End-to-end bidirectional keep-alive using virtual circuits
First Claim
1. A system for providing keep-alive detection between end nodes of a virtual circuit in a data network, the system comprising:
- a virtual circuit including a first end node, a second end node and at least one intermediate router;
said first end node being coupled to a first router of said at least one intermediate router;
said second end node being coupled to a second router of said at least one intermediate router, said second end node further being coupled to said first end node via said virtual circuit;
said virtual circuit being represented by an associated data link connection identifier (DLCI) other than that used by a local management interface, and configured to allow transmission of data frames between said first and second end nodes;
said first end node including a first keep-alive mechanism configured to send at least one keep-alive REQUEST message to said second end node via said virtual circuit; and
said second end node including a second keep-alive mechanism configured to respond to reception of said at least one keep-alive REQUEST message by sending at least one keep-alive REPLY message to said first end node via said virtual circuit.
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Accused Products
Abstract
The invention provides a method and system for sending and receiving end-to-end bidirectional keep-alive messages using virtual circuits. Nodes coupled to a network, such as a frame relay network, periodically exchange link-layer “keep-alive” messages which indicate information regarding configuration and status of the virtual circuit, as well as information regarding congestion at sending nodes. Nodes respond to received keep-alive messages, or to timed-out failure to receive keep-alive messages, with follow-on actions, such as attempting to reconnect when a virtual circuit fails. Keep-alive messages may be propagated across multiple networks of either similar or different architecture. Keep-alive messages include sent and received sequence numbers, thus providing receiving nodes with a technique for determining if any keep-alive messages have been lost. Keep-alive messages can also include information regarding configuration of the virtual circuit, status of the virtual circuit (including counts of recent keep-alive message failure or success), and congestion at the sending node.
209 Citations
47 Claims
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1. A system for providing keep-alive detection between end nodes of a virtual circuit in a data network, the system comprising:
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a virtual circuit including a first end node, a second end node and at least one intermediate router;
said first end node being coupled to a first router of said at least one intermediate router;
said second end node being coupled to a second router of said at least one intermediate router, said second end node further being coupled to said first end node via said virtual circuit;
said virtual circuit being represented by an associated data link connection identifier (DLCI) other than that used by a local management interface, and configured to allow transmission of data frames between said first and second end nodes;
said first end node including a first keep-alive mechanism configured to send at least one keep-alive REQUEST message to said second end node via said virtual circuit; and
said second end node including a second keep-alive mechanism configured to respond to reception of said at least one keep-alive REQUEST message by sending at least one keep-alive REPLY message to said first end node via said virtual circuit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
wherein said at least one keep-alive REQUEST message and said at least one keep-alive REPLY message each include a respective field having a predetermined value which may be used for identifying the frame as a keep-alive message.
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12. A method for providing keep-alive detection between end nodes of a virtual circuit in a data network, the method comprising:
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sending, via the virtual circuit, at least one keep-alive REQUEST message from a first end node to a second end node of the virtual circuit, said first end node including a keep-alive mechanism for detecting a failure of communication with said second end node, said virtual circuit being identified by an associated data link connection identifier (DLCI) other than that used by a local management interface, and configured to allow transmission of data frames between said first and second end nodes; and
waiting for receipt of a keep-alive REPLY message from said second end node via said virtual circuit. - View Dependent Claims (13, 14, 15, 16, 17)
receiving at said second end node, via said virtual circuit, said at least one keep-alive REQUEST message; and
responding to said at least one keep-alive REQUEST message by sending at least one keep-alive REPLY message over said virtual circuit to said first end node.
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17. The method of claim 12 wherein the data network is a frame relay network.
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18. A system for providing keep-alive detection between end nodes of a virtual circuit in a data network, the system comprising:
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means for sending, via the virtual circuit, at least one keep-alive REQUEST message from a first end node to a second end node of the virtual circuit, said first end node including a keep-alive mechanism for detecting a failure of communication with said second end node, said virtual circuit being identified by an associated data link connection identifier (DLCI) other than that used by a local management interface, and configured to allow transmission of data frames between said first and second end nodes; and
means for waiting for receipt of a keep-alive REPLY message from said second end node via said virtual circuit. - View Dependent Claims (24)
a request receive mechanism configured to receive said at least one keep-alive REQUEST message from said second node; and
a send reply mechanism configured to send said at least one keep-alive REPLY message to the request receive mechanism in response to receiving said at least one keep-alive REQUEST message.
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19. An end node coupled to one or more routers which are part of a virtual circuit of a frame relay network, said end node including:
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a keep-alive mechanism including;
a send mechanism configured to send at least one keep-alive REQUEST message over the virtual circuit, said virtual circuit being represented by an associated data link connection identifier (DLCI) other than that used by a local management interface, and configured to allow transmission of data frames between end nodes of the virtual circuit; and
a reply receive mechanism configured to receive, via said virtual circuit, a keep-alive REPLY message, responsive to said at least one keep-alive REQUEST message. - View Dependent Claims (20, 21, 22, 23, 25)
a keep-alive receive mechanism in communication with said send mechanism via said virtual circuit, said at least one keep-alive receive mechanism including;
a request receive mechanism configured to receive said at least one keep-alive REQUEST message from the first end node; and
a send reply mechanism configured to send said at least one keep-alive REPLY message responsive to the request receive mechanism.
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23. The node of claim 22, wherein said second end node includes a second keep-alive mechanism.
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25. The node of claim 19, wherein said at least one keep-alive REQUEST message and said at least one keep-alive REPLY message comprise link-level protocol messages.
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26. A method for determining a health status of a communication link in a data network, the communication link providing a communication path between a first end node and a second end node, the communication link including at least one data channel for transmission of data frames between the first and second end nodes, the communication link further including at least one signaling channel utilizing at least one local management interface for transmitting state information relating to the at least one data channel, the method comprising:
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sending, via the at least one data channel, at least one keep-alive REQUEST message from the first end node to the second end node, said first end node including a keep-alive mechanism for detecting a failure of communication with said second end node; and
waiting for receipt of a keep-alive REPLY message from said second end node via said at least one data channel. - View Dependent Claims (27, 28, 29, 30, 31, 32)
receiving at said second end node, via said at least one data channel, said at least one keep-alive REQUEST message; and
responding to said at least one keep-alive REQUEST message by sending at least one keep-alive REPLY message over said at least one data channel to said first end node.
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32. The method of claim 26 wherein the data network is a frame relay network and wherein the at least one data channel is a virtual circuit.
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33. A method for determining a health status of a communication link in a data network, the communication link providing a communication path between a first end node and a second end node, the communication link including at least one data channel for transmission of data frames between the first and second end nodes, the communication link further including at least one signaling channel utilizing at least one local management interface for transmitting state information relating to the at least one data channel, the method comprising:
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receiving, via said at least one data channel, at said second end node, a plurality of keep-alive REQUEST messages, at least one of said keep-alive REQUEST messages being sent from a first end node, said at least one keep-alive REQUEST message being used by the first node to detect a failure of communication with the second end node; and
responding to each received keep-alive REQUEST message by sending a respective keep-alive REPLY message to said first end node over said at least one data channel. - View Dependent Claims (34, 35, 36)
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37. An end node coupled a communication link in a data network, the communication link providing a communication path between the first end node and a second end node, the communication link including at least one data channel for transmission of data frames between the first and second end nodes, the communication link further including at least one signaling channel utilizing at least one local management interface for transmitting state information relating to the at least one data channel, the end node comprising:
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a send mechanism configured to send, via the at least one data channel, at least one keep-alive REQUEST message to the second end node;
a receive mechanism configured to detect a receipt of a keep-alive REPLY message from said second end node via said at least one data channel; and
a keep-alive mechanism for detecting a failure of communication with said second end node. - View Dependent Claims (38, 39, 40, 41, 42, 43)
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44. An end node coupled a communication link in a data network, the communication link providing a communication path between the first end node and a second end node, the communication l ink including at least one data channel for transmission of data frames between the first and second end nodes, the communication link further including at least one signaling channel utilizing at least one local management interface for transmitting state information relating to the at least one data channel, the end node comprising:
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a receive mechanism configured or designed to receive, via said at least one data channel, a plurality of keep-alive REQUEST messages, at least one of said keep-alive REQUEST messages being sent from said second end node, said at least one keep-alive REQUEST message being used by the second node to detect a failure of communication with the first end node; and
a response mechanism configured or designed to respond to each received keep-alive REQUEST message by sending a respective keep-alive REPLY message to said first end node via said at least one data channel. - View Dependent Claims (45, 46, 47)
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Specification