Agilent Technologies, Inc.

Jds Uniphase Corporation

Other

Martin Curran-Gray

Slawomir K Ilnicki

Andrew Robert Lehane

Takashi Hidai

Jefferson B Burch

Lance A Tatman

Valery Kanevsky

Demessie Girma

Colin Arthur

Slawomir K Iinickl

Slawomir K Ilnickl

Arbitrary numerical distributions are presented for use in devices having limited processing and storage capabilities by having the device accept strings of arbitrarily distributed numbers from a source outside of the device. In one embodiment, a master controller creates a table of values which follow the desired minimum, maximum, mean, and standard deviation, etc. of the particular desired statistical distribution required. The created table is then communicated to the limited capacity device and can be used whenever a distribution of random values is required. The master controller could have one of several slave devices associated with it in the system. In another embodiment, where the storage capability of the device is large enough to store a table of values with sufficient different entries to create a distribution of satisfactory 'randomness' for the particular application, a random number generator within the device is used to select the order of presentation of the table of values.

Systems and methods for producing pseudo-random number distributions in devices having limited processing and storage capabilities

An in-band inspection device receives a packet and/or frame, and inspects the packet and/or frame 'on the fly.' The device can accept, reject, and/or modify the received packet and/or frame in accordance with the inspection. The device can operate in a fast mode wherein the received packet and/or frame can be transmitted as soon as, for example, a port address in the packet and/or frame is received, or in a slow mode wherein the received packet frame is buffered until, for example, at least the CRC of the packet and/or frame is beginning to be received.

Inspection of data

A network element is provided with the capability to perform monitoring and/or measurement functions on the element and the network of which it is a part. The monitoring/measurement functionality is implemented by programmable devices to enable the functionality to be modified and updated without removing the network element from service.

Communications network elements and methods of monitoring communications networks

A communications apparatus includes an input for receiving a data stream being transmitted from a first network node to a second network node using a main channel. A processing resource of the communications apparatus identifies data signifying an idle period within the data stream and determines whether the idle period is at least a suitable minimum duration to support initiating transmission of sub-channel data in place of at least part of the data signifying the idle period. Further, the processing resource is arranged to identify when the idle period is not of the suitable minimum duration and a need arises to transmit the sub-channel data within a predetermined period of time. In such circumstances, the processing resource sends a flow control message upstream to the first network node to halt transmissions therefrom, thereby generating the idle period of at least the suitable minimum duration.

Communications system, apparatus for creating a sub-channel and method therefor

A method for real time monitoring of at least one TCP flow involves monitoring TCP packets flowing past a particular point in a TCP network. A flow trace including at least source and destination addresses for each TCP packet is determined and a packet record for each monitored TCP packet within a determined flow trace is created. Each of the packet records includes at least a transmitted order number and an actual received sequence number, from which an expected received sequence number for each packet record is determined and stored in the packet record. The difference between the expected received sequence number for each packet record and the expected received sequence number for the previous packet record is used to thereby determine by how much a particular packet was moved out of sequence.

Real time monitoring of TCP flows

A communications apparatus is capable of being disposed in-line in a communications link that supports a main communications channel. The communications link connects a first host to a second host. The communications apparatus comprises an application logic that supports a sub-channel within the main channel. When the main channel is potentially faulty, the application logic is arranged to monitor the main channel to determine an error condition and send a message by replacing data reserved for control purposes in order to communicate the error condition as sub-channel data.

Communications apparatus, system and method of creating a sub-channel

An in-line network simulator is provided that disrupts packets traveling through it to simulate network conditions. According to one embodiment, a method comprises receiving, at an in-line network simulator, packets sent from a source node to a destination node. The in-line network simulator classifies the received packets into respective ones of a plurality of different classifications, and disrupts the received packets based on corresponding disruption characteristics defined for their respective classifications. Such disrupting of the packets may include selectively performing at least one of delaying, dropping, and reordering of the received packets.

In-line network simulator

Aspects of the disclosure embody a multi-master two-wire serial bus that comprises two or more chained two-wire serial busses. The chained two-wire serial busses include a host two-wire serial bus with a first master device and one or more slave devices. One or more chained two-wire serial busses are coupled to the host bus wherein one or more slave devices on the host two-wire serial bus operate as second master devices, which comprise a digital state machine including a two-wire serial slave component coupled to the master device and a two-wire serial master component coupled to the slave devices on the chained two-wire serial bus. The digital state machine emulates a slave device on the host two-wire serial bus and a master device on the chained two-wire serial bus.

Multi-master, chained two-wire serial bus

By equipping receiving devices in a network with synchronizable clocks it is possible to periodically send an 'impulse' signal that is received by all of the clocks at the same (or relatively the same) instant of time. The accuracy of the impulse clock need not be high, only that its signal reach all the clocks approximately at the same time. In one embodiment, a transmitting device, upon receipt of the synchronizing impulse signal, sends a packet of data bearing the sending device's epoch time-stamp to a receiving device. The data packet makes its way through the network element to the receiving device and the time-stamp is used by the receiving device to calculate the difference between the epoch time of the receiver and the epoch time of the sender. Effectively, this procedure removes the unknown network element transit times from the equation and allows the devices to operate in a synchronized manner.

Growing community of inventors

Fife, United Kingdom

Martin Curran-Gray