Abstract: An integrated network element includes the functions of multiple Ring add-drop-multiplexers and a digital cross connect. A user may provision cross connections between input and output path-level units of bandwidth referred to herein as “logical tributaries.” Each port within the integrated network element may be combined with one or more other ports to form a user-provisioned association of optical interface ports that is used for line protection (or SDH multiplex section protection) in a particular type of network configuration, referred to as a “port protection group”. Each port within a port protection group may have a plurality of logical tributaries associated with it.

Abstract: An integrated network element includes the functions of multiple Ring add-drop-multiplexers and a digital cross connect. A user may provision cross connections between input and output path-level units of bandwidth referred to herein as “logical tributaries.” Each port within the integrated network element may be combined with one or more other ports to form a user-provisioned association of optical interface ports that is used for line protection (or SDH multiplex section protection) in a particular type of network configuration, referred to as a “port protection group”. Each port within a port protection group may have a plurality of logical tributaries associated with it.

Abstract: A network control and test system for application to data communications networks. In a first mode of operation, the system learns the network configuration automatically and builds a table describing the network configuration. In a second mode of operation, the system automatically monitors the status of the network and each of its component units, periodically polling the network for changes of status and updating the information in the network configuration table to reflect such changes. In a third mode of operation, selective sites in the network may be tested under control of the system at previously selected and entered times of day, at which times previously chosen tests are performed without the need for operator intervention. In a fourth mode, an operator can manually command the system to perform certain tests and control functions.

Abstract: A network control and test system for application to data communications networks. In a first mode of operation, the system learns the network configuration automatically and builds a table describing the network configuration. In a second mode of operation, the system automatically monitors the status of the network and each of its component units, periodically polling the network for changes of status and updating the information in the network configuration table to reflect such changes. In a third mode of operation, selective sites in the network may be tested under control of the system at previously selected and entered times of day, at which times previously chosen tests are performed without the need for operator intervention. In a fourth mode, an operator can manually command the system to perform certain tests and control functions.

Abstract: A device for measuring the power of analog signals on telephone lines in a data communications network. A selection circuit couples a selected analog signal from one of the telephone lines to a measuring circuit. A full-wave rectifier and a low pass filter process and convey the selected signal to a plurality of open-loop comparators. Each comparator produces a binary signal that indicates whether the selected signal is greater or less than a reference power that corresponds to a predetermined power level. Each comparator energizes an inverter and driver that in turn energizes a light-emitting diode thereby to indicate the line signal power visually. However, the drivers are interconnected so only one light-emitting diode is energized at any given time. A blanking circuit disables the light-emitting diodes when rapid signal level changes occur. A self-testing circuit includes a damped oscillator for testing all the circuitry in the measuring device.

Abstract: A testing facility for a data communications network including modulators and demodulators, or modems, at central sites, at intermediate, or hubbing, sites, and at remote sites. Hubbing site testing units connect to respective host modems at the intermediate sites. The central testing unit transmits control words containing line address, drop address, and command characters. A configuration control circuit in each hubbing site testing unit generates signals that designate the particular location of the testing unit at the hubbing site. A validation circuit in each testing unit enables the testing unit to respond to the command character if two valid control words are received in succession. Thereafter the testing unit transmits back to the central testing unit signals in response to the test defined by the command character.