Avaya Inc.

Avaya Technology LLC

Balaji Sathyanarayana Rao

Jean Meloche

Lorraine Denby

Akshay Adhikari

John R Tuck, Jr

Eric John Diethorn

Bengi Karacali-Akyamac

Colin Lingwood Mallows

Parameshwaran Krishnan

Mark John Karol

Jay Munro Stiles

Scott Vincent Bianco

Shane M Sullivan

Paul Blum

Yehuda Vardi

Kenneth Pearl

Anton Rager

Eric J Diethron

One or more network elements that modify type of service values in a network are detected by sending route tracing messages having increasing time-to-live values and a designated type of service value from a first network element to a second network element. Type of service values are monitored in respective time exceeded messages received from respective network elements on a given network path between the first network element and the second network element responsive to the route tracing messages. At least a particular one of the network elements on the given network path that has made a modification in type of service value relative to the designated type of service value is identified, based on the monitored type of service values in the respective time exceeded messages.

Route tracing program configured to detect particular network element making type of service modification

A network condition capture and reproduction technique captures measurement data characterizing network conditions at a given time between first and second endpoint devices of a network, and utilizes the captured measurement data in a network impairment device to reproduce the network conditions at a later time and possibly in a different place.

Network condition capture and reproduction

Performance problems or other conditions are analyzed in a system comprising a plurality of endpoint devices and an associated centralized or distributed controller. End-to-end measurements are obtained for respective paths through the network, for example, using communications between the endpoint devices. For a given end-to-end measurement obtained for a particular one of the paths, a value of a performance indicator for the path is determined and the performance indicator value is assigned to each of a plurality of links of the path. The determining and assigning operations are repeated for additional ones of the end-to-end measurements, the links are grouped into one or more exculpation or inculpation sets based on how many times a particular performance indicator value has been assigned to each of the links, and the one or more sets are utilized to determine, for example, the location of a performance problem in the network.

Root cause analysis of network performance based on exculpation or inculpation sets

An apparatus and method are disclosed that enable a first telecommunications endpoint to ensure that a second endpoint is receiving the first endpoint's packet stream transmissions with a satisfactory waveform quality. When the second endpoint receives the packet stream, it decodes the media waveform from the stream, encodes the waveform back into a second packet stream, and transmits some or all of the packets in the second stream back to the first endpoint. The first endpoint then decodes the received waveform in the second stream and compares it to the original waveform transmitted to the second endpoint. Based on the comparison, the first endpoint adjusts the value of a quality indication, and provides the quality indication to its user and to the second endpoint. Advantageously, the user at the second endpoint is able to determine whether the received waveform is, in fact, close enough to the waveform that the first endpoint's user intended to be received and understood.

Acknowledgment of media waveforms between telecommunications endpoints

A network monitoring and analysis system is configured to conduct performance analysis on a network using a plurality of endpoint devices. Locations of respective endpoint devices for use in the performance analysis of the network are determined utilizing an algorithm which characterizes the network as a graph having edges and vertices and associates endpoint devices with particular ones of the vertices in an iterative manner based on impact of said vertices on achievement of a specified coverage criterion. The coverage criterion may comprise a links-covered criterion which specifies a percentage of a total number of links of the network that are covered by test communications. As another example, the coverage criterion may comprise a links-estimable criterion which specifies a percentage of a total number of links of the network for which performance is estimable from collected end-to-end path measurement data.

Determination of endpoint device location for efficient analysis of network performance

A method for estimating the network-layer topology of a telecommunications network is described. In particular, the illustrative embodiment of the present invention estimates the existence and connectivity of nodes in the topology based on the detection of network-wide end-to-end path intersections. This is based on the assumption that pairs of streams of packets that share a common node will interfere and that the interference can be detected in the received streams. In general, this interference is manifested as jitter. By transmitting streams on each pair of end-to-end paths in the network, and detecting interference (or a lack of interference) a matrix of path intersections for the network can be created. Using logic and supposition, the topology of the network can be estimated using the matrix of path intersections. Once the estimate of the topology is complete, the maintenance and operation of the network can proceed based on the topology.

Interfering packet streams in packet networks

Node merging methods and apparatus are disclosed for generating simplified representations of network topology. A first topology representative of a given network is determined, and at least one pair of nodes of the first topology is merged into a single node based on measures associated with respective edges connecting the nodes of the node pair to at least one neighbor node common to that pair. The merging step is repeated for one or more additional pairs of nodes to produce a reduced network topology meeting one or more desired criteria, and a visualization or other representation of the reduced network topology is generated.

Node merging process for network topology representation

Network topology information is determined in a network-based communication system by generating communications between, for example, selected pairs of endpoint devices each associated with a network. A given one of the communications is sent from a first one of the endpoint devices to a second one of the endpoint devices and returned from the second endpoint device to the first endpoint device. Information contained in the communication as received at the first endpoint device from the second endpoint device is processed to determine network topology information characterizing at least a portion of the network.

Method and apparatus for determination of network topology

Techniques are disclosed for improved monitoring and analysis of VoIP communications, multimedia communications or other types of network traffic in a network-based communication system. In accordance with one aspect of the invention, endpoint devices of the network-based communication system are configurable so as to collectively implement a distributed monitoring and analysis system which does not require a centralized testing server or other centralized controller. Distributed test units associated with the endpoint devices may be utilized in implementing the distributed monitoring and analysis system, and are preferably configured to support a web-based user interface providing access to measurement data. The endpoint devices may be advantageously organized into a hierarchy comprising a plurality of zones, with each of the endpoint devices belonging to at least one zone. For each zone, one of the endpoint devices may be designated as a zone leader for controlling the periodic generation of communications between selected endpoint devices that belong to subzones of that zone in the hierarchy.

Growing community of inventors

Somerville, NJ, United States of America

Balaji Sathyanarayana Rao