Abstract: The principles of the invention allow a network device, such as a router, to maintain a high level of services during a failure without substantially utilizing redundant hardware components. During execution, the network device stores a subset of state information associated with applications executing on the network device. In the event of a failure, the network device reconstructs data structures associated with at least one of the applications based on the stored subset of state information. Next, the network device restarts at least one of the applications to resolve the failure. While restarting, the network device may continue to receive and forward information, such as packets, and, therefore, may continue to provide a high level of access to client devices previously connected to the network device.

Abstract: A network analysis device for a digital communication network includes a digitizer to digitize a waveform representing a signal to produce a plurality of digital samples indicative of the waveform. The signal is communicated on the network. The network analysis device also includes a processor operable to analyze the digital samples to identify signal events, determine analog characteristics of the signal events, and decode the signal events, which are digital communications between network devices, based on the data, to selectively predict a failure mode.

Abstract: A network diagnostic device is disclosed that digitally samples the voltages on the cabling of the network, but does so at a much higher rate and with greater resolution then is required to minimally detect digital transmissions on the cabling. This sampling provides information on the analog characteristics of digital, noise, and interference signals on the network. Thus, network problems can be precisely diagnosed. The device includes a fast digitizer with a long memory and a system processor that statistically analyzes the signal events captured by the digitizer. The invention is also capable of performing time domain reflectometry (TDR) analysis of a functioning network. This is accomplished by placing a TDR signal on the network surrounded by a transmission that the network devices will interpret as a broadcast diagnostic packet. This will cause the network nodes to ignore the transmission. The digitizer, however, is able to detect the networks response to the TDR signal.

Abstract: A network diagnostic device is disclosed that digitally samples the voltages on the cabling of the network, but does so at a much higher rate and with greater resolution then is required to minimally detect digital transmissions on the cabling. This sampling provides information on the analog characteristics of digital, noise, and interference signals on the network. Thus, network problems can be precisely diagnosed. The device includes a fast digitizer with a long memory and a system processor that statistically analyzes the signal events captured by the digitizer. The invention is also capable of performing time domain reflectometry (TDR) analysis of a functioning network. This is accomplished by placing a TDR signal on the network surrounded by a transmission that the network devices will interpret as a broadcast diagnostic packet. This will cause the network nodes to ignore the transmission. The digitizer, however, is able to detect the networks response to the TDR signal.

Abstract: A network diagnostic device is disclosed that digitally samples the voltages on the cabling of the network, but does so at a much higher rate and with greater resolution then is required to minimally detect digital transmissions on the cabling. This sampling provides information on the analog characteristics of digital, noise, and interference signals on the network. Thus, network problems can be precisely diagnosed. The device includes a fast digitizer with a long memory and a system processor that statistically analyzes the signal events captured by the digitizer. The invention is also capable of performing time domain reflectometry (TDR) analysis of a functioning network. This is accomplished by placing a TDR signal on the network surrounded by a transmission that the network devices will interpret as a broadcast diagnostic packet. This will cause the network nodes to ignore the transmission. The digitizer, however, is able to detect the networks response to the TDR signal.