Abstract: In a multi-protocol label system (MPLS) carrying data, a working path carries data from a starting point or node to a destination point or node via a working path. The working path includes the switches and physical media linking starting point and the destination point. MPLS system reliability is enhanced by way of a protection path, over which data can be carried from the starting point to the destination point upon a detected failure along the working path. Upstream messages inform one or more MPLS switching systems to make a switchover from a working path to a protection path.

Abstract: Recovery time upon the failure of a link or switching system in an asynchronous data network can be minimized if downstream data switches provide upstream messages indicating to upstream switching system that the downstream traffic arrived in tact and was properly handled. Upon this loss or failure of the upstream status message to an upstream switching system, an upstream switching system can reroute data traffic around a failed link or failed switch with a minimal amount of lost data. The upstream status message is conveyed from a downstream switching system to an upstream switching system via a reverse notification tree data pathway. The reverse notification pathway is established by using a messaging protocol between network switches by which the working and protection paths, among other things, are established.

Abstract: Recovery time upon the failure of a link or switching system in an asynchronous data network can be minimized if downstream data switches provide upstream messages indicating to an upstream switching system that the downstream traffic arrived intact and was properly handled. Upon this loss or failure of the upstream status message to an upstream switching system, an upstream switching system can reroute data traffic around a failed link or failed switch with a minimal amount of lost data. The upstream status message is conveyed from a downstream switching system to an upstream switching system via a reverse notification tree data pathway.

Abstract: Recovery time upon the failure of a link or switching system in an asynchronous data network can be minimized if downstream data switches provide upstream messages indicating to upstream switching system that the downstream traffic arrived in tact and was properly handled. Upon this loss or failure of the upstream status message to an upstream switching system, an upstream switching system can reroute data traffic around a failed link or failed switch with a minimal amount of lost data. The upstream status message is conveyed from a downstream switching system to an upstream switching system via a reverse notification tree data pathway.

Abstract: Recovery time upon the failure of a link or switching system in an asynchronous data network can be minimized if downstream data switches provide upstream messages indicating to upstream switching system that the downstream traffic arrived in tact and was properly handled. Upon this loss or failure of the upstream status message to an upstream switching system, an upstream switching system can reroute data traffic around a failed link or failed switch with a minimal amount of lost data. The upstream status message is conveyed from a downstream switching system to an upstream switching system via a reverse notification tree data pathway.

Abstract: Recovery time upon the failure of a link or switching system in an asynchronous data network can be minimized if downstream data switches provide upstream messages indicating to upstream switching system that the downstream traffic arrived in tact and was properly handled. Upon this loss or failure of the upstream status message to an upstream switching system, an upstream switching system can reroute data traffic around a failed link or failed switch with a minimal amount of lost data. The upstream status message is conveyed from a downstream switching system to an upstream switching system via a reverse notification tree data pathway.

Abstract: In a multi-protocol label system (MPLS) carrying data, a working path carries data from a starting point or node to a destination point or node via a working path. The working path includes the switches and physical media linking starting point and the destination point. MPLS system reliability is enhanced by way of a protection path, over which data can be carried from the starting point to the destination point upon a detected failure along the working path. Upstream messages inform one or more MPLS switching systems to make a switchover from a working path to a protection path.

Abstract: Recovery time upon the failure of a link or switching system in an asynchronous data network can be minimized if downstream data switches provide upstream messages indicating to upstream switching system that the downstream traffic arrived in tact and was properly handled. Upon this loss or failure of the upstream status message to an upstream switching system, an upstream switching system can reroute data traffic around a failed link or failed switch with a minimal amount of lost data. The upstream status message is conveyed from a downstream switching system to an upstream switching system via a reverse notification tree data pathway.

Abstract: Recovery time upon the failure of a link or switching system in an asynchronous data network can be minimized if downstream data switches provide upstream messages indicating to upstream switching system that the downstream traffic arrived in tact and was properly handled. Upon this loss or failure of the upstream status message to an upstream switching system, an upstream switching system can reroute data traffic around a failed link or failed switch with a minimal amount of lost data. The upstream status message is conveyed from a downstream switching system to an upstream switching system via a reverse notification tree data pathway. The reverse notification pathway is established by using a messaging protocol between network switches by which the working and protection paths, among other things, are established.

