Abstract: Methods and apparatus to bound network traffic estimation error for multistage measurement sampling and aggregation are disclosed.

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 ? 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.

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: The invention relates to streaming algorithms useful for obtaining summaries over unaggregated packet streams and for providing unbiased estimators for characteristics, such as, the amount of traffic that belongs to a specified subpopulation of flows. Packets are sampled from a packet stream and aggregated into flows and counted by implementation of: (a) Adaptive Sampled NetFlow (ANF), and adjusted weight (AANF) of a flow (f) is calculated as follows: AANF(f)=i(f)/p?; i(f) being the number of packets counted for a flow f, and p? being the sampling rate at end of a measurement period; or (b) Adaptive Sample-and-Hold (ASH), and adjusted weight (AASH) of a flow (f) is calculated as follows: AASH(f)=i(f)+(1?p?)/p?; i(f) being the number of packets counted for a flow f, and p? being the sampling rate at end of a measurement period.

Abstract: A method and apparatus for processing top-k queries are disclosed. For example, the method receives a top-k query with a value for a number of samples and a value of a confidence parameter. The method samples in accordance to the number of samples, and determines a top-k weight of a sample top-k set. The method bounds the top-k weight in an interval having an upper bound and a lower bound such that the top-k weight is in the interval with a probability equal to one minus the value of the confidence parameter, and provides a response to the top-k query in accordance with the upper and lower bounds.

Abstract: The invention relates to streaming algorithms useful for obtaining summaries over unaggregated packet streams and for providing unbiased estimators for characteristics, such as, the amount of traffic that belongs to a specified subpopulation of flows. Packets are sampled from a packet stream and aggregated into flows and counted by implementation of Adaptive Sample-and-Hold (ASH) or Adaptive NetFlow (ANF), adjusting the sampling rate based on a quantity of flows to obtain a sketch having a predetermined size, the sampling rate being adjusted in steps; and transferring the count of aggregated packets from SRAM to DRAM and initializing the count in SRAM following adjustment of the sampling rate.

Abstract: Methods and apparatus to bound network traffic estimation error for multistage measurement sampling and aggregation are disclosed.

Abstract: Methods and systems for estimate derivation are described. In one embodiment, a query may be received with a predicate for sets over a collection of items. Associated samples associated with the query may be accessed. Items of an associated sample may be accessed from the collection of items. A determination of whether the predicate is an attribute-based selection from a union of at least some sets may be made. Available items of the particular associated sample may be selected from the items. Identified items may be identified among the available items in the associated sample that satisfy the predicate. An adjusted weight may be assigned to an item based on a weight of the item and a distribution of the associated samples. An estimate may be generated based on the adjusted weight of the identified items of the associated samples that satisfy the predicate. Additional methods and systems are disclosed.

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: A request is received at a resource server for a first resource, the request accompanied by a proxy filter. A second resource is identified based on the proxy filter and based on a relationship between the first resource and the second resource. The first resource and information regarding the second resource is provided to a network interface for communication to a proxy server.

Abstract: A method and apparatus provide improved cache coherency and more effective caching operations without placing an undue burden on network links. A proxy receives a request for a resource and then, depending on information in the proxy cache, generates a resource request for transmission to a resource server. The proxy appends a proxy filter to the request. The resource server maintains one or more volumes of resources based on some predetermined criterion that can be either static or dynamic in nature. Upon receipt of the request and the proxy filter the resource server generates a request response and a piggybacked list of additional resources selected from the volume with which the requested resource is associated.

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: The invention relates to streaming algorithms useful for obtaining summaries over unaggregated packet streams and for providing unbiased estimators for characteristics, such as, the amount of traffic that belongs to a specified subpopulation of flows. Packets are sampled from a packet stream and aggregated into flows and counted by implementation of: (a) Adaptive Sampled NetFlow (ANF), and adjusted weight (AANF) of a flow (f) is calculated as follows: AANF(f)=i(f)/p?; i(f) being the number of packets counted for a flow f, and p? being the sampling rate at end of a measurement period; or (b) Adaptive Sample-and-Hold (ASH), and adjusted weight (AASH) of a flow (f) is calculated as follows: AASH(f)=i(f)+(1?p?)/p?; i(f) being the number of packets counted for a flow f, and p? being the sampling rate at end of a measurement period.

Abstract: The invention relates to streaming algorithms useful for obtaining summaries over unaggregated packet streams and for providing unbiased estimators for characteristics, such as, the amount of traffic that belongs to a specified subpopulation of flows. Packets are sampled from a packet stream and aggregated into flows and counted by implementation of Adaptive Sample-and-Hold (ASH) or Adaptive NetFlow (ANF), adjusting the sampling rate based on a quantity of flows to obtain a sketch having a predetermined size, the sampling rate being adjusted in steps; and transferring the count of aggregated packets from SRAM to DRAM and initializing the count in SRAM following adjustment of the sampling rate.

Abstract: A method and apparatus for provide highly efficient traffic routing for a wide range of possible traffic matrices (TM) in an intra-domain network. That routing optimally balances the traffic loads over a range of traffic matrices so as to minimize the deviation for any particular traffic matrix from the optimal routing. Such a routing provides a guaranteed performance ratio against the best possible network routing. The invention utilizes a method of optimally configuring a traffic network based on solving a linear program to obtain the optimal routing, and then configuring the routing on the network accordingly.

Abstract: A method and apparatus for provide highly efficient traffic routing for a wide range of possible traffic matrices (TM) in an intra-domain network. That routing optimally balances the traffic loads over a range of traffic matrices so as to minimize the deviation for any particular traffic matrix from the optimal routing. Such a routing provides a guaranteed performance ratio against the best possible network routing. The invention utilizes a method of optimally configuring a traffic network based on solving a linear program to obtain the optimal routing, and then configuring the routing on the network accordingly.

Abstract: A method and apparatus provide improved cache coherency and more effective caching operations without placing an undue burden on network links. A proxy receives a request for a resource and then, depending on information in the proxy cache, generates a resource request for transmission to a resource server. The proxy appends a proxy filter to the request. The resource server maintains one or more volumes of resources based on some predetermined criterion that can be either static or dynamic in nature. Upon receipt of the request and the proxy filter the resource server generates a request response and a piggybacked list of additional resources selected from the volume with which the requested resource is associated.

Abstract: A method and apparatus provide improved cache coherency and more effective caching operations without placing an undue burden on network links. A proxy receives a request for a resource and then, depending on information in the proxy cache, generates a resource request for transmission to a resource server. The proxy appends a proxy filter to the request. The resource server maintains one or more volumes of resources based on some predetermined criterion that can be either static or dynamic in nature. Upon receipt of the request and the proxy filter the resource server generates a request response and a piggybacked list of additional resources selected from the volume with which the requested resource is associated.

Abstract: In accordance with aspects of the invention, “low-level” caches can utilize source selection while non-authoritative sources can take advantage of rejuvenation to alleviate what the inventor refers to as “age penalty” and thereby reduce validation traffic.

Abstract: In accordance with aspects of the invention, “low-level” caches can utilize source selection while non-authoritative sources can take advantage of rejuvenation to alleviate what the inventor refers to as “age penalty” and thereby reduce validation traffic.