Reliable status delivery and request mechanism for static pseudowires

1. A method for determining peer status in a pseudowire (PW) node, the method comprising:

sending a first PW status request message to a peer node including a PW node local message ID, PW node remote message ID, and request flag;

starting a first retry timer, wherein a retry timer determines the interval at which PW status messages are sent;

starting a second retry timer when the first retry timer expires and no response to the first PW status request message is received;

starting a first request timer when the second retry timer expires and no response to the first PW status request message is received, wherein a request timer is one which determines the timeout interval if no response to a PW status request message is received; and

starting a third retry timer when the first request timer expires and no response to the first PW status request message is received.

2. The method of claim 1 , further comprising setting a PW node last request ID to the PW node local message ID when the first PW status request message is sent.

3. The method of claim 1 , further comprising initializing the PW node including randomly selecting the PW node local message ID, setting the PW node to an initial state, and starting a second request timer, wherein sending a first PW status request message to a peer node occurs after the second request timer expires.

4. The method of claim 3 , wherein the length of the second request timer is randomly selected.

5. The method of claim 1 , further comprising:

receiving a response to the first PW status request message from the peer node;

updating the PW node remote message ID with a peer node local message ID received in the response to the first PW status request message; and

updating a status of the PW node.

6. The method of claim 5 , further comprising restarting the first request timer.

7. The method of claim 5 , further comprising sending a second PW status request message to the peer node, if requested by the peer node, including the PW node local message ID, PW node remote message ID, and request flag.

8. The method of claim 7 , wherein the request flag is false.

9. A pseudowire (PW) node comprising:

a network interface;

a memory; and

a processor in communication with the memory, the processor being configured to:

send a first PW status request message to a peer node including a PW node local message ID, PW node remote message ID, and request flag;

start a first retry timer, wherein a retry timer determines the interval at which PW status messages are sent;

start a second retry timer when the first retry timer expires and no response to the first PW status request message is received;

start a first request timer when the second retry timer expires and no response to the first PW status request message is received, wherein a request timer is one which determines the timeout interval if no response to a PW status request message is received; and

start a third retry timer when the first request timer expires and no response to the first PW status request message is received.

10. The PW node of claim 9 , wherein the processor is further configured to set a PW node last request ID to the PW node local message ID when the first PW status message is sent.

11. The PW node of claim 9 , wherein the processor is further configured to initialize the PW node including randomly selecting the PW node local message ID, setting the PW node to an initial state, and starting a second request timer, wherein sending a first PW status request message to a peer node occurs after the second request timer expires.

12. The PW node of claim 11 , wherein the length of the second request timer is randomly selected.

13. The PW node of claim 9 , wherein the processor is further configured to:

receive a response to the first PW status request message from the peer node;

update the PW node remote message ID with a peer node local message ID received in the response to the first PW status request message; and

update a status of the PW node.

14. The PW node of claim 13 , wherein the processor is further configured to restart the first request timer.

15. The PW node of claim 13 , wherein the processor is further configured to send a second PW status request message to the peer node, if requested by the peer node, including the PW node local message ID, PW node remote message ID, and request flag.

16. The PW node of claim 13 , wherein the request flag is false.