Abstract: A method for synchronizing the frequency of a client clock with a server clock frequency, such synchronization being performed through timing packets transmitted by the server towards the client through a telecommunication network wherein the method includes the transmission, by the server, of groups of timing packets such that an emission timing packet period (?1), measured between successive timing packets of a same group, is smaller than an emission group period (?3), measured between first timing packets of successive groups. Emission timing packet period (?1) is such that transmission delays of timing packets within a same group are practically correlated, and emission group period (?3) is such that transmission delays of timing packets from different groups are practically uncorrelated.

Abstract: An exemplary technique is provided for synchronizing master and slave clocks of a packet-switched network. The network contains at least two equipments that are connected to one another via an aggregated connection made up of at least two links and that are located between the master and slave clocks to enable them to transmit synchronization packets to one another using a timestamp protocol. The technique includes (a) obtaining a distribution of the synchronization packets in at least one subset of the links that transport these synchronization packets, and (b) transmitting to the slave clock first information representative of that distribution, second information representative of timestamps associated with the synchronization packets, and third information representative of packet transmission times over the at least one subset of links, to synchronize the slave clock to the master clock as a function of at least the first, second, and third information transmitted.

Abstract: A method for synchronizing a plurality of clocks arranged within a plurality of nodes of a packet-switching network comprises comparing parameters that relate to the plurality of clocks in order to determine master-slave relationships between the plurality of clocks, and exchanging time-stamped messages over the packet-switching network each time between a master clock and an associated slave clock to make the associated slave clock subservient to the master clock. A node of the packet-switching network comprises a frequency source controlled by a synchronous physical layer technology. The parameters that relate to a clock of the node comprise a parameter that relates to the frequency source to determine the master slave relationships based on one property of the frequency source.

Abstract: A method for establishing a connection across resource domains comprises determining source and destination end-points for the connection; determining, by a service agent, a chain of adjacent service elements suitable for joining the source and destination end-points based on the identified edges; requesting, by the service agent, a first service provider associated to a service element in the chain to select a first connection segment embodying the service element; receiving, by the service agent, an inter-carrier communication resource identifier from the first service provider, the inter-carrier communication resource identifier indicating communication resources at an inter-carrier interface between an end point of the first connection segment and a resource domain associated to an adjacent service element in the chain; and transferring, by the service agent, the inter-carrier communication resource identifier to a second service provider associated to the adjacent service element.

Abstract: In a method for monitoring the residence time across nodes of a communication network including a transparent clock-based synchronization architecture, the method includes configuring and generating a tunable and traceable packet dedicated to delay measurements. The method further includes measuring the packet resident time across a network node by a transparent clock, storing, at the level of the network node, the measured residence time, and retrieving the stored residence time by a Network protocol.

Abstract: A method for measuring the resident time of a probe message in at least a network node within a network path, includes registering the receive timestamp of the probe message, writing the receive timestamp into a dedicated field within the received probe message, and checking the Time-To-Live value of the probe message. If the Time-To-Live value is not null, the Time-To-Live value is decremented by one. If the Time-To-Live value is equal to one, then the method includes registering the transmit timestamp of the probe message, computing the probe message resident time within the network node by subtracting the registered receive timestamp from the registered transmit timestamp, writting the computed resident time into a field within the probe message, and changing the value of a flag within the received probe message in order to protect the resident time from being over written by subsequent action on the probe message.

Abstract: A method for handling at least one encapsulated synchronization message by a tunnel node including a transparent clock, includes generating a signature from the encapsulated synchronization message and generating, or updating if it has already been generated, a tunnel follow-up message. The tunnel follow-up message includes the encapsulated synchronization message signature. The method further includes measuring the encapsulated synchronization message residence time across the tunnel node, and updating the correction field of the tunnel follow-up message with the measured residence time.

Abstract: The invention is directed to a clock module and method for distributing a time reference to at least one clock in a packet-switched network. The clock module includes a slave port, a master port and a local clock. The method comprises the steps of receiving a first synchronization packet at the slave port, the first synchronization packet comprising a first master clock timestamp and generating at least one internal signal comprising the first master clock timestamp. The method also includes the steps of transmitting the at least one internal signal to the master port and receiving the at least one internal signal at the master port. Then a method includes determining the internal propagation time of the signal through the clock module and generating a second synchronization packet at the master port comprising a second master clock timestamp, the second master clock timestamp comprising the sum of the first master clock timestamp and the internal propagation time.

Abstract: A network element for a packet-switched network has a plurality of network ports for exchanging synchronization messages with further network elements, a local clock, a timestamp generation module associated to each network port for triggering generation of a timestamp, and a synchronization control module selectively configurable in a first operating mode and a second operating mode as a function of a configuration signal. When the synchronization control module is configured in the first operating mode, it is adapted to adjust an offset of the local clock as a function of the timestamps of the synchronization messages received through the slave port. When the synchronization control module is configured in the second operating mode, it is adapted to compute a residence time of a synchronization message in the network element as a function of the timestamps obtained at the time of receiving and sending the synchronization message.

Abstract: A method for automatic management of a timestamp-based synchronization protocol within a packet-based network to synchronize a slave within a synchronization topology including a plurality of masters, the slave clock being locked to a master clock at an initialization time, said method comprising an assessment step of end-to-end packet delay variation on the basis of the slave clock accuracy, over a plurality of (slave, path, master) combinations, each path linking the slave to a master.

