Abstract: According to one embodiment, maintenance points of a maintenance entity group are identified. The maintenance points comprise end points and intermediate points. A secure connectivity association set is established for the maintenance points. The following is performed for each frame of a number of frames: determining security data of the secure connectivity association set; placing the security data into a frame; and communicating the frame to a maintenance point. The maintenance point is configured to determine whether a frame is acceptable from the security data of the frame.

Abstract: According to one embodiment, maintenance points of a maintenance entity group are identified. The maintenance points comprise end points and intermediate points. A secure connectivity association set is established for the maintenance points. The following is performed for each frame of a number of frames: determining security data of the secure connectivity association set; placing the security data into a frame; and communicating the frame to a maintenance point. The maintenance point is configured to determine whether a frame is acceptable from the security data of the frame.

Abstract: A method for changing the data transmission rates in a synchronous data communication system including a first modem and a second modem coupled together through a transmission channel, the transmission channel including a first path for transmissions from the first modem to the second modem and a second path for transmission from the second modem to the first modem, includes the steps of determining, at the first modem, that the second path of the transmission channel is adequately high in quality to support an increase in transmission rate. Next it is determined, at the second modem, that the first path of the transmission channel is adequately high in quality to support an increase in transmission rate. A training sequence is then transmitted at an increased transmission rate from the second modem to the first modem. Next, a training sequence is transmitted at the increased transmission rate from the first modem to the second modem.

Abstract: A system for diagnosing and controlling operation of a plurality of modems, some located at a central site and others at various remote sites. A processor located at the central site selectively addresses microprocessor test and control units at each modem over a secondary channel. The microprocessor test and control units respond to commands to configure and perform various modem tests, operate autonomously to monitor various alarm conditions, and format status reports and alarm maydays for transmission back to the central processor. The system is capable of performing a wide variety of testing, monitoring and network control functions for a very large network of modems.