Abstract: Systems and methods are disclosed for testing a processor having at least a first interface. In one embodiment, the method includes configuring, at the processor, a second interface, such that the configured second interface has one or more quality of service parameters representative of the first interface; sending one or more packets through the configured second interface, the one or more packets being representative of another packet received at the first interface; and determining, based on the one or more packets, one or more performance parameters corresponding to the first interface under test.

Abstract: A multi-functional graphical user interface facilitates the analysis and assessment of application delays, including delays that occur on multiple paths. A trace file of an application's network events is processed to categorize the causes of delays incurred in the propagation and processing of these events. The system identifies the amount of delay (‘component delay’) that can be eliminated by eliminating each of the components of delay individually, as well as the amount of delay (‘parallel delay’) that can be eliminated by eliminating combinations of the delay components. A user interface displays the amount of reduction that can be achieved by eliminating each component delay individually and the amount of reduction that can be achieved by eliminating combinations of the individual component delays.

Abstract: Traffic flow between each pair of nodes in a network are determined based on loads measured at each link and based on gravity measures associated with each node. The gravity measures correspond to a relative likelihood of the node being a source or a sink of traffic, and may be assigned based on ‘soft’ characteristics associated with each node, such as the demographics of the region in which the node is located, prior sinking and sourcing statistics, and so on. Because the assigned gravities are relatively subjective, the gravity measures are used to generate an objective function for solving a system of linear equations, rather than as criteria that must be satisfied in the solution. The measured link loads are allocated among the traffic flows between nodes to at least a given allocation efficiency criteria by solving a system of linear equations with an objective of minimizing a difference between the assigned gravities and the resultant gravities corresponding to the determined flows.

Abstract: A network is partitioned into a set of independent partitions, and the topology of each partition is determined, then merged to form a topology of the entire network. Preferably, the partitioning is hierarchical, wherein the network is partitioned to form individual VLAN partitions, and each of the VLAN partitions is further partitioned based on the nodes that are simply connected to each port of one or more selected root switches within the VLAN partition. Simple connections to each port are efficiently determined based on an aggregate address forwarding table associated with each node. Ancillary information, such as spanning tree or CDP data, may be used to facilitate efficient partitioning and/or to validate inferences that are made with incomplete information.

Abstract: Systems and methods are disclosed for simulating network performance. In one exemplary embodiment, the method includes inferring one or more services on the network; collecting network information based on actual traffic on the network; determining a traffic generator, such that the traffic generator represents the actual traffic on the network from a perspective of at least one of the inferred services; and simulating performance of the network using the determined traffic generator and at least one of the inferred services.

Abstract: A network configuration is processed to identify each policy and the criteria associated with each policy. The criteria of the policies are processed to identify a non-overlapping set of ranges of the criteria parameter, each range being associated with a particular policy or set of policies. In a preferred embodiment, the criteria include the protocol, the source and destination IP addresses, and the source and destination ports, and a default range is defined for each criteria parameter.

Abstract: Multiple parent-dependencies are identified for messages that are received on a network that includes nodes that are configured to avoid the conventional strictly-sequential communications techniques and protocols, in order to accelerate network performance. If a network is known, or assumed, to include intermediate/proxy nodes that are configured to provide acceleration, access control, and other services, the system that analyzes traffic on the network is configured to assume that these nodes may/will provide such features, and thereby introduce multiple dependencies among the messages communicated across the network. For each message transmitted from a forwarding node, messages received at the forwarding node are assessed to distinguish messages from the destination node and messages from an other node, and a dependency is defined for each.

Abstract: A system and method optimizes the information flow regarding node location across a network by controlling the propagation of this information based on distance from the node. Location servers that are near to a node receive detailed information regarding the node's location; location servers that are farther from the node receive less detailed information. In like manner, periodic updates are provided less frequently to distant location servers, and preferably also based on the velocity of a mobile node, or on a priority associated with the mobile node. The location information provided in a message addressed to a node can be minimal when the message is transmitted, and additional detail can be added to this location information by routing nodes as the message is routed closer to its destination, based on information provided by the location servers.

Abstract: The physical connection corresponding to IP tunnels in a network are found by tracing through the device configuration and routing tables at the routers in the network to determine the outbound interface associated with each tunnel endpoint, and then inferring a likely return interface associated with the opposite tunnel endpoint. Depending upon the particular configurations, a variety of tests can be applied to validate the inference. Patricia trees are preferably used to store and process the configuration data for efficient tracing through the routing tables at each router.

Abstract: A path-flow formulation of defining MPLS FRR bypass LSPs is presented. The path-flow formulation comprises first identifying a set of candidate bypass LSPs, each of which meets various network constraints and has an explicit route around a network facility to be protected. The constraints may include Quality of Service (QoS) guarantees, implementation requirements, network element resource limitations, and resiliency requirements. The constraints may be user-selected, and may be non-linear. The set of candidate bypass LSPs form a linear programming (LP) problem, or an integer linear programming (ILP) problem if the allowable number of bypass LSPs is constrained. In an optimization step, LP solutions are used to select the bypass LSPs from among the candidate bypass LSPs by allocating bandwidth to them.

Abstract: A system and method to visually navigate hierarchical data groups are provided. If a user wishes to graphically view network traffic data for a particular business group of network nodes, a network topology navigation tool may be provided to display to the user such information that is relevant to the selected business group and the corresponding hierarchy level. The user may also be permitted to access more detailed connection information through appropriate drill-downs.

