Abstract: A network monitoring and analysis system is configured to include a root cause analysis function that permits the automatic determination of performance problem locations in a network of a communication system comprising a plurality of endpoint devices. Test communications are generated in the system in accordance with a selected pattern, which may be based on a flow matrix, and end-to-end path measurement data is collected utilizing the generated test communications. The end-to-end path measurement data is transformed to produce a plurality of performance indicators comprising a performance indicator for each of a plurality of non-end-to-end paths defined at least in part by the selected pattern.

Abstract: 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.

Abstract: 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.

Abstract: 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, an endpoint device of the system includes an integrated call synthesis capability. More particularly, the endpoint device is configurable into at least a first mode of operation in which the device responds to one or more commands from a testing server of the system directing the device to participate in a synthetic call or other test communication within the system, and a second mode of operation in which the device is utilizable by a system user to establish an actual communication. Other aspects of the invention relating to kernel timestamping and timestamp post-processing provide improved accuracy for measurements such as jitter, loss and delay.

Abstract: A system discovers the topology of devices in a network, such as all of the layer-2 and layer-3 devices, including routers and switches. The devices are mapped, as well as the links that join them. The devices are polled using SNMP requests. Route tables are derived from each router to determine addresses of the devices. A spanning tree process is used to discover layer-2 devices. Connections between layers are then discovered. Where information is incomplete, an undiscovered router cloud is recognized.

Abstract: A system visualizes and generates reports from stored data, concerning various measured parameters related to a network carrying call traffic. The network is displayed in an easily recognized arrangement, with various parameters being indicated by different shapes and colors for each device on the network. The parameters are changed to indicate the status of the network at different times. More detailed information about a parameter, a device or a path between devices may be obtained simply using a mouse or keystrokes. A variety of different types of detailed displays allows the operator to troubleshoot problems in the network.

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.