Abstract: System and method to detect video quality degradation in a video stream received by a telecommunications endpoint, the method including: locating reference features characteristic of content in the received video stream; calculating reduced reference features from the located reference features; receiving reduced reference features of a transmitted video stream, the transmitted video stream corresponding to the received video stream; calculating a distance between the reduced reference features in the received video stream and the reduced reference features of the transmitted video stream; and detecting video quality degradation when the calculated distance exceeds a predetermined threshold.

Abstract: A technique that seeks to direct and re-direct streams of packets through a packet network without adversely affecting the quality of service of existing streams is disclosed. In accordance with the illustrative embodiment of the present invention, streams of packets that are directed and re-directed through a packet network are initially put on probation. During the probation period, a quality-of-service measure for the stream is compared with a threshold whose value is initially high and decreases with time. This has the advantageous affect of noticing problems quickly so that they can be remediated quickly.

Abstract: Disclosed herein are systems, methods, and non-transitory computer-readable storage media for variable video degradation counter-measures. A system configured according to this disclosure transmits a video communication over a network, detects the video quality degradation of the video communication, selects an appropriate counter-measure based at least in part on the particular type of degradation encountered, and implements the appropriate counter-measure. If multiple transmission paths are available in the system, either completely or partially disjoint, the paths can be evaluated based on ability to deliver video traffic. Throughout the transmission the system continues measuring and monitoring the video quality in real-time. The system can also accurately respond to the type and degree of the degradation by matching the type and degree of degradation to a table containing corresponding counter-measures.

Abstract: A method to determine when to compare original data (such as the original image) to rendered data (such as the rendered image) for the purpose of determining the fidelity of without some of the disadvantages of the prior art is disclosed. This is done by assessing the quality of service of a network path at a given time or by assessing the conditions of the network path over time and deciding specific times at which to test.

Abstract: A method is disclosed for conducting a search in which measurements of a time-varying property are made and updated during the search, and in which the measurements might be uncertain. In accordance with the illustrative embodiment, one or more search algorithm parameters (e.g., the maximum branching factor of a search tree, a depth cutoff for a search tree, a time cutoff, a threshold, etc.) are adjusted dynamically during the search based on at least one of: the degree of uncertainty of the measurements, the variability of measurements over time (e.g., standard deviation, etc.), and the fraction of members whose measurement is better than a threshold. In addition, the illustrative embodiment enables the search space to be pruned based on these criteria.

Abstract: A technique is disclosed that evaluates a network path between (i) a first node in a first subnetwork of endpoint nodes, such as IP phones, and (ii) a second node in a second subnetwork. A “ricochet” node in the network path evaluates the path by probing one or both subnetworks, where the ricochet node acts as relay for traffic packets being transmitted between the two subnetworks. A given relay has only to probe a single, representative node within a subnetwork at any given time in order to obtain performance data that is representative of the subnetwork overall. By probing the representative node, the relay is able to acquire an assessment of network conditions that is valid for the path between the relay and any endpoint in the subnetwork. As a result, the disclosed technique reduces the probing overhead when many endpoint nodes on a given subnetwork are simultaneously active and experiencing adverse network conditions.

Abstract: Disclosed herein are systems, methods, and non-transitory computer-readable storage media for approximating video transmission quality capability through a communications network. Initially, a processor is used to insert data into the network through a first endpoint that is delivered to a second endpoint. Then, at least one characteristic of the network between the first and second endpoints is determined based on how the second endpoint receives the data. After the at least one characteristic is determined, a representative video segment is selected based on the at least one characteristic. Finally, the representative video segment is output to demonstrate the video transmission quality capabilities of the network.

Abstract: 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.

Abstract: A method is disclosed for adaptively and intelligently partitioning traffic among a plurality of communications channels, without injecting probe traffic into any of the channels. In accordance with the illustrative embodiment, a source node transmits traffic to a receiving node via K communications channels in accordance with partition coefficients ?1, . . . , ?K, and the source node receives information regarding the quality of service (QoS) provided by each of the communications channels. The source node adjusts the values of the partition coefficients ?1, . . . , ?K adaptively based on: the current channel QoS information, prior channel QoS information, the prior values of ?1, . . . , ?K, and a measure of channel independence for one or more pairs of communications channels.

Abstract: A method to determine when to compare original data (such as the original image) to rendered data (such as the rendered image) for the purpose of determining the fidelity of without some of the disadvantages of the prior art is disclosed. This is done by assessing the quality of service of a network path at a given time or by assessing the conditions of the network path over time and deciding specific times at which to test.

Abstract: 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.

Abstract: A method is disclosed for conducting a search in which measurements of a time-varying property are made and updated during the search, and in which the measurements might be uncertain. In accordance with the illustrative embodiment, one or more search algorithm parameters (e.g., the maximum branching factor of a search tree, a depth cutoff for a search tree, a time cutoff, a threshold, etc.) are adjusted dynamically during the search based on at least one of: the degree of uncertainty of the measurements, the variability of measurements over time (e.g., standard deviation, etc.), and the fraction of members whose measurement is better than a threshold. In addition, the illustrative embodiment enables the search space to be pruned based on these criteria.

Abstract: A method is disclosed for adaptively and intelligently partitioning traffic among a plurality of communications channels, without injecting probe traffic into any of the channels. In accordance with the illustrative embodiment, a source node transmits traffic to a receiving node via K communications channels in accordance with partition coefficients ?1, . . . , ?K, and the source node receives information regarding the quality of service (QoS) provided by each of the communications channels. The source node adjusts the values of the partition coefficients ?1, . . . , ?K adaptively based on: the current channel QoS information, prior channel QoS information, the prior values of ?1, . . . , ?K, and a measure of channel independence for one or more pairs of communications channels.

Abstract: 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.

Abstract: 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.

Abstract: A technique is disclosed that attempts to improve the evaluation of a network path's signal quality, as well as the selection of a network path for transmission purposes, without some of the costs and disadvantages of doing so in the prior art. In accordance with the illustrative embodiment, a node with access to the packet network, such as a VoIP telephone endpoint, evaluates the quality of service that is associated with each of multiple network paths. The evaluation process is iterative, in which the number of candidate paths is successively reduced from one iteration of the technique to the next. The multiple paths that remain as candidates in any given iteration are evaluated concurrently and at an evaluation bit rate that i) is less than the full transmission rate of the real-time traffic (VoIP) packets to be sent and ii) varies as a function of the number of candidate paths remaining under consideration.

Abstract: A system for monitoring traffic on a network first discovers the network so as to map the various devices and links in the network. Statistics are then gathered from various points in the network relating to quality of service, and especially loads on the network devices. Synthetic calls are generated at selected points of the network while monitoring the network. This data is then stored and displayed in a manner that is easy for the operator to analyze, with more detailed displays being available through the use of a mouse or keystrokes.

Abstract: A method and apparatus are disclosed for redirecting traffic associated with an application so that the traffic advantageously traverses (or “hairpins”) through an application-layer gateway. Because the present invention advantageously redirects traffic without any participation by routers, no changes to or replacement of routers in a network is required. The illustrative embodiment is disclosed in the context of Internet telephony, but is also applicable to other kinds of applications and types of communication (e.g., Internet Protocol Television [IPTV], instant messaging [IM], videoconferencing, etc.

Abstract: 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.

Abstract: 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.