Abstract: Component malfunctions in passive optical networks (PON) can increase bit error rates and decrease signal-to-noise ratio of communications signals. These faults may cause the receivers of the signals, either the optical line terminal (OLT) or optical network terminals (ONTs), to experience intermittent faults and/or may result in misinterpreted commands that disrupt other ONT's communication, resulting in a rogue ONT condition. Existing PON protocol detection methods may not detect these types of malfunctions. An embodiment of the present invention identifies faults in a PON by transmitting a test series of data patterns via an optical communications path from a first optical network node to a second optical network node. The test series is compared to an expected series of data patterns. An error rate may be calculated as a function of the differences between the test series and expected series. The error rate may be reported to identify faults in the PON.

Abstract: Component malfunctions in passive optical networks (PON) can increase bit error rates and decrease signal-to-noise ratio of communications signals. These faults may cause the receivers of the signals, either the optical line terminal (OLT) or optical network terminals (ONTs), to experience intermittent faults and/or may result in misinterpreted commands that disrupt other ONT's communication, resulting in a rogue ONT condition. Existing PON protocol detection methods may not detect these types of malfunctions. An embodiment of the present invention identifies faults in a PON by transmitting a test series of data patterns via an optical communications path from a first optical network node to a second optical network node. The test series is compared to an expected series of data patterns. An error rate may be calculated as a function of the differences between the test series and expected series. The error rate may be reported to identify faults in the PON.

Abstract: Jitter in a clock signal can cause communications faults in communications networks, such as in networks in which downstream nodes use recovered clock signals as timing for upstream communications. An embodiment of the present invention detects and compensates for jitter in a network by recovering a reference clock associated with communications signals between nodes, such as an Optical Line Terminal (OLT) and Optical Network Terminal (ONT) in a Passive Optical Network (PON). A local clock is synchronized with the reference clock. Jitter induced faults may be detected and compensated for by increasing the synchronization rate, then decreasing the synchronization rate until jitter induced faults begin to occur. A loss or change in a rate of communications errors occurring as a function of the synchronization rate may be monitored and reported to a system operator. Compensating for jitter by adjusting the synchronization rate provides for robust communications between network nodes.

Abstract: Malfunctions in a communications network may introduce an unacceptably low level of reliability for many users, thereby slowing further adoption of Internet Protocol (IP) telephony, for example. In an example embodiment of the present invention, a method and corresponding apparatus for supporting a call in a presence of a fault in a network is provided. The method includes supporting a primary protocol to service a call between near-end and far-end access nodes associated with two or more callers. Signaling information in the primary protocol supporting the call may be identified and used to establish a backup protocol between the near-end and far-end access nodes. The primary protocol may be monitored for a fault and, in an event a fault occurs, supporting the call using the backup protocol. As a result, IP telephony may be transported in a more reliable manner, thereby reducing the number of dropped and uncompleted calls.

Abstract: An apparatus and a method for verifying optical system performance using a signaling value test are disclosed. After instructing the first optical interface device and the second optical interface device to enter a verification mode, the first optical interface device sends first verification data to the second optical interface device via an optical communications network. In one embodiment, the first optical interface device is an optical line termination (“OLT”) and the second optical interface device is an optical network terminal (“ONT”). Upon composing the first reply message in response to content received by the second optical interface in accordance with the first verification data, the second optical interface device forwards the first reply message to the first optical interface device.

Abstract: An apparatus and a method of enhancing data integrity for data transmission over an optical network are disclosed. Upon detecting a low performance condition associated to the optical communications network, an error correcting code (“ECC”) device is activated. The ECC device inserts the ECC to a data stream to form an ECC data stream. Once the ECC data stream reaches to the destination, the ECC device corrects any errors incurred during the transmission, and removes the ECC from the ECC data stream. It should be noted that the ECC device can also be activated by a request from a network operator.

Abstract: Jitter in a clock signal can cause communications faults in communications networks, such as in networks in which downstream nodes use recovered clock signals as timing for upstream communications. An embodiment of the present invention detects and compensates for jitter in a network by recovering a reference clock associated with communications signals between nodes, such as an Optical Line Terminal (OLT) and Optical Network Terminal (ONT) in a Passive Optical Network (PON). A local clock is synchronized with the reference clock. Jitter induced faults may be detected and compensated for by increasing the synchronization rate, then decreasing the synchronization rate until jitter induced faults begin to occur. A loss or change in a rate of communications errors occurring as a function of the synchronization rate may be monitored and reported to a system operator. Compensating for jitter by adjusting the synchronization rate provides for robust communications between network nodes.