Retaining active operations, administration, and maintenance (OAM) sessions across multiple devices operating as a single logical device

1. A logical Network Interface Device (NID) comprising:

a first NID connected to a peer NID; and

a second NID connected to the peer NID and communicatively coupled to the first NID, wherein the first NID and the second NID are each connected to a network element for redundant communication to the peer NID,

wherein the first NID actively operates an active maintenance endpoint in an Operations, Administration, and Maintenance (OAM) session with the peer NID, and wherein the active maintenance endpoint synchronizes OAM session data with a dormant maintenance endpoint at the second NID, and wherein the first NID and the second NID each separately maintains an OAM session database of the OAM session data,

wherein the active maintenance endpoint and the dormant maintenance endpoint have the same configuration, are configured to invoke a session generator with the peer NID simultaneously, and are configured to maintain respective OAM session databases with the OAM session data such that the peer NID is configured to operate the OAM session transparently with either one based on protection such that the peer NID is unaware of which of the first NID and the second NID is the active maintenance endpoint.

2. The logical NID of claim 1 , wherein the dormant maintenance endpoint becomes the active maintenance endpoint responsive to a protection switch, and wherein the dormant maintenance endpoint has the OAM session data in a database based on synchronization with the first NID.

3. The logical NID of claim 1 , wherein the active maintenance endpoint synchronizes with the dormant maintenance endpoint by providing copies of OAM Protocol Data Units (PDUs).

4. The logical NID of claim 1 , wherein the active maintenance endpoint synchronizes with the dormant maintenance endpoint by providing relevant information from OAM Protocol Data Units (PDUs).

5. The logical NID of claim 1 , wherein the active maintenance endpoint performs one or more of a generator function, a collector function, and a reflector function, each configured to provide data to the dormant maintenance endpoint.

6. The logical NID of claim 1 , wherein the OAM session data relates to any of continuity checks, loopbacks, linktrace, delay measurements, and packet loss measurements.

7. A Network Interface Device (NID) comprising:

a first port connected to a peer NID over a network;

a second port connected to a network element;

a communications interface connected to a second NID, wherein the second NID is also connected to the peer NID and the network element to provide redundancy; and

circuitry configured to

operate an active maintenance endpoint in an Operations, Administration, and Maintenance (OAM) session with the peer NID, and

synchronize OAM session data with a dormant maintenance endpoint at the second NID, via the communications interface, and wherein the NID and the second NID each separately maintains an OAM session database of the OAM session data,

wherein the active maintenance endpoint and the dormant maintenance endpoint have the same configuration, are configured to invoke a session generator with the peer NID simultaneously, and are configured to maintain respective OAM session databases with the OAM session data such that the peer NID is configured to operate the OAM session transparently with either one based on protection such that the peer NID is unaware of which of the first NID and the second NID is the active maintenance endpoint.

8. The NID of claim 7 , wherein the circuitry is further configured to

switch the active maintenance endpoint to the dormant maintenance endpoint responsive to a protection switch, and

synchronize the OAM session data from the active maintenance endpoint now at the second NID.

9. The NID of claim 7 , wherein the active maintenance endpoint synchronizes with the dormant maintenance endpoint by providing copies of OAM Protocol Data Units (PDUs).

10. The NID of claim 7 , wherein the active maintenance endpoint synchronizes with the dormant maintenance endpoint by providing relevant information from OAM Protocol Data Units (PDUs).

11. The NID of claim 7 , wherein the active maintenance endpoint performs one or more of a generator function, a collector function, and a reflector function, each configured to provide data to the dormant maintenance endpoint.

12. The NID of claim 7 , wherein the OAM session data relates to any of continuity checks, loopbacks, linktrace, delay measurements, and packet loss measurements.

13. A method comprising:

in a first Network Interface Device (NID), operating an active maintenance endpoint in an Operations, Administration, and Maintenance (OAM) session with a peer device in a network; and

synchronizing OAM session data with a dormant maintenance endpoint at a second NID, wherein the first NID and the second NID are each connected to a network element for redundant communication to the peer NID, and wherein the first NID and the second NID each separately maintains an OAM session database of the OAM session data,

wherein the active maintenance endpoint and the dormant maintenance endpoint have the same configuration, are configured to invoke a session generator with the peer NID simultaneously, and are configured to maintain respective OAM session databases with the OAM session data such that the peer NID is configured to operate the OAM session transparently with either one based on protection such that the peer NID is unaware of which of the first NID and the second NID is the active maintenance endpoint.

14. The method of claim 13 , further comprising

switching the active maintenance endpoint to the dormant maintenance endpoint responsive to a protection switch; and

synchronizing the OAM session data from the active maintenance endpoint now at the second NID.

15. The method of claim 13 , wherein the active maintenance endpoint synchronizes with the dormant maintenance endpoint by providing copies of OAM Protocol Data Units (PDUs).

16. The method of claim 13 , wherein the active maintenance endpoint synchronizes with the dormant maintenance endpoint by providing relevant information from OAM Protocol Data Units (PDUs).

17. The method of claim 13 , wherein the active maintenance endpoint performs one or more of a generator function, a collector function, and a reflector function, each configured to provide data to the dormant maintenance endpoint.