Abstract: Non-intrusive performance monitoring of a DS0 channel between a customer premises interface and a D4 channel bank includes an augmentation of existing channel bank equipment and a digital services communication device terminating the DS0 link at the customer site. An auxiliary signalling and performance monitoring arrangement is remotely accessible by a non-resident control site, for example by way of an RS-232 port of a line interface unit of the channel bank, thereby enabling the control site to perform prescribed network supervisory tasks with respect to one or more selected DS0 links, including provisioning of their associated loop equipment and performance monitoring of each DS0 loop. Office channel unit data port and line interface components of the channel bank are modified to provide bidirectional signalling capability via the receive segment of the channel bank's internal communications link.

Abstract: To remotely interrogate a telecommunications services channel unit resident in any office along a tandem network communication link, a control link establishment code sequence comprised of one or more sets of predefined digital code bytes is transmitted from a test system controller. The format of the control link establishment sequence is such that as it is forwarded down the link, any tandem channel unit or units that are intermediate the test system controller and the destination channel unit will transition to a transparent state, so that only the destination channel unit will be able transition to an interrogation, response mode. During the command-response mode, channel units connected in tandem between the selected channel unit and the interrogating test system controller continue to assume a transparent state, so that command and response messages propagate unmodified through such intermediate channel units.

Abstract: Non-intrusive performance monitoring of a DS0 channel between a customer premises interface and a D4 channel bank includes an augmentation of existing channel bank equipment and a digital services communication device terminating the DS0 link at the customer site. An auxiliary signalling and performance monitoring arrangement is remotely accessible by a non-resident control site, thereby enabling the control site to perform prescribed network supervisory tasks with respect to one or more selected DS0 links. Office channel unit data port and line interface components of the channel bank are modified to provide bidirectional signalling capability via the receive segment of the channel bank's internal communications link.

Abstract: To remotely interrogate a telecommunications services channel unit resident in any office along a tandem network communication link, a control link establishment code sequence comprised of one or more sets of predefined digital code bytes is transmitted from a test system controller. The format of the control link establishment sequence is such that as it is forwarded down the link, any tandem channel unit or units that are intermediate the test system controller and the destination channel unit will transition to a transparent state, so that only the destination channel unit will be able transition to an interrogation, response mode. During the command-response mode, channel units connected in tandem between the selected channel unit and the interrogating test system controller continue to assume a transparent state, so that command and response messages propagate unmodified through such intermediate channel units.