Abstract: In a multi-protocol label system (MPLS) carrying data, a working path carries data from a starting point or node to a destination point or node via a working path. The working path includes the switches and physical media linking starting point and the destination point. MPLS system reliability is enhanced by way of a protection path, over which data can be carried from the starting point to the destination point upon a detected failure along the working path. Upstream messages inform one or more MPLS switching systems to make a switchover from a working path to a protection path.

Abstract: Recovery time upon the failure of a link or switching system in an asynchronous data network can be minimized if downstream data switches provide upstream messages indicating to upstream switching system that the downstream traffic arrived in tact and was properly handled. Upon this loss or failure of the upstream status message to an upstream switching system, an upstream switching system can reroute data traffic around a failed link or failed switch with a minimal amount of lost data. The upstream status message is conveyed from a downstream switching system to an upstream switching system via a reverse notification tree data pathway. The reverse notification pathway is established by using a messaging protocol between network switches by which the working and protection paths, among other things, are established.

Abstract: Recovery time upon the failure of a link or switching system in an asynchronous data network can be minimized if downstream data switches provide upstream messages indicating to upstream switching system that the downstream traffic arrived in tact and was properly handled. Upon this loss or failure of the upstream status message to an upstream switching system, an upstream switching system can reroute data traffic around a failed link or failed switch with a minimal amount of lost data. The upstream status message is conveyed from a downstream switching system to an upstream switching system via a reverse notification tree data pathway.

Abstract: A communication system (10) employs switching circuits, such as an add/drop multiplexer (70) and another add/drop multiplexer (110). The bandwidth of a circuit switched connection between the switching circuits is altered without taking down the connection.

Abstract: Recovery time upon the failure of a link or switching system in an asynchronous data network can be minimized if downstream data switches can provide upstream messages to upstream switching systems indicating to upstream switching systems that the downstream traffic arrived in tact and was properly handled. In one embodiment, the loss or failure of the upstream status message to an upstream switching system, causes an upstream switching system to reroute data traffic around a failed link or failed switch with a minimal amount of lost data.

Abstract: Recovery time upon the failure of a link or switching system in an asynchronous data network can be minimized if downstream data switches provide upstream messages indicating to upstream switching system that the downstream traffic arrived in tact and was properly handled. Upon this loss or failure of the upstream status message to an upstream switching system, an upstream switching system can reroute data traffic around a failed link or failed switch with a minimal amount of lost data. The upstream status message is conveyed from a downstream switching system to an upstream switching system via a reverse notification tree data pathway.

Abstract: A method for validating a path through a switched optical network is disclosed. A bit error rate at the end of the path is determined. The path is validated if the bit error rate is within a predefined range.

Abstract: A method for validating a path through a switched optical network is disclosed. A bit error rate at the end of the path is determined. The path is validated if the bit error rate is within a predefined range.

Abstract: A communication system (10) employs switching circuits, such as an add/drop multiplexer (70) and another add/drop multiplexer (110). The bandwidth of a circuit switched connection between the switching circuits is altered without taking down the connection.

Abstract: An apparatus that retrieves data from a plurality of long-term memory devices and delivers the data to a packet network over a plurality of channels, wherein each of the channels has a specific bandwidth requirement. The apparatus comprises a storage device adaptor which is connected to the long-term storage devices (such as disk systems, CD ROM, etc.). The adaptor reads data responsive to a selected channel from a storage device to a location in a buffer memory. A network interface reads data from the location in the buffer memory, formats the data, and sends the data to the packet network. A controller selects the channel in such a way that all channels receive their required bandwidth. The controller includes a table having a plurality of entries, wherein each entry may contain a channel identification. All channels have at least one entry in the table, and channels that require more bandwidth have multiple entries in the table.