Network architecture and method of providing link protection in a bidirectional data traffic network

• US 6,813,241 B1
• Filed: 12/18/1999
• Issued: 11/02/2004
• Est. Priority Date: 12/18/1999
• Status: Expired due to Term

• Current Assignee: Ciena Corporation
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: Wang, Qinglin, Nathan, Sridhar Swami
• Primary Examiner(s): Olms, Douglas
• Assistant Examiner(s): Pizarro, Ricardo M.
• Application Number:
  US09/465,257
• Time in Patent Office: 1,781 Days
• Field of Search: 370/228, 370/225, 370/216, 370/217, 370/218, 370/219, 370/220, 370/221, 370/222, 370/223, 370/535, 370/536, 370/242, 370/241, 370/244, 370/250, 359/117, 359/128, 359/139, 359/110, 359/127, 385/16, 385/17
• US Class Current: 370/228
• 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 45/22 Alternate routing
• CPC Class Codes: H04L 45/28 using route fault recovery

Abstract

A network architecture for use in a data traffic network that includes a plurality of nodes and a plurality of data links coupling the nodes. The network architecture includes a working data link(220) that forms a signal pathway between a first router (200) and a second router (210) within the network. A protection data link(255) is likewise provided and forms a second signal pathway. The routers (200, 210) include both working data ports (312) and protection data ports (314) with each port including associated transmit and receive terminals. A combination of line splitting devices (250), line selection devices (260) and switch arrays (430, 435) are used to switch the flow of traffic data from the working data link (220) to the protection data link (255) or a protection channel (450) as is appropriate.

Claims

1. A data traffic network providing link protection between nodes in the network comprising:

a working data link forming a communications pathway between first and second nodes of said data traffic network;

first and second routing elements predisposed about said first and second nodes, respectively, and adapted to communicate data traffic over said working data link;

a signal splitting means disposed between said first routing element and said working data link;

a link selection means disposed between said second routing element and said working data link; and

a protection data link forming a signal path between said signal splitting means and said link selection means;

wherein said signal splitting means and link selection means are configured to protect the flow of traffic data between said first and second nodes by causing a switch from said working data link to said protection data link following the detection of a failure over said working data link, and

wherein said link selection means comprises;

an optical switch with first and second inputs and first and second outputs, said first and second inputs coupled to said working data link and protection data link, said first output utilized to communicate data traffic to said second routing element; and

an optical monitor communicably coupled to said second output of said optical switch and configured to determine the transmission qualities of said working data link and protection data link.

2. The data traffic network of claim 1 wherein each of said first and second routing elements further comprise a first short reach transmitter and a first short reach receiver for transmitting and receiving data traffic over and from said working data link or said protection data link.

3. The data traffic network of claim 2 further comprising:

a second short reach receiver and second short reach transmitter adapted to communicate with said first short reach transmitter and said first short reach receiver, respectively; and

a first long reach transmitter and a first long reach receiver adapted to communicate with said second short reach receiver and said second short reach transmitter, respectively, for providing a communications interface for data traffic transmitted and received by said first routing element over either said working data link or said protection data link.

4. The data traffic network of claim 2 further comprising:

a third short reach transmitter and a third short reach receiver adapted to provide communications between said second routing element and said link selection means; and

a second long reach transmitter and second long reach receiver adapted to communicate with said third short reach receiver and third short reach transmitter, respectively, and configured to provide a communications interface for data traffic transmitted and received by said second routing element over either said working data link or said protection data link.

5. The data traffic network of claim 1 wherein said optical monitor is configured to determine when said working data link has become suitable for carrying data traffic following the detection of a failure over said working data link.

6. The data traffic network of claim 1 wherein said optical monitor is configured to determine when said protection data link has failed and needs repair.

7. Within a data traffic network including a plurality of nodes and a plurality of data links coupling said nodes, a network architecture providing recovery from link and router component failures comprising:

a working data link forming a first signal pathway between a first node and a second node in the network;

a protection data link forming a second signal pathway between said first node and said second node;

first and second routers predisposed about said first and second nodes, respectively, and configured to transmit and receive data within said network, said routers including data ports and a first set of short reach transmitters and receivers for transmitting and receiving data traffic via said data ports;

a second set of short reach transmitter and receivers;

a third set of short reach transmitter and receivers;

first line splitting and line selection devices communicably coupled to said first router via said second set of short reach transmitters and receivers;

second line splitting and line selection devices communicably coupled to said second router via said third set of short reach transmitters and receivers;

first long reach transmitters and receivers disposed between said second set of short reach transmitters and receivers and said working and protection data links; and

second long reach transmitters and receivers disposed between said third set of short reach transmitters and receivers and said working and protection data links opposite said first long reach transmitters and receivers;

wherein said first and second line splitting devices and said first and second line selection devices are configured to switch between said data ports as well as said working and protection data links to ensure that a substantially uninterrupted signal path exists between said first and second nodes.

