifications in data switching networks H04L41/06) · CPC title

• H04L41/0668 Primary

  by dynamic selection of recovery network elements, e.g. replacement by the most appropriate element after failure · CPC title

• H04L45/28 Primary

  using route fault recovery · CPC title

• H04L45/24

  Multipath · CPC title