Abstract: Digital communications receive signals from the network tap represent “tapped” data. The tapped data is forwarded to a time stamp module. The time stamp module generates a time stamp and inserts the time stamp in each packet body. The time stamp represents a “time” when data packet content is considered to be generated at a sending node from which the tapped data originates. A packet time-stamped in this manner is then forwarded to one or more receivers, such as the recorder for additional processing. One such processing may be a performance measurement based at least in part on the time stamp that, as described, represents the time at which data packet content is considered to have been generated by the sending node. The network tap may be filterable, and either copper-based or a fiber tap.

Abstract: Digital communications receive signals from the network tap represent “tapped” data. The tapped data is forwarded to a time stamp module. The time stamp module generates a time stamp and inserts the time stamp in each packet body. The time stamp represents a “time” when data packet content is considered to be generated at a sending node from which the tapped data originates. A packet time-stamped in this manner is then forwarded to one or more receivers, such as the recorder for additional processing. One such processing may be a performance measurement based at least in part on the time stamp that, as described, represents the time at which data packet content is considered to have been generated by the sending node. The network tap may be filterable, and either copper-based or a fiber tap.

Abstract: The present invention relates to a method for identifying inaccurate time measurements in a local area network. The local area network comprises a sending device (2), such as a time client, a destination device (3), such as a timeserver, and a switching device and/or a store-and-forward device (6). A time request packet (4) is rejected if it arrives at the time client or timeserver within a given or calculated minimum distance from the preceding network packet. The time request packet (4) is also rejected if it falls outside a set of calculated error limits based on a set of estimates. Those estimates are kept in the time client memory and updated according to a given set of rules.

Abstract: It is described a method on a network element with one or more communication ports for transmitting and receiving data packets to and from other network elements in a network for the purpose of synchronization of clocks in a network, said network element comprising a time synchronization module, a time synchronization module clock and a database.

Abstract: The invention relates to a method for controlling a network element with a plurality of communication ports for transmitting and receiving data packets to and from other network elements in a network, wherein a spanning tree topology model of at least a subset of the network is stored in at least one database in the network element. The method comprises the steps of:—detecting an event indicating a change in the topology of the network; updating the spanning tree topology model of the subset of the network based on information derived from the topology change event, said subset including the network element, the origin of the topology change event and the network elements that are affected by the topology change, and—determining if the network element is operating as a topology handler for the detected event.

Abstract: The present invention relates to a method for identifying inaccurate time measurements in a local area network. The local area network comprises a sending device (2), such as a time client, a destination device (3), such as a timeserver, and a switching device and/or a store-and-forward device (6). A time request packet (4) is rejected if it arrives at the time client or timeserver within a given or calculated minimum distance from the preceding network packet. The time request packet (4) is also rejected if it falls outside a set of calculated error limits based on a set of estimates. Those estimates are kept in the time client memory and updated according to a given set of rules.

Abstract: The present invention relates to a method for ensuring access to a transmission medium at a predetermined point in time, for transmission of a data packet. This is achieved by making one or more communication pons on which the packet is to be transmitted unavailable for conflicting traffic for a period of time that is set to expire at the desired point in time, and preparing the data packet to be transmitted as soon as said communication port again is made available. Also described is a time server for distributing time information packets utilizing the method.