Abstract: The embodiments of the present invention refer to an interworking agent aimed at being installed in a network node comprising a Precision Time Protocol “PTP” module, said agent comprising: a synchronization-side interface configured to measure Precision Time Protocol “PTP” metrics for detecting a Precision Time Protocol “PTP” signal failure, read and modify Precision Time Protocol “PTP” parameters of the Precision Time Protocol “PTP” module, at least one network-side interface configured to measure network metrics for selecting the optimal path for packet synchronization signals monitor network events for detecting a network path change, read and modify signals exchanged with a network planning entity and, signals exchanged between network nodes at the network level in order to communicate with remote interworking agents located in other network nodes.

Abstract: A method is dedicated to synchronizing master (HM) and slave clocks (HE) of a packet-switched network comprising at least two equipments (E1, E2) that are connected to one another via an aggregated connection made up of at least two links (L1-L3) and that are located between said master (HM) and slave clocks (HE) in order to enable them to transmit synchronization packets to one another using a timestamp protocol.

Abstract: A method is devoted to the synchronization of master (HM) and slave (HE) clocks of a packet-switched network, capable of exchanging synchronization packet flows via intermediary equipment (E1-E9) of that network, connected to one another. This method comprises the following steps: i) determining within each piece of intermediary equipment (E1-E9) the instant transit times of packets belonging to a first group of packets of at least one chosen flow of synchronization packets, then acting on packets from a second group of packets of that chosen flow so that their instant transit times within each piece of intermediary equipment (E1-E9) are each roughly equal to a corresponding maximum transit time, and ii) filtering the packets of the chosen flow at least within the slave clock (HE) in order to synchronize it to the master clock (HM) by means of the processed packets of that chosen flow's second group.

Abstract: Exemplary methods and apparatuses are provided for a method for correcting for a delay asymmetry of synchronization messages transmitted within a packet-switched network between a master clock and a slave clock, in which the delay asymmetry of the path connecting the master clock to the slave clock is determined and corrected locally within at least one link of said path. One or more signals are transmitted on one or more wavelengths over at least one optical fiber. The one or more signals are received and detected on the one or more wavelengths over the at least one optical fiber. The technique determines an arrival time difference between the received and detected one or more signals, and calculates a delay asymmetry of an adjacent link based on the time difference.

Abstract: The embodiments of the present invention pertaining to a method for distributing time between a first and a second Synchronous Ethernet “SyncE” domain, said first and second domains being interconnected by a third, Synchronous Optical Networking/Synchronous Digital Hierarchy “SDH-SONET” domain in which a time-associated reference parameter is distributed, through Synchronous Ethernet “SyncE” domains, by means of at least one additional Type Length Value “TLV” field of an Ethernet Synchronization Messaging Channel “ESMC” message and a corresponding time-associated reference parameter is distributed, through the Synchronous Optical Networking/Synchronous Digital Hierarchy “SONET-SDH” domain by means of at least one additional Type Length Value “TLV” field within a message of the IEEE 1588 V2 protocol.

Abstract: The embodiments of the present invention describe a method for transmitting an Ethernet Synchronization Messaging Channel “ESMC” message between a first and a second Synchronous Ethernet “SyncE” domain, said first and second domains being interconnected by a third, Synchronous Optical Networking/Synchronous Digital Hierarchy “SONET/SDH” domain, in which at least one part of said Ethernet Synchronization Messaging Channel “ESMC” message is encapsulated when entering said third domain and unencapsulated when exiting said third domain, so as to create a network tunnel through the Synchronous Optical Networking/Synchronous Digital Hierarchy “SONET/SDH” domain.

Abstract: The method for detecting and managing a synchronization failure of a transparent clock is used in a packet network in order to determine and correct residence time of time-stamped packets within a traversed element of said network. The transparent clock is part of a Master/Slave synchronization path including a plurality of network elements and their associated transparent clocks. The method includes transmitting time-stamped packets from the Master to the Slave through different synchronization paths in order to have the Slave receiving multiple time signals transmitted through different paths, and determining a failure within a transparent clock of a failed/failing synchronization path if the time signal provided by said failed/failing path differs from the time signal provided by the other transmitting path(s).

Abstract: A method for synchronizing the frequency of a client clock with a server clock frequency, such synchronization being performed through timing packets transmitted by the server towards the client through a telecommunication network wherein the method includes the transmission, by the server, of groups of timing packets such that an emission timing packet period (?1), measured between successive timing packets of a same group, is smaller than an emission group period (?3), measured between first timing packets of successive groups. Emission timing packet period (?1) is such that transmission delays of timing packets within a same group are practically correlated, and emission group period (?3) is such that transmission delays of timing packets from different groups are practically uncorrelated.

Abstract: A method for establishing a connection across resource domains comprises: determining source and destination end-points for the connection, determining, by a service agent, a chain of adjacent service elements suitable for joining the source and destination end-points based on the identified edges, requesting, by the service agent, a first service provider (35) associated to a service element in the chain to select a first connection segment embodying the service element, receiving, by the service agent, an inter-carrier communication resource identifier from the first service provider, said inter-carrier communication resource identifier indicating communication resources at an inter-carrier interface between an end point of the first connection segment and a resource domain associated to an adjacent service element in the chain, transferring, by the service agent, the inter-carrier communication resource identifier to a second service provider (25) associated to the adjacent service element.

Abstract: A method for synchronising a plurality of clocks (1, 5, 6, 7, 8) arranged within a plurality of nodes (11, 15, 16, 17, 18) of a packet-switching network comprising the steps consisting in comparing parameters relating to the clocks in order to determine master-slave relationships between said clocks, and to exchange time-stamped messages over the packet-switching network each time between a master clock (5) and an associated slave clock (6) in order to make the slave clock subservient to the master clock. A node (15) of said network comprises a frequency source controlled by a synchronous physical layer technology. The parameters relating to a clock (5) of said node comprise a parameter relating to said frequency source, so as to determine said master-slave relationships based on one property of said frequency source controlled by a synchronous physical layer technology.