Abstract: Node, computer software and method for selecting a resource that is available at multiple caches connected in a communication network. The method includes receiving from a user a request for the resource; identifying one or more caches of the multiple caches that store the resource; determining a total cost associated with a path between the user and each cache of the one or more caches storing the resource, the total cost including a static cost that reflects a topology of the communication network and a dynamic cost which is indicative of changing conditions of the communication network; and selecting one cache from the one or more caches that store the resource based on a lowest total cost of the one cache.

Abstract: Mechanisms for designating particular nodes in a network as measurement endpoint (MEP) nodes are disclosed. Network topology information that identifies a plurality of nodes and communication links in a network is accessed. An initial chromosome generation is established. Each chromosome in the chromosome generation comprises a structure that identifies each node in the plurality of nodes that has an MEP capability and that includes an MEP state indicator for each node. A succession of a plurality of chromosome generations are generated by evolving each chromosome generation into a successive chromosome generation based on a genetic selection function and a fitness function until a threshold condition is met. An optimal chromosome from a successive chromosome generation is determined. A configuration command is sent to each node in a subset of the nodes that configures each node to operate as a MEP node.

Abstract: A method of estimating available capacity of a data transfer path that transfers data between a sending and a receiving data communication node of a data communication system is disclosed. The method includes: sending one or more setting packets wherein the one or more setting packets is/are used to set a traffic shaping node arranged in the data transfer path in a steady state; transmitting, from the traffic shaping node, probe packets received from the sending node, towards the receiving node at an average rate for the traffic shaping node; providing, in response to traversal of the data transfer path by the probe packets, and during the real-time operation of the data transfer path, measured data for use in estimating the available capacity of the data transfer path; and estimating the available capacity of the data transfer path using the measured data from the probe packets.

Abstract: A method for queuing data packets is described. Upon receipt of a data packet, e.g., at an egress buffer of a node, a position within an output queue at which to place the data packet is determined. The queue position for the data packet can be determined based on various criteria, e.g., the type of the data packet and a time associated with its subsequent transmission, and