Abstract: A graphic user interface facilitates the hierarchical analysis of timing parameters related to network-based applications. At the top level of the hierarchy, the user is presented a summary of the delays incurred while running an application, or while simulating the running of an application, organized by delay categories, including processing delays at each node, as well as propagation delays at each link between nodes. The interface enables a user to “drill down” into lower levels of the timing information hierarchy by ‘clicking’ on currently displayed information. The information is presented in a form most appropriate to the level of analysis. The presentation forms include, for example, pie-charts, multi-variable timing diagrams (in both absolute and relative forms), data exchange charts, and so on, and ‘zoom’ capabilities are provided as appropriate to the particular display form.

Abstract: Systems and methods are disclosed for managing services on a network. In one exemplary embodiment, the method includes receiving topologically relevant network information concerning nodes, interfaces, connections and/or protocols; resolving conflicts in the received information; determining and storing a network topology from the received and resolved information; and inferring one or more services based on the stored topology.

Abstract: First-order effects of hypothesized fault conditions are determined by propagating discrete test packets between select nodes and noting the change of path, if any, taken by the test packet under each condition relative to the fault-free path. Tools are provided to create classes of node pairs of interest, and test packets are created only for select classes. The network is analyzed to identify fault conditions that are likely to impact system performance, and only these fault conditions are simulated. By providing a methodology for selecting classes of node pairs to test, and prioritizing the faults to simulate, a first-order survivability analysis of large networks can be performed efficiently and effectively. The efficiency of this technique is also enhanced by providing test packets that are representative of a wide range of possible source-destination combinations, and by evaluating only the source-destination combinations that may be directly affected by each fault condition.

Abstract: Channel access delays and reception uncertainty are modeled as protocol-independent generic processes that are optimized for improved simulation performance. The generic process components are designed such that each different protocol can be modeled using an arrangement of these components that is specific to the protocol. In this way, speed and/or accuracy improvements to the generic process components are reflected in each of such protocol models. If an accurate analytic model is not available for the generic process component, a prediction engine, such as a neural network, is preferably used. The prediction engine is trained using the existing detailed models of network devices. Once trained, the prediction engine is used to model the generic process, and the protocol model that includes the generic component is used in lieu of the detailed models, thereby saving substantial processing time.

Abstract: Time-varying latency is estimated based on the round-trip time between the time of sending a message and the time of receiving an acknowledgement of receipt of the message. The round-trip time relative to a transmitter is modeled as a combination of known, or determinable, delays, plus an unknown latency, plus a processing/acknowledgement delay at the receiver. The estimated time-varying latency is further refined to give more weight to estimates based on fewer unknowns or a lesser magnitude of unknowns, and to impose physical constraints, such as assuring that the estimate does not imply an unrealizable event. TCP-specific constraints and assumptions are also applied to further refine the latency estimates.

Abstract: Application messages are segregated into message paths, and the delays of the transmitted packets associated with each message path are independently analyzed to distinguish propagation, bandwidth, congestion, and protocol delays. To further distinguish the congestion delays, all of the paths of the application messages are assessed to identify delays induced by the application, including self-congestion delay, corresponding to pre-congestion delays caused by attempting to send data from a source device faster than the bandwidth of the channel allows, and cross-congestion delay, corresponding to post-congestion delays caused by varying delays beyond a bottleneck link in the channel. The remaining congestion delay is identified as network congestion delay, corresponding to delays caused by network devices other than the source device. After identifying each of the components of delay, the effect of each component on the overall delay is determined to identify where improvements can best be made.

Abstract: An interactive system and method automates the control and management of routing changes that are focused on specific routes or particular network hot spots. Based on the premise that the user is aware of a particular problem that needs to be solved, the system leads the user through an end-to-end process from the identification of the problem to the generation of configuration instructions for effecting a selected solution. A graphic user interface provides a visualization of the current routing and alternative routings, to facilitate the analysis and selection of an improved routing, if any. Throughout the process, the effect of each proposed routing change on the overall network performance is determined, so that the selection of a preferred solution can be made in the appropriate context, and globally sub-optimal solutions can be avoided.

Abstract: A network monitoring device configured to collect a new packet from one or more observation points of a network and to compare the new packet with a list of a number of received packets based on a packet arrival rate and to identify a duplicate packet. In particular, the number of received packets in the list is equivalent to a number of packets received within a time period, i.e. the packet arrival rate. Stated differently, the network monitoring device is to compare the new packets with received packets stored in a queue of a buffer and wherein the queue has a size based on a packet arrival rate collected at one or more observation points. In addition, the time period is further adjusted according to a threshold value. The threshold value is a variable parameter that can be adjusted to compensate for different network deployment. In one embodiment, the threshold value is a time value that is not more than a transmission time of a TCP retransmitted packet.

Abstract: A Composite Pattern with BLOB data types is used to model a hierarchical network, and includes a path-like construct for locating each component within the network model. Database procedures are used to efficiently search, modify and retrieve individual nodes from the network model using the database server's memory pool so that client applications are not required to retrieve and deserialize the entire Composite-BLOB hierarchy in order to make modifications or search for individual elements, thereby substantially reducing the transfer of data between the application layer and database. To avoid the need for dynamic memory restructuring during deserialization, the size required to store component data at each composite is stored when the composite is serialized, and during deserialization, the size is retrieved and used to obtain sufficient memory for the deserialized composite.