End-to-end notification of local protection using OAM protocol
View Patent ↗An end-to-end monitoring mechanism whereby edge nodes are notified that a particular path flows through a local protection tunnel along the way. The notification mechanism utilizes OAM packets which include a link protection indication that are transmitted on the Ethernet service layer. The link protection indication may be represented by one or more flags to indicate that local protection is in place along the path. The mechanism enables fast local protection to be used with slower end-to-end protection by informing the latter when local protection is activated. In an implementation in which local-protection does not preserve the CIR of the protected traffic, the invention provides minimal interruption of Committed Information Rate (CIR) connections by minimizing the time traffic is diverted through local protection tunnels. Notification of the edge node that local protection is in use occurs very quickly, thus allowing the edge node to rapidly switch to a backup path.
1. A method of end-to-end notification of local protection in a network for use on an intermediate node along a path in said network, said method comprising the steps of:
receiving end-to-end protocol packets sent from a first edge node to a second edge-node;
identifying received end-to-end protocol packets to be forwarded to a local protection tunnel due to a failure in said network; and
setting a link protection indication in end-to-end protocol packets to be sent over said local protection tunnel, said link protection indication adapted to notify an end node of said path that local protection has been activated in said network.
2. The method according to claim 1 , wherein said end-to-end protocol comprises an Operation, Administration and Maintenance (OAM) protocol.
3. The method according to claim 1 , wherein said end-to-end protocol packets comprise Ethernet packets.
4. The method according to claim 1 , wherein said end-to-end protocol packets comprise Multiprotocol Label Switching (MPLS) packets.
5. The method according to claim 1 , wherein said link-protection indication comprises a single-bit flag.
6. The method according to claim 1 , wherein said local protection tunnel comprises Multi-Protocol Label Switching (MPLS) protection tunnel.
7. The method according to claim 1 , further comprising the step of limiting the bandwidth provisioned for high priority traffic to less than half the total link bandwidth.
8. The method according to claim 1 , wherein no bandwidth is provisioned for local protection in said network.
9. The method according to claim 1 , further comprising the step of redirecting traffic from said path which is protected by a local protection tunnel to a backup path within 2 seconds of said failure.
10. The method according to claim 1 , further comprising the step of ceasing to set said link protection indication in said end-to-end protocol packets when redirection to a local protection tunnel ceases.
11. The method according to claim 1 , wherein said step of identifying comprises recognizing an Operation, Administration and Maintenance (OAM) destination MAC address in said end-to-end protocol packet.
12. The method according to claim 1 , wherein said step of identifying comprises recognizing an Operation, Administration and Maintenance (OAM) Multiprotocol Label Switching (MPLS) label in said end-to-end protocol packet.
13. A method of monitoring the availability of a path in a network, said method comprising the steps of:
generating and sending operation, administration and maintenance (OAM) packets end-to-end on a path in said network;
receiving OAM packets on an intermediate node; and
identifying received OAM packets directed to a protection path and setting a link protection flag in said identified OAM packets in response thereto, said link protection flag adapted to notify an end node of said path that local protection has been activated in said network.
14. The method according to claim 13 , wherein said OAM packets comprise Ethernet packets.
15. The method according to claim 13 , wherein said OAM packets comprise Multiprotocol Label Switching (MPLS) packets.
16. The method according to claim 13 , wherein said protection tunnel comprises Multi-Protocol Label Switching (MPLS) protection tunnel.
17. The method according to claim 13 , further comprising the step of limiting the bandwidth provisioned for high priority traffic to less than half the total link bandwidth.
18. The method according to claim 13 , wherein no bandwidth is provisioned for local protection in said network.
19. The method according to claim 13 , further comprising the step of ceasing to set said link protection flag in said OAM packets when redirection to a local protection tunnel ceases.
20. The method according to claim 13 , wherein said step of identifying comprises recognizing an OAM destination MAC address in said OAM packet.
21. The method according to claim 13 , wherein said step of identifying comprises recognizing an Operation, Administration and Maintenance (OAM) Multiprotocol Label Switching (MPLS) label said OAM packet.