8. The network architecture of claim 7 wherein data ports further comprise working and protection data ports.

9. The network architecture of claim 7 wherein said first and second line selection devices each comprise:

a two-by-two switch having first and second inputs coupled to said working and protection data links, respectively, and first and second outputs, each of said first outputs coupled to a said first and second long reach receivers, respectively; and

a link monitor communicably coupled to said switch and configured to determine the transmission qualities of said working and protection data links.

10. The network architecture of claim 7 further comprising:

a protection channel providing a signal pathway between said first and second nodes;

first and second switching arrays providing a signal pathway for data traffic over said protection channel; and

a first splitter and a first selector, each respectively coupled to corresponding data ports of said first and second routers; and

a link extending from data ports of said first and second routers to said first and second switching arrays, respectively;

wherein said first and second switching arrays are configured to provide a bypass of data traffic from data ports of said first and second routers over said protection channel.

11. The network architecture of claim 10 further comprising:

first and second short reach transmitters and receivers communicable coupled to said first and second switching arrays for transmitting and receiving data traffic to and from said first and second routers, respectively;

first and second long reach transmitters and receivers communicably coupled to said first and second short reach transmitters and receivers, respectively, for transmitting and receiving said data traffic to and from said first and second short reach transmitters and receivers over said protection channel.

12. The network architecture of claim 10 wherein each of said first and second switching arrays are configured as a dual switch configuration for handling incoming and outgoing data traffic.

13. The network architecture of claim 12 wherein each of said dual switch configuration are communicably coupled to corresponding receive and transmit terminals of corresponding data ports of said first and second routers.

14. In a data traffic network comprising a plurality of routers and a plurality of communication links coupling said routers, said routers configured to select from said plurality of communication links to form working data links for the transmission of data traffic between nodes of the network, a network architecture providing protection against equipment or link failures so that data traffic can be routed from one node in the network to a second node in the network after the detection of such failures, the network architecture comprising:

a plurality of protection data links providing signal pathways between any two of said routers;

means of providing localized link protection between any two of said routers, said means configured to switch from a working data link to a protection data link after the detection of one or more failures on the working data link;

at least one protection channel providing a signal pathway between a first group of routers situated in one geographic location and a second group of routers situated within a second geographic location of said network; and

means of providing group protection for any router within said one or second geographic locations, said means configured to provide an alternate signal pathway for data traffic from any one of said first and second group of routers through said protection channel.

15. The network architecture of claim 14 said routers include a plurality of data ports adapted to support bi-directional communications for said routers, said data ports adapted as working data ports and protection data ports.

16. The network architecture of claim 14 wherein each of said means of providing localized link protection comprises:

a first line splitter with a first terminal coupled to corresponding protection data ports of said routers, and also comprising second and third terminals; and

a second switch with a first terminal coupled to said second terminal of said first line splitter for receiving data traffic from the corresponding router, and also comprising a second terminal coupled to said working data port of said corresponding router and a third terminal.

17. The network architecture of claim 16 further comprising corresponding links extending from each third terminal of said first line splitter to said means of providing group protection.

18. The network architecture of claim 16 further comprising short reach transmitters and receivers communicably coupled to said third terminals of said second switch for receiving and transmitting data over either said working data links or said protection data links.

19. The network architecture of claim 16 wherein each of said first line splitters is configured to direct data traffic either through said second switch or through said means of providing group protection following the detection of failures over either said working data links, said working data ports or protection data links.

20. The network architecture of claim 14 wherein each of said means of providing group protection comprises:

a first 1;

N switch array communicably coupled to said means of providing localized link protection for router in said first group, N representing the number of router ports in said first group;

a second 1;

N switch array communicably coupled to said means of providing localized link protection for routers in said second group, N representing the number of router ports in said second group.

21. The network architecture of claim 20 wherein said means of providing group protection further comprises:

first short reach transmitters and receivers configured to communicate with said means of providing link protection for routers in said first group;

second short reach transmitters and receivers configured to communicate with said means of providing link protection for routers in said second group;

first and second long reach transmitters and receivers configured to communicate traffic data received from both said first and second short reach transmitters and receivers over said protection channel.

22. In a data traffic network consisting of a plurality of routers and data links providing signal pathways between said routers, a method of protecting the communication of data traffic between any two of said routers in the event of failure, said method comprising the steps of:

(a) detecting when a failure occurs over a working data link utilized by at least two routers in said network;

(b) a set of link splitting and link selecting devices switching the flow of data traffic from said working data link to a protection data link; and

(c) the splitting and link selecting devices restoring the flow of data traffic from said protection data link to said working data link once a recovery of the working data link has occurred,

wherein said restoring step is performed by monitoring at said link selecting device the working data link to determine when it has recovered from the failure.

23. The method of claim 22 further comprising the step of providing a protection channel for carrying data traffic from a group of routers in a first geographic location to a group of routers in a second geographic location.

24. The method of claim 23 further comprising the step of directing data traffic from a data port of a router coupled to a failed working or protection data link to said protection channel.

25. The method of claim 24 wherein said step of directing is performed by switching a channel from said data port of said router to a switch array communicably coupled to said protection channel.