Multicast heartbeat signaling
First Claim
1. A method of communication by a client over a network having plural servers, one of the servers assigned to receive messages from the client, the method comprising:
- listening for receipt of multicast heartbeats from any of the servers;
sending a message to the assigned server;
upon failure to receive a response to the message sent to the assigned server and failure to receive a heartbeat from the assigned server, selecting a second server from among the servers and re-sending the message to the second server.
1 Assignment
0 Petitions
Accused Products
Abstract
A mechanism that provides for communication of heartbeat signals from servers (call agents) to clients (gateways) in a packet telephony network environment. Clients listen for receipt of multicast heartbeats from any of the servers that may be part of a multicast group. A client assigned to a particular server for control messaging, upon failure to receive a response to a message sent to the assigned server and failure to receive a heartbeat from the assigned server, may select a second server from among the servers and re-send the message to the second server. Without receipt of heartbeat signals, the client defaults to a normal retry behavior for re-sending the message first to the assigned server a number of times before attempting to re-send the message to the second server. With receipt of the heartbeat from the second server, the client adopts an aggressive retry behavior by re-sending the message to the assigned server a lesser number of retries before attempting to re-send the message to the second server. The clients use the multicast heartbeats as a hint, allowing them to switch to the more aggressive retry behavior and consequently reduce the time to re-associate with a new server and re-establish a new security association (if IPsec is used), resulting in a drastic reduction in service delay due to server failures.
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Citations
32 Claims
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1. A method of communication by a client over a network having plural servers, one of the servers assigned to receive messages from the client, the method comprising:
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listening for receipt of multicast heartbeats from any of the servers;
sending a message to the assigned server;
upon failure to receive a response to the message sent to the assigned server and failure to receive a heartbeat from the assigned server, selecting a second server from among the servers and re-sending the message to the second server. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method of communication by a client over a network having a primary server and a backup server, the method comprising:
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establishing IPsec security association between the client and the primary server;
listening for receipt of multicast heartbeats, each having a source IP address and a payload that includes a server identifier;
sending a message to the IP address of the primary server;
upon receipt of one or more multicast heartbeats having the same source IP address as the IP address of the primary server and the server identifier of the backup server, and failure to receive a response to the message sent to the IP address of the primary server, re-establishing IPsec security association between the client and the backup server. - View Dependent Claims (10, 11, 12)
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13. A method of reducing service delay for a client over a network having a primary server and a backup server, the method comprising:
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monitoring the status of the primary server at the backup server;
upon failover of the primary server, starting transmission of multicast heartbeats from the backup server to the client; and
processing messages received from the client at the backup server. - View Dependent Claims (14, 15)
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16. A method of reducing service delay for a client over a network having plural servers, one of the servers assigned to receive messages from the client, the method comprising:
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sending multicast heartbeats from each of the servers to the client, each heartbeat including a preference value; and
upon failover of the assigned server, processing at one of the servers messages directed from the client based on the preference values. - View Dependent Claims (17)
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18. A client for communicating over a network having plural servers including an assigned server, the client comprising:
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a receiver that receives multicast heartbeats from any of the servers;
a transmitter that sends a message to the assigned server;
a heartbeat reception component that selects a second server from among the servers based on a preference value in a payload of the received heartbeat, the transmitter re-sending the message to the second server upon failure to receive a response to the message sent to the assigned server and failure to receive a heartbeat from the assigned server. - View Dependent Claims (19, 20, 21, 22)
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23. Apparatus for communicating over a network having plural servers including an assigned server, the apparatus comprising:
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means for listening for receipt of multicast heartbeats from any of the servers;
means for sending a message to the assigned server;
means for selecting a second server from among the servers and means for re-sending the message to the second server upon failure to receive a response to the message sent to the assigned server and failure to receive a heartbeat from the assigned server.
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24. Apparatus for communicating over a network having a primary server and a backup server, the apparatus comprising:
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means for establishing IPsec security association with the primary server;
means for listening for receipt of multicast heartbeats, each having a source IP address and a payload that includes a server identifier;
means for sending a message to the IP address of the primary server;
means for re-establishing IPsec security association with the backup server upon receipt of one or more multicast heartbeats having the same source IP address as the IP address of the primary server and the server identifier of the backup server, and failure to receive a response to the message sent to the IP address of the primary server.
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25. Apparatus for reducing service delay in a network having a primary server and a backup server, the apparatus comprising:
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means for monitoring the status of the primary server at the backup server;
means for starting transmission of multicast heartbeats from the backup server to the client and means for processing messages received from the client at the backup server upon failover of the primary server.
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26. Apparatus for reducing service delay for a client over a network having plural servers, one of the servers assigned to receive messages from the client, the apparatus comprising:
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means for sending multicast heartbeats from each of the servers to the client, each heartbeat including a preference value; and
means for processing at one of the servers messages directed from the client based on the preference values upon failover of the assigned server.
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27. A server for reducing service delay for clients over a network, the server comprising:
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a packet network interface for receiving messages from the clients; and
a heartbeat transmission component for sending multicast heartbeats periodically to the clients. - View Dependent Claims (28, 29)
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30. A backup server for reducing service delay for clients over a network that includes a primary server, the backup server comprising:
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a heartbeat transmission component that sends multicast heartbeats periodically to the clients upon a failover of the primary server; and
a packet network interface for receiving messages from the clients. - View Dependent Claims (31, 32)
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Specification