22. A method of end-to-end notification of local protection in a network for use in a first edge node in communication with a second edge node along a path in said network, said method comprising the steps of:
receiving operation, administration and maintenance (OAM) packets comprising a link protection bit set by an intermediate node in the event said OAM packet is directed through a local protection tunnel due to a failure in said network;
identifying received OAM packets having said link protection bit set indicating that said path has been routed through a local protection tunnel; and
redirecting traffic destined to said second edge node over a backup path in response to said link protection bit being set.
23. The method according to claim 22 , wherein said OAM packets comprise Ethernet packets.
24. The method according to claim 22 , wherein said local protection tunnel comprises Multi-Protocol Label Switching (MPLS) protection tunnel.
25. The method according to claim 22 , further comprising the step of limiting the bandwidth provisioned for high priority traffic to less than half the total link bandwidth.
26. The method according to claim 22 , wherein no bandwidth is provisioned for local protection in said network.
27. The method according to claim 22 , wherein said link protection bit ceases to be set in said OAM packets when redirection to a local protection tunnel stops.
28. The method according to claim 22 , wherein said step of identifying comprises recognizing an OAM destination MAC address in said OAM packet.
29. A network processor for use in an intermediate network node located along a path in a network, comprising:
means for receiving end-to-end protocol packets sent from an edge node;
means for identifying received end-to-end protocol packets destined to a local protection tunnel due to a failure in said network; and
means for setting a link protection flag in end-to-end protocol packets to be sent over said local protection tunnel, said link protection flag adapted to notify an end node of said path that local protection has been activated in said network.
30. The network processor according to claim 29 , wherein said end-to-end protocol packets comprise operation, administration and maintenance (OAM) packets.
31. The network processor according to claim 29 , wherein said OAM packets comprise availability-monitoring protocol packets.
32. The network processor according to claim 29 , wherein said means for identifying is adapted to recognize an Operation, Administration and Maintenance (OAM) destination MAC address in said OAM packet.
33. The network processor according to claim 29 , adapted to be implemented in an Application Specific Integrated Circuit (ASIC).
34. The network processor according to claim 29 , adapted to be implemented in a Field Programmable Gate Array (FPGA).
35. A network device for use in an intermediate network node located along a path in a network, comprising:
one or more line PHY line interfaces for interfacing said network device to one or more communication links;
a switch adapted to switch data between a plurality of ingress inputs and a plurality of egress outputs;
processing means operative to:
receive operation, administration and maintenance (OAM) packets sent from an edge node;
identify received OAM packets destined to a local protection tunnel due to a failure in said network; and
set a link protection indication in OAM packets to be sent over said local protection tunnel, said link protection indication adapted to notify an end node of said path that local protection has been activated in said network.
36. The network device according to claim 35 , wherein said processing means is operative to identify received OAM packets by recognizing an OAM destination MAC address in said OAM packet.
37. The network device according to claim 35 , adapted to be implemented in an Application Specific Integrated Circuit (ASIC).
38. The network device according to claim 35 , adapted to be implemented in a Field Programmable Gate Array (FPGA).
39. A network device for use in a first edge node in communication with a second edge node along a path in said network, comprising:
one or more PHY line interfaces for interfacing said network device to one or more communication links;
a switch adapted to switch data between a plurality of ingress inputs and a plurality of egress outputs;
processing means operative to:
receive operation, administration and maintenance (OAM) packets comprising a link protection indication set by an intermediate node in the event said OAM packet is directed through a local protection tunnel due to a failure in said network;
identify received OAM packets having said link protection indication set indicating that said path has been routed through a local protection tunnel; and
redirect traffic destined to said second edge node over a backup path in response to said link protection indication being set.
40. The network device according to claim 39 , wherein said processing means is operative to identify received OAM packets by recognizing an OAM destination MAC address in said OAM packet.
41. The network device according to claim 39 , adapted to be implemented in an Application Specific Integrated Circuit (ASIC).
42. The network device according to claim 39 , adapted to be implemented in a Field Programmable Gate Array (FPGA).
43. A computer program product for use in a network device, said computer program product comprising:
a computer useable medium having computer readable program code means embodied in said medium for performing a path reroute in a network, said computer program product comprising:
computer readable program code means for receiving operation, administration and maintenance (OAM) packets sent from an edge node;
computer readable program code means for identifying received OAM packets destined to a local protection tunnel due to a failure in said network; and
computer readable program code means for setting a link protection flag in OAM packets to be sent over said local protection tunnel, said link protection flag adapted to notify an end node of said path that local protection has been activated in said network.