Abstract: Example scalable multi-protocol label switching (MPLS) based virtual private networks (VPNs) and methods to implement the same are disclosed. A disclosed example spoke provider edge (PE) router for an MPLS-based VPN includes a truncated virtual routing and forwarding (VRF) table containing a first value referencing a hub PE router and a second value referencing a first customer edge (CE) router coupled to the VPN via the PE router, and a forwarding module to forward a packet received from the first CE router to the hub PE router when the packet contains an address referencing a second CE router coupled to the VPN via a second spoke PE router.

Abstract: The present invention is directed to a method and system for deriving traffic demands for a packet-switched network. A novel model of defining traffic demands as a volume of load originating from an ingress link and destined to a set of egress links enables support for traffic engineering and performance debugging of large operational packet-switched networks.

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: Disclosed herein are systems, computer-implemented methods, and computer-readable media for sampling network traffic. The method includes receiving a desired quantity of flow record to sample, receiving a plurality of network flow record each summarizing a network flow of packets, calculating a hash for each flow record of based on one or more invariant part of a respective flow, generating a quasi-random number from the calculated hash for each respective flow record, generating a priority from the calculated hash for each respective flow record, and sampling exactly the desired quantity of flow records, selecting flow records having a highest priority first. In one aspect, the method further partitions the plurality of flow records into groups based on flow origin and destination, generates an individual priority for each partitioned group, and separately samples exactly the desired quantity of flow records from each partitioned group, selecting flows having a highest individual priority first.

Abstract: Disclosed herein are systems, computer-implemented methods, and computer-readable media for sampling network traffic. The method includes receiving a plurality of flow records, calculating a hash for each flow record based on one or more invariant part of a respective flow, generating a quasi-random number from the calculated hash for each respective flow record, and sampling flow records having a quasi-random number below a probability P. Invariant parts of flow records include destination IP address, source IP address, TCP/UDP port numbers, TCP flags, and network protocol. A plurality of routers can uniformly calculate hashes for flow records. Each router in a plurality of routers can generate a same quasi-random number for each respective flow record and uses different values for probability P. The probability P can depend on a flow size. The method can divide the quasi-random number by a maximum possible hash value.

Abstract: A system and method to use network flow records to generate information about changes in network routing and to understand the impact of these changes on network traffic. The inferences made can be determinative, if sufficient information is available. If sufficient information is not available to make determinative inferences, inferences may be made that narrow the range of possible changes that may have occurred to network traffic and the underlying network.

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

Abstract: A system includes an information storage module and an inspection module. The information storage module is configured to store a plurality of tags. Each tag is associated with a known set of traffic types of a plurality of known sets of traffic types. The inspection module is configured to compare a traffic flow to a set of traffic types to determine a matching set of traffic types, request a tag from the information storage module, and mark the traffic flow with the tag. The tag corresponds to the matching set of traffic types.

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: Methods and apparatus to dynamically control access from VPNs to shared resources are disclosed. A disclosed example route reflector comprises a memory to implement a database, a user interface module to receive a request to permit access for a VPN to a shared resource, a BGP engine to process BGP advertisements, a network interface to receive a first BGP advertisement from a PE router associated with the VPN that includes a first RT associated with the VPN, and a shared resource access controller to update the database based on the request, to query the database to determine whether the VPN has access to the shared resource in response to the first BGP advertisement, and to direct the BGP engine to form a second BGP advertisement based on the first BGP advertisement that includes a second RT associated with the shared resource when the VPN has access to the shared resource.

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 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: 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 present invention relates to methods and devices for providing a reduced risk of free flow from medical devices such as an infusion pump. A medicament containing reservoir is provided with a piston having a sealing portion formed by a material of a first stiffness. The piston further comprises a frictional enhancing member having one or more reservoir wall engaging portions and being at least partly made of a material having a stiffness greater than the first stiffness. By arranging the frictional enhancing member to exert a radially outwards directed force component against the cylindrical wall an increased friction is provided between the piston and the reservoir wall.

Abstract: Example scalable multi-protocol label switching (MPLS) based virtual private networks (VPNs) and methods to implement the same are disclosed. A disclosed example spoke provider edge (PE) router for an MPLS-based VPN includes a truncated virtual routing and forwarding (VRF) table containing a first value referencing a hub PE router and a second value referencing a first customer edge (CE) router coupled to the VPN via the PE router, and a forwarding module to forward a packet received from the first CE router to the hub PE router when the packet contains an address referencing a second CE router coupled to the VPN via a second spoke PE router.

Abstract: A method of assigning a server to a client system includes determining an ingress point of the client system and identifying possible egress points for the client system. The method further includes selecting the server from a plurality of servers to reduce network cost and delivery time.

Abstract: The present application relates to methods and devices for providing a reduced risk of free flow from medical devices such as an infusion pump. A medicament containing reservoir (100) is provided with a piston having a sealing portion (121) formed by a material of a first stiffness. The piston further comprises a core member (110) of a material having a stiffness larger than said first stiffness, the core member comprising one or more connective members (111) being adapted to cooperate with said one or more protrusions of the linear actuation member. The one or more connective members being adapted to be substantially rigid in the axial direction while being resilient in a radial direction, thereby forming a releasable snap or friction fit connection with the linear actuation member.

Abstract: Two regularized estimators that avoid the pathologies associated with variance estimation are disclosed. The regularized variance estimator adds a contribution to estimated variance representing the likely error, and hence ameliorates the pathologies of estimating small variances while at the same time allowing more reliable estimates to be balanced in the convex combination estimator. The bounded variance estimator employs an upper bound to the variance which avoids estimation pathologies when sampling probabilities are very small.

Abstract: Two regularized estimators that avoid the pathologies associated with variance estimation are disclosed. The regularized variance estimator adds a contribution to estimated variance representing the likely error, and hence ameliorates the pathologies of estimating small variances while at the same time allowing more reliable estimates to be balanced in the convex combination estimator. The bounded variance estimator employs an upper bound to the variance which avoids estimation pathologies when sampling probabilities are very small.