Disclosed herein are switch devices in terminal ends of a network and methods of using same. One embodiment relates to a terminal end of a network including a terminal end transceiver configured to communicate with one or more end user devices, and a switch device configured to automatically route communication at the terminal end transceiver between a primary communication path with a central office and an auxiliary communication path with the central office. Another embodiment relates to a method of switching between primary and auxiliary communication paths at a terminal end. Automatic switching is particularly applicable in a looped communication architecture with redundant communication paths for preventing interruption and increasing reliability for an improved user experience. Another embodiment relates to indexing with splices to reduce connections in a communication path and increase signal quality.

In an optical network having a terrestrial terminal and an open cable interface (OCI) connecting a submarine cable to a terrestrial cable, the OCI may include a filter positioned on an optical path between the terrestrial cable and the submarine cable and configured to pass first communication signals of a first frequency band, and filter out secondary signals of a second frequency band that does not overlap with the first frequency band. The secondary signals may be looped back to the terrestrial terminal. The terrestrial terminal may detect the looped back secondary signals, and in response, determine the presence of the OCI and that the supervisory signals were rerouted by the OCI.

In an optical network having a terrestrial terminal and an open cable interface (OCI) connecting a submarine cable to a terrestrial cable, the OCI may include a filter positioned on an optical path between the terrestrial cable and the submarine cable and configured to pass first communication signals of a first frequency band, and filter out secondary signals of a second frequency band that does not overlap with the first frequency band. The secondary signals may be looped back to the terrestrial terminal. The terrestrial terminal may detect the looped back secondary signals, and in response, determine the presence of the OCI and that the supervisory signals were rerouted by the OCI.

Systems, methods, and storage media for detecting a security intrusion of a network device are disclosed. Exemplary implementations may include a method involving, in the network device including a processor, monitor a light signal associated with a security enabled port of the network device; and in response to detecting a change in the light signal, initiate a security alert.

Systems, methods, and storage media for detecting a security intrusion of a network device are disclosed. Exemplary implementations may include a method involving, in the network device including a processor, monitor a light signal associated with a security enabled port of the network device; and in response to detecting a change in the light signal, initiate a security alert.

In an optical network having a terrestrial terminal and an open cable interface (OCI) connecting a submarine cable to a terrestrial cable, the OCI may include a filter positioned on an optical path between the terrestrial cable and the submarine cable and configured to pass first communication signals of a first frequency band, and filter out secondary signals of a second frequency band that does not overlap with the first frequency band. The secondary signals may be looped back to the terrestrial terminal. The terrestrial terminal may detect the looped back secondary signals, and in response, determine the presence of the OCI and that the supervisory signals were rerouted by the OCI.

In an optical network having a terrestrial terminal and an open cable interface (OCI) connecting a submarine cable to a terrestrial cable, the OCI may include a filter positioned on an optical path between the terrestrial cable and the submarine cable and configured to pass first communication signals of a first frequency band, and filter out secondary signals of a second frequency band that does not overlap with the first frequency band. The secondary signals may be looped back to the terrestrial terminal. The terrestrial terminal may detect the looped back secondary signals, and in response, determine the presence of the OCI and that the supervisory signals were rerouted by the OCI.

In some implementations, a device may transmit communication data to a transceiver via an access fiber optic cable. The device may determine that fiber sensing is to be performed for the access fiber optic cable. The device may cease transmission of the communication data for a predetermined time period. The device may generate an optical pulse after ceasing transmission of the communication data. The device may transmit the optical pulse to the transceiver via the access fiber optic cable. The device may receive, prior to expiration of the predetermined time period, a reflected signal from the access fiber optic cable based on the optical pulse. The device may analyze the reflected signal to generate sensing results. The device may perform one or more actions based on the sensing results.

In some implementations, a device may transmit communication data to a transceiver via an access fiber optic cable. The device may determine that fiber sensing is to be performed for the access fiber optic cable. The device may cease transmission of the communication data for a predetermined time period. The device may generate an optical pulse after ceasing transmission of the communication data. The device may transmit the optical pulse to the transceiver via the access fiber optic cable. The device may receive, prior to expiration of the predetermined time period, a reflected signal from the access fiber optic cable based on the optical pulse. The device may analyze the reflected signal to generate sensing results. The device may perform one or more actions based on the sensing results.

The present invention enables shortening the time required for resuming communication in a protection method that uses a backup path in an optical communication system that includes a master station device and multiple slave station devices. The slave station devices are connected to a loop path in parallel. The communication paths between the master station device and the slave station devices include a normal path and a backup path. The master station device executes communication control processing with respect to the slave station devices based on the RTTs. A first slave station device is one of the slave station devices, and a second slave station device is a slave station device that cannot perform communication via the normal path. If a second slave station device is detected, the master station device calculates a second backup path RTT for the second slave station device based on the first normal path RTT and the first backup path RTT for the first slave station device and a second normal path RTT for the second slave station device. The master station device then resumes communication control processing for the second slave station device based on the calculated second backup path RTT.