Alcatel Lucent

Nokia Solutions and Networks Oy

Kin Yee Wong

Peter Roberts

Ian Leighton

Chad V Mccarthy

Wayne Groff

David George McKay

Chad Mccarthy

Andre Poulin

Joseph Graham Rorai

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.

Active-active TDM PW with asymmetry control

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.

Minimizing network bandwidth for TDM CES

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. The transmitting router continues to monitor the received digitized analog data, and only when it determines that the analog data has changed beyond the threshold does the transmitting router signal the receiving router, and begins sending packets once again. The method and system thereby reduce the bandwidth usage in TDM CES systems conveying analog data by refraining from needlessly sending packets over the TDM-Pseudowire when the analog data is not changing.

Minimizing network bandwidth for voice services over TDM CES

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.

Using multiple oscillators across a sub-network for improved holdover

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.

Symmetrical latency with TDM circuit emulated service

The invention is directed to providing a system and method for monitoring a clock synchronization metric in a timing-over-packet system to provide a metric for service-level agreements (SLA), by providing a measure of the stability of the packet transfer delay relative to a representative statistic such as a median or minimum.

Network impairment metrics for timing over packet

The invention is directed to a method and system for providing synchronization clock performance simulation in a timing-over-packet network having a network management system. The system retrieves information from nodes in a network and determines a timing-over-packet topology in a simulated model of the network, and determines clock stability statistics. The system further accepts simulation inputs such as addition or deletion of nodes in the simulated network, or introduction of failures into in the simulated network. The system provides predicted clock stability performance of an existing network under various simulated conditions without requiring modifications or introduction of failures to the existing network which would be useful for network optimization and network planning.

Network sync planning and failure simulations

The invention is directed to providing a method and system for monitoring and managing from a network management entity, timing-over-packet synchronization performance in a packet switching network having multiple network nodes. The network management entity determines a physical topology and a synchronization topology of the network and monitors synchronization performance by collecting virtual path information.

Network timing topology via network manager

Various exemplary embodiments include a method and related system and monitoring entity including one or more of the following: generating timing information at a master node in a packet-switched network, the timing information specifying a value of a master clock; communicating the timing information from the master node to a plurality of slave nodes over a first plurality of time-division multiplexing (TDM) pseudowires; running a digital phase-locked loop on each slave node to synchronize each slave node to the master clock, wherein each digital phase-locked loop outputs a frequency at which the respective slave node is operating; sending the frequency outputted by each digital phase-locked loop to a monitoring entity over a second plurality of TDM pseudowires; utilizing the outputted frequencies at the monitoring entity to identify all slave nodes that are experiencing timing problems; and implementing a remedial measure for all slave nodes that are experiencing timing problems.

Network element clocking accuracy and stability monitoring over a packet-switched network

A system and method are provided for enabling additional capacity or features on telecommunication nodes without requiring replacement of hardware. Service providers purchase hardware which is fully capable of providing a full suite of features and providing a large bandwidth capacity. However, depending on the amount of payment by the service provider, not all of the features or the bandwidth capacity is enabled. If the service provider wishes to increase the number of features or the capacity of a node, the additional features or capacity are enabled using software after payment to the vendor. This allows service providers to enter the market at an initially relatively low expense. Additional features and capacity can be purchased and enabled using software as demand grows, without having to purchase replacement hardware.

Growing community of inventors

Ottawa, Canada

Kin Yee Wong