Jds Uniphase Corporation

Agilent Technologies, Inc.

Slawomir K Ilnicki

Lance A Tatman

Martin Curran-Gray

Ajay Khoche

Gunter Steinbach

Andrew Robert Lehane

Takashi Hidai

Alexander L Tudor

Jefferson B Burch

Valery Kanevsky

Peter Mottishaw

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

A configurable probe takes advantage of inter-dependent probe control elements that pass data control signals from one controelement to the other for controlling data extraction. The control elements operate in parallel on one word at a time, based upon a state established by one of the control elements. The data to be considered is established by timing offsets dependant upon packet header lengths, and a function to be performed on the data is controlled by individual control units based upon template information individual to each control element. The probe is agnostic about protocols. It operates on stream of packet words and executes its functions according to defined templates. It is the host that controls the probe and determines what protocol header to parse and how. The controlling host instructs the probe via defined templates that act as state machine definitions what to do and when.

Programmable passive probe

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

Creating a low-bandwidth channel in a high-bandwidth channel. By taking advantage of extra bandwidth in a high-bandwidth channel, a low-bandwidth channel is created by inserting extra packets. When an inter-packet gap of the proper duration is detected, the extra packet is inserted and any incoming packets on the high-bandwidth channel are stored in an elastic buffer. Observing inter-packet gaps, minimal latency is introduced in the high-bandwidth channel when there is no extra packet in the process of being sent, and the effects of sending a packet on the low-bandwidth channel are absorbed and distributed among other passing traffic.

Creating a low bandwidth channel within a high bandwidth packet stream

According to one embodiment, a method comprises capturing, by an eavesdropping device, a packet communicated over a communication network. The eavesdropping device scans the packet's payload, and determines if an identifier is included in the packet's payload that identifies the packet as containing content of interest to the eavesdropping device. Based at least in part on determining that the packet's payload includes such identifier, the eavesdropping device uses the content of interest contained in the packet's payload. In one embodiment, a method comprises forming a packet containing content intended for an eavesdropping device, wherein the packet includes a header portion and a payload portion. The payload portion comprises a) a predefined identifier that identifies the packet as containing the content intended for the eavesdropping device, b) the content intended for the eavesdropping device, and c) an authentication token. The packet is directed via a communication network to a destination.

Protocol-generic eavesdropping network device

A system and method for measuring network performance include a first element in a network, the first element operable to receive a data packet and to create a clone packet based on the data packet, the clone packet having a destination the same as a destination of the data packet and having information identifying the clone packet as a clone, the first element operable to insert the clone packet into a data stream with the data packet.

System and method for measuring network performance using real network traffic

Packet tracing in switched packet networks. Tracing of live packet data in a network is performed by discovering the measurement path, setting up dynamic filters along the path to collect traffic information, and collecting data as detected by the dynamic filters. Collected data is sent to a measuring entity. Filter setup may be repeated to capture data as routing changes.

Packet tracing using dynamic packet filters

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

A routing monitor is disclosed comprising at least one communication tap, wherein each of the at least one communication taps is positioned in a line of communication between two routers and a protocol emulator for reassembling routing protocol messages captured by the at least one communication tap and opening a routing protocol connection with a network device using the reassembled routing protocol messages in response to a request for connection received from the network device.

Routing monitoring

Apparatus for making legacy network elements transparent to IEEE 1588 Precision Time Protocol operation. Network elements are wrapped by device(s) capable of providing either transparent clock or boundary clock operation. In one embodiment, smart interface converters are used to provide transparent clock or boundary clock operation. The smart interface converters work cooperatively.

Method and apparatus for establishing IEEE 1588 clock synchronization across a network element comprising first and second cooperating smart interface converters wrapping the network element

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

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.

Systems and methods for synchronizing time across networks

Discovering routing policies in information networks. Large networks such as Autonomous Systems are abstracted as a single network element. A plurality of taps on the borders of the abstracted element filter ingress/egress data which is forwarded for collection and correlation. By correlating information from different taps, routing policies are discovered. These discovered policies may be compared with published policies. Access control makes discovered policies and the comparisons with published policies selectively available depending on predefined access classes.

Growing community of inventors

Los Altos Hills, CA, United States of America

Slawomir K Ilnicki