Abstract:
A packet loss estimation technique is disclosed that utilizes the sampled flow level statistics that are routinely collected in operational networks, thereby obviating the need for any new router features or measurement infrastructure. The technique is specifically designed to handle the challenges of sampled flow-level aggregation such as information loss resulting from packet sampling, and generally comprises: receiving a first record of sampled packets for a flow from a first network element; receiving a second record of sampled packets for the flow from a second network element communicating with the first network element; correlating sampled packets from the flow at the first network element and the second network element to a measurement interval; and estimating the packet loss using a count of the sampled packets correlated to the measurement interval.
Abstract:
A system to detect anomalies in internet protocol (IP) flows uses a set of machine-learning (ML) rules that can be applied in real time at the IP flow level. A communication network has a large number of routers that can be equipped with flow monitoring capability. A flow collector collects flow data from the routers throughout the communication network and provides them to a flow classifier. At the same time, a limited number of locations in the network monitor data packets and generate alerts based on packet data properties. The packet alerts and the flow data are provided to a machine learning system that detects correlations between the packet-based alerts and the flow data to thereby generate a series of flow-level alerts. These rules are provided to the flow time classifier. Over time, the new packet alerts and flow data are used to provide updated rules generated by the machine learning system.
Abstract:
The present invention relates to a method of obtaining a generic sample of an input stream. The method is designated as VAROPTk. The method comprises receiving an input stream of items arriving one at a time, and maintaining a sample S of items i. The sample S has a capacity for at most k items i. The sample S is filled with k items i. An nth item i is received. It is determined whether the nth item i should be included in sample S. If the nth item i is included in sample S, then a previously included item i is dropped from sample S. The determination is made based on weights of items without distinguishing between previously included items i and the nth item i. The determination is implemented thereby updating weights of items i in sample S. The method is repeated until no more items are received.
Abstract:
The preferred embodiments of the present invention can include sampling packets transmitted over a network based on the content of the packets. If a packet is sampled, the sampling unit can add one or more fields to the sampled packet that can include a field for a number of bytes contained in the packet, a packet count, a flow count, a sampling type, and the like. The sampled packets can be analyzed to discern desired information from the packets. The additional fields that are added to the sampled packets can be used during the analysis.
Abstract:
A method and apparatus for providing performance measurements on network tunnels in packet networks are disclosed. For example, the method establishes two tunnels between a first measurement host and a first router, and establishes a tunnel between the first router and a second measurement host. The method also establishes a multicast group having a plurality of members, and sends one or more packets addressed to the multicast group from the first measurement host. The method measures the frequencies of directly and/or indirectly received responses from the plurality of members of the multicast group, and provides a plurality of estimated values for a plurality of packet transmission rates from measurement of the frequencies for one or more of said tunnels.
Abstract:
A traffic classifier has a plurality of binary classifiers, each associated with one of a plurality of calibrators. Each calibrator trained to translate an output score of the associated binary classifier into an estimated class probability value using a fitted logistic curve, each estimated class probability value indicating a probability that the packet flow on which the output score is based belongs to the traffic class associated with the binary classifier associated with the calibrator. The classifier training system configured to generate a training data based on network information gained using flow and packet sampling methods. In some embodiments, the classifier training system configured to generate reduced training data sets, one for each traffic class, reducing the training data related to traffic not associated with the traffic class.
Abstract:
In one embodiment, the present disclosure is a method and apparatus for classifying applications using the collective properties of network traffic. In one embodiment, a method for classifying traffic in a communication network includes receiving a traffic activity graph, the traffic activity graph comprising a plurality of nodes interconnected by a plurality of edges, where each of the nodes represents an endpoint associated with the communication network and each of the edges represents traffic between a corresponding pair of the nodes, generating an initial set of inferences as to an application class associated with each of the edges, based on at least one measured statistic related to at least one traffic flow in the communication network, and refining the initial set of inferences based on a spatial distribution of the traffic flows, to produce a final traffic activity graph.
Abstract:
A method for producing a summary A of data points in an unaggregated data stream wherein the data points are in the form of weighted keys (a, w) where a is a key and w is a weight, and the summary is a sample of k keys a with adjusted weights wa. A first reservoir L includes keys having adjusted weights which are additions of weights of individual data points of included keys and a second reservoir T includes keys having adjusted weights which are each equal to a threshold value τ whose value is adjusted based upon tests of new data points arriving in the data stream. The summary combines the keys and adjusted weights of the first reservoir L with the keys and adjusted weights of the second reservoir T to form the sample representing the data stream upon which further analysis may be performed. The method proceeds by first merging new data points in the stream into the reservoir L until the reservoir contains k different keys and thereafter applying a series of tests to new arriving data points to determine what keys and weights are to be added to or removed the reservoirs L and T to provide a summary with a variance that approaches the minimum possible for aggregated data sets. The method is composable, can be applied to high speed data streams such as those found on the Internet, and can be implemented efficiently.
Abstract:
A multi-staged framework for detecting and diagnosing Denial of Service attacks is disclosed in which a low-cost anomaly detection mechanism is first used to collect coarse data, such as may be obtained from Simple Network Management Protocol (SNMP) data flows. Such data is analyzed to detect volume anomalies that could possibly be indicative of a DDoS attack. If such an anomaly is suspected, incident reports are then generated and used to trigger the collection and analysis of fine grained data, such as that available in Netflow data flows. Both types of collection and analysis are illustratively conducted at edge routers within the service provider network that interface customers and customer networks to the service provider. Once records of the more detailed information have been retrieved, they are examined to determine whether the anomaly represents a distributed denial of service attack, at which point an alarm is generated.
Abstract:
A traffic classifier has a plurality of binary classifiers, each associated with one of a plurality of calibrators. Each calibrator trained to translate an output score of the associated binary classifier into an estimated class probability value using a fitted logistic curve, each estimated class probability value indicating a probability that the packet flow on which the output score is based belongs to the traffic class associated with the binary classifier associated with the calibrator. The classifier training system configured to generate a training data based on network information gained using flow and packet sampling methods. In some embodiments, the classifier training system configured to generate reduced training data sets, one for each traffic class, reducing the training data related to traffic not associated with the traffic class.