System and method for path failure recovery in a communications environment
View Patent ↗Provided are a system and method for recovering from failure of a path connecting first and second nodes in a communications network. In one example, the method includes identifying that the path has failed. Contexts affected by the path failure are deleted on the first node, and the second node with which the path was shared is notified that the contexts have been deleted.
1. A communications system configured for recovering from path failure between nodes, the system comprising:
first and second nodes connected by a link;
a processor accessible to the first node;
a memory accessible to the processor; and
a plurality of instructions stored on the memory and executable by the processor, the instructions including:
instructions for determining that the link has failed;
instructions for deleting at least one Packet Data Protocol (PDP) context associated with the link on the first node;
instructions for updating a value on the first node to indicate that the at least one PDP context has been deleted, wherein the value is associated with the link; and
instructions for sending the updated value to the second node to indicate to the second node that the at least one PDP context has been deleted.
2. The system of claim 1 , wherein the system includes a wireless network supporting General Packet Radio Service (GPRS) and wherein the nodes are GPRS support nodes.
3. The system of claim 1 , wherein the value is a restart value in a restart counter.
4. The system of claim 3 , wherein the restart value is stored in non-volatile memory in the first node.
5. The system of claim 1 further comprising instructions for execution by a processor associated with the second node, the instructions comprising:
instructions for receiving the updated value from the first node;
instructions for storing the updated value; and
instructions for deleting at least one shared context on the second node, wherein the at least one shared context corresponds to the at least one PDP context deleted on the first node.
6. The system of claim 5 , wherein the updated value is stored in volatile memory in the second node.
7. The system of claim 5 , wherein the at least one shared context is deleted on the second node only if the second node has not already identified that the path has failed and deleted the at least one shared context before receiving the updated value from the first node.
8. A method for path failure recovery, the method comprising:
providing a gateway serving node (GSN) on each end of a data path connection;
providing a local non-volatile recovery counter on a per path basis on each GSN;
providing a local volatile recovery counter on a per path basis on each GSN, the local volatile recovery counter containing a recovery counter last received from the GSN on the other end of the data path in a response message;
incrementing the local non-volatile recovery counter in response to messages transmitted from one GSN to the GSN on the other end of the data path, the local non-volatile recovery counter for indicating to the GSN on the other end of the data path that at least one Packet Data Protocol (PDP) context on the data path have been deleted by the GSN transmitting the response message;
deleting the at least one PDP context associated with the data path in response to the recovery counter received in a response message being not equal to the local volatile recovery counter associated with the data path; and
storing the recovery counter received in the response message in the local volatile recovery counter associated with the data path on the GSN.
9. The method of claim 8 wherein the at least one PDP context is deleted due to path failure.
10. The method of claim 8 wherein the at least one PDP context is deleted due to path restart.
11. The method of claim 8 wherein a GSN informs peer GSNs that the at least one PDP context has been deleted due to path failure.