Communications system and related method for reducing continuity check message (CCM) bursts in connectivity fault management (CFM) maintenance association (MA)
View Patent ↗In accordance with a non-limiting example, a system and method minimizes collisions between transmitted connectivity fault management (CFM) packets. Maintenance association endpoints are formed from a plurality of network switch elements to form a maintenance association. The clocks between each network switch element within the maintenance association are synchronized. A unique transmission window is assigned to each maintenance association endpoint as part of the maintenance association. A respective CFM packet is transmitted as a continuity check message (CCM) within the unique transmission window.
1. A communications system comprising:
a plurality of Maintenance Association End Points (MEP) arranged to form a Maintenance Association within the Maintenance Association have a clock synchronized with other respective clocks; and
each MEP having a unique transmission window in the Maintenance Association to transmit from the MEP a respective Connectivity Fault Management (CFM) packet as a multicast Continuity Check Message (CCM).
2. The communications system according to claim 1 , wherein each clock is synchronized using a Network Time Protocol.
3. The communications system according to claim 1 , wherein a respective MEP is configured to determine a transmission window by dividing the CFM packet interval by the maximum number of MEP/s in the Maintenance Association.
4. The communications system according to claim 1 , wherein a local MEP is configured to have a unique transmission window at which it is the only MEP in the Maintenance Association transmitting a CCM.
5. The communications system according to claim 1 , wherein a MEP is configured to use an identifier as an index to a list of transmission windows and use the transmission window as an offset against a synchronized timing source.
6. The communications system according to claim 5 wherein a MEP is configured to apply an offset against a base timing value of a clock.
7. The communications system according to claim 1 , wherein a MEP is configured to determine a transmission window by ordering identifiers of the MEP's in a list and determining which transmission window to use based on the ordering of the MEP identifiers.
8. The communications system according to claim 7 wherein a MEP is configured to order the identifiers for MEP's in a list and determining which transmission window to use based on an MEP identifier in the list.
9. A method comprising:
synchronizing a clock of a network switch element configured as a Maintenance Association End Point (MEP) with clocks of other MEP's within a Maintenance Association;
assigning the MEP a unique transmission window in the Maintenance Association; and
transmitting from the MEP a Connectivity Fault Management (CFM) packet as a Continuity Check Message (CCM) within the unique transmission window.
10. The method according to claim 9 , and further comprising synchronizing the clock using a Network Time Protocol.
11. The method according to claim 9 , and further comprising determining the unique transmission window by dividing the CFM packet interval by the maximum number of MEP's in the Maintenance Association.
12. The method according to claim 9 , and further comprising assigning a unique transmission window to the MEP at which it is the only MEP in the Maintenance Association transmitting a CCM.
13. The method according to claim 9 , the MEP using an identifier as an index to a list of transmission windows and using the unique transmission window as an offset against a synchronized timing source.
14. The method according to claim 13 , and further comprising applying an offset against a base timing value of a clock.
15. The method according to claim 9 , and further comprising determining the unique transmission window by ordering identifiers of the MEP's in a list and determining which transmission window to use based on the ordering of the MEP identifiers.
16. The method according to claim 15 , and further comprising ordering the identifiers for MEP's in a list and determining which transmission window to use based on an MEP identifier in the list.
17. A device, comprising:
a network switch element configured as a Maintenance Association End Point (MEP), the MEP operable to form a Maintenance Association with a plurality of other MEP's;
the MEP comprising a clock and operable to synchronize the clock with other respective clocks in the Maintenance Association and to determine a unique transmission window in the Maintenance Association to transmit from the MEP a Connectivity Fault Management (CFM) packet as a multicast Continuity Check Message (CCM).
18. The device of claim 17 , wherein the clock is synchronized using a Network Time Protocol.
19. The device of claim 17 , wherein the MEP is configured to determine the unique transmission window by dividing the CFM packet interval by the maximum number of MEP/s in the Maintenance Association.
20. The device of claim 17 , wherein the MEP is configured to use an identifier as an index to a list of unique transmission windows and use the unique transmission window as an offset against a synchronized timing source.
21. The device of claim 20 , wherein the MEP is configured to apply an offset against a base timing value of the clock.
22. The device of claim 17 , wherein the MEP is configured to determine the unique transmission window by ordering identifiers of the MEP's in a list and to determine which unique transmission window to use based on the ordering of the MEP identifiers.
23. The device of claim 22 , wherein the MEP is configured to order the identifiers for MEP's in a list and to determine which unique transmission window to use based on an MEP identifier in the list.