Abstract: A method for enabling enable use of multiple active paths for TDM traffic over a packet switched network, comprises: receiving at least two copies of a replicated packet including TDM information via at least two paths through the packet switched network, the at least two copies of the replicated packet including at least a first copy of the replicated packet received via a first of the at least two paths, and a second copy of the replicated packet received via a second of the at least two paths; selecting a copy of the replicated packet from among the at least two copies of the replicated packet; inputting the selected copy of the replicated packet to a jitter buffer; discarding unselected ones of the at least two copies of the replicated packet; and outputting the selected copy of the replicated packet from the jitter buffer to a TDM endpoint device.

Abstract: Various embodiments relate to a method and apparatus for guaranteeing symmetrical delay in both directions for a Time-Division Multiplexing Pseudowire (“TDM-PW”) service on a packet switching network (“PSN”), the method including the steps of using a transport method to specify a first path including a corresponding pair of unidirectional service tunnels for the TDM PW service between a master router and a slave router, detecting a failure on either of the corresponding pair of unidirectional service tunnels of the first path between the master router and the slave router, switching the master router and the slave router to a second path including a corresponding pair of unidirectional service tunnels, resetting a jitter buffer on the master router and the slave router and adjusting the jitter buffer to a halfway point, and transmitting and receiving data using the second path including the corresponding pair of unidirectional service tunnels.

Abstract: Various embodiments relate to a method and apparatus for guaranteeing symmetrical delay in both directions for a Time-Division Multiplexing Pseudowire (“TDM-PW”) service on a packet switching network (“PSN”), the method including the steps of using a transport method to specify a first path including a corresponding pair of unidirectional service tunnels for the TDM PW service between a master router and a slave router, detecting a failure on either of the corresponding pair of unidirectional service tunnels of the first path between the master router and the slave router, switching the master router and the slave router to a second path including a corresponding pair of unidirectional service tunnels, resetting a jitter buffer on the master router and the slave router and adjusting the jitter buffer to a halfway point, and transmitting and receiving data using the second path including the corresponding pair of unidirectional service tunnels.

Abstract: A method and system are provided for synchronizing local clocks more quickly in a telecommunication network using IEEE 1588. A network element that receives timing signals from one or more possible parent clocks considers a measure of the reliability of the timing signals contained in Announce messages from the parent clock or clocks. The clock uses this reliability information in selecting one of the possible parent clock or clocks to use as the actual parent clock. Once the selection is made, the clock adjusts the filtering characteristics applied to timing signals received from the selected parent clock. The adjustments reflect how confident the parent clock is as to how stable the timing information it provides has become. If the indication of reliability contained in Announce messages received from the parent clock indicates that the timing information is not very reliable, then a high filter bandwidth is used in filtering the timing signals.

Abstract: A method and system are provided for reducing bandwidth usage in TDM CES systems. When a transmitting router receives a signal indicating that the access circuit is other than “normal”, and that therefore any TDM data arriving over the access circuit is not valid, the router signals a receiving router at the far end of a TDM Pseudowire that no packets will be sent and does not send any packets. When the receiving router receives such a signal it starts generating its own packets for placing in its jitter buffer. In this way, the jitter buffer maintains its fill level even when no packets are being sent. When the transmitting router receives notification indicating that its access circuit has returned to normal the router signals the receiving router that status has returned to normal, and begins sending packets again.

Abstract: An intermediate clock, either a boundary or a transparent clock, may have to adjust its local clock to match that of a grandmaster clock. If such adjustment is frequent or large, then the intermediate clock may not have much confidence in the reliability of the timing information it passes to a downstream clock in an IEEE 1588 Announce message even if the quality of its local clock is high. The intermediate clock determines a measure of the reliability of its timing information. The intermediate clock inserts an indication of the reliability of the timing information in a transmitted IEEE 1588 Announce message. The intermediate clock may consider an indication of reliability found in an Announce message it receives when inserting an indication of the reliability of timing information into an Announce message which it transmits.

Abstract: A method and system are provided for synchronizing local clocks more quickly in a telecommunication network using IEEE 1588. A network element that receives timing signals from one or more possible parent clocks considers a measure of the reliability of the timing signals contained in Announce messages from the parent clock or clocks. The clock uses this reliability information in selecting one of the possible parent clock or clocks to use as the actual parent clock. Once the selection is made, the clock adjusts the filtering characteristics applied to timing signals received from the selected parent clock. The adjustments reflect how confident the parent clock is as to how stable the timing information it provides has become. If the indication of reliability contained in Announce messages received from the parent clock indicates that the timing information is not very reliable, then a high filter bandwidth is used in filtering the timing signals.

Abstract: A method and system are provided for reducing bandwidth usage in TDM CES systems conveying analog data, such as voice data. A transmitting router receiving TDM frames for packetization monitors the digitized analog data in the TDM frames. If the analog data has not changed beyond a configured threshold for a configured length of time, the transmitting router signals the receiving router at the far end of a TDM Pseudowire that no packets for the TDM Pseudowire will be sent. The transmitting router does not send any packets over the TDM Pseudowire, not even packets with empty payloads. The receiving router a receiving such a signal starts to generate its own packets for placing in its jitter buffer. Valid data already within the jitter buffer is played out to the access port, but once this runs out dummy packets placed in the jitter buffer by the receiving router are played out. In this way the jitter buffer maintains its fill level even when no packets are being sent across the TDM Pseudowire.

Abstract: A method and system are provided for synchronizing local clocks more quickly in a telecommunication network using IEEE 1588. A network element that receives timing signals from one or more possible parent clocks considers a measure of the reliability of the timing signals contained in Announce messages from the parent clock or clocks. The clock uses this reliability information in selecting one of the possible parent clock or clocks to use as the actual parent clock. Once the selection is made, the clock adjusts the filtering characteristics applied to timing signals received from the selected parent clock. The adjustments reflect how confident the parent clock is as to how stable the timing information, it provides has become. If the indication of reliability contained in Announce messages received from the parent clock indicates that the timing information is not very reliable, then a high filter bandwidth is used in filtering the timing signals.

Abstract: A method and system are provided for synchronizing local clocks more quickly in a telecommunication network using IEEE 1588. A network element that receives timing signals from one or more possible parent clocks considers a measure of the reliability of the timing signals contained in Announce messages from the parent clock or clocks. The clock uses this reliability information in selecting one of the possible parent clock or clocks to use as the actual parent clock. Once the selection is made, the clock adjusts the filtering characteristics applied to timing signals received from the selected parent clock. The adjustments reflect how confident the parent clock is as to how stable the timing information, it provides has become. If the indication of reliability contained in Announce messages received from the parent clock indicates that the timing information is not very reliable, then a high filter bandwidth is used in filtering the timing signals.

Abstract: A method and system are provided for improving maintenance of timing information when a node enters holdover due to a lost connection between a sub-network and a reference clock. Each node within the sub-network sends information concerning the drift of its local oscillator to a single node, and the single node uses this information to determine timing information for the entire sub-network. The single node may also use knowledge of the characteristics of the local oscillators. In this way, drift from the reference clock can be minimized without incurring significant added hardware costs.

Abstract: A method and system are provided for reducing bandwidth usage in TDM CES systems conveying analog data, such as voice data. A transmitting router receiving TDM frames for packetization monitors the digitized analog data in the TDM frames. If the analog data has not changed beyond a configured threshold for a configured length of time, the transmitting router signals the receiving router at the far end of a TDM Pseudowire that no packets for the TDM Pseudowire will be sent. The transmitting router does not send any packets over the TDM Pseudowire, not even packets with empty payloads. The receiving router a receiving such a signal starts to generate its own packets for placing in its jitter buffer. Valid data already within the jitter buffer is played out to the access port, but once this runs out dummy packets placed in the jitter buffer by the receiving router are played out. In this way the jitter buffer maintains its fill level even when no packets are being sent across the TDM Pseudowire.

Abstract: A method and system are provided for reducing bandwidth usage in TDM CES systems. When a transmitting router receives a signal that the status of the access circuit is other than “normal”, and that therefore any TDM data arriving over the access circuit is not valid, the transmitting router signals a receiving router at the far end of a TDM Pseudowire that no packets for the TDM Pseudowire will be sent, and does not send any packets over the TDM Pseudowire, not even packets with empty payloads. When the receiving router receives such a signal, it starts to generate its own packets for placing in its jitter buffer. Valid packets already within the jitter buffer are played out to the access port, but once this runs out dummy packets placed in the jitter buffer by the router are played out. In this way, the jitter buffer maintains its fill level even when no packets are being sent across the TDM Pseudowire.

Abstract: An intermediate clock, either a boundary clock or a transparent clock, may have to adjust its local clock to match that of a grandmaster clock. If such adjustment is frequent or large, then the intermediate clock may not have much confidence in the reliability of the timing information it passes to a downstream clock in an IEEE 1588 Announce message even if the quality of its local clock is high. The intermediate clock determines a measure of the reliability of its timing information. The intermediate clock inserts an indication of the reliability of the timing information in a transmitted IEEE 1588 Announce message. The intermediate clock may consider an indication of reliability found in an Announce message it receives when inserting an indication of the reliability of timing information into an Announce message which it transmits.

Abstract: A method and apparatus are provided which allow telecommunication equipment to adjust its power consumption. By replicating the functionality of a standard component for processing traffic on a general purpose CPU, traffic can be routed within the equipment to the general purpose CPU for processing instead of the component under certain conditions. If the maximum bandwidth supported by the functionality on the general purpose CPU is less than the maximum bandwidth supported by the component, then the component can be powered down during times of low traffic and the traffic routed to the general purpose CPU instead. Since the maximum bandwidth supported by the functionality on the general purpose CPU is less than the maximum bandwidth supported by the component, less power is necessary to operate the telecommunication equipment and hence cost is reduced.

Abstract: A method and system are provided for allowing time-alignment of teleprotection measurements of power signals. Teleprotection observations are communicated between teleprotection ends through a packet switched network. At each end of a teleprotection segment, a teleprotection device communicates with the network through a router providing CES and located at the edge of the network. Clocks within the two routers are synchronized using IEEE 1588v2 signals. Using this synchronization, accurate one-way latency of data through the network between the two routers in each direction can be determined. The router at the incoming end of the faster path delays playout of packets by the difference between the two one-way latencies, thereby ensuring time-alignment of observations as they are sent from the routers to the teleprotection devices.

Abstract: A method and system are provided for allowing time-alignment of teleprotection measurements of power signals. Teleprotection observations are communicated between teleprotection ends through a packet switched network. At each end of a teleprotection segment, a teleprotection device communicates with the network through a router providing CES and located at the edge of the network. Playout of the jitter buffers of the CES routers is initiated only if the PDV is acceptable such that confidence that the packets from each CES router to the associated teleprotection device are synchronized. The fill level of the jitter buffer is determined a number of times, and then the average of the determined fill levels is compared with an expected fill level. If the difference between the average of the determined fill levels and the expected fill level exceeds a threshold, then the TDM CES is restarted.

Abstract: A method and system are provided for improving maintenance of timing information when a node enters holdover due to a lost connection between a sub-network and a reference clock. Each node within the sub-network sends information concerning the drift of its local oscillator to a single node, and the single node uses this information to determine timing information for the entire sub-network. The single node may also use knowledge of the characteristics of the local oscillators. In this way, drift from the reference clock can be minimized without incurring significant added hardware costs.

Abstract: A method and system are provided for allowing time-alignment of teleprotection measurements of power signals. Teleprotection observations are communicated between teleprotection ends through a packet switched network. At each end of a teleprotection segment, a teleprotection device communicates with the network through a router providing CES and located at the edge of the network. Clocks within the two routers are synchronized using IEEE 1588v2 signals. Using this synchronization, accurate one-way latency of data through the network between the two routers in each direction can be determined. The router at the incoming end of the faster path delays playout of packets by the difference between the two one-way latencies, thereby ensuring time-alignment of observations as they are sent from the routers to the teleprotection devices.

Abstract: A method and system are provided for reducing power usage in a telecommunications network. Policies are applied during traffic management of packets, the policies taking into account the power cost of transmitting a packet onward, including over a network. Embodiments are provided in which such policies are used during classification, scheduling, and traffic shaping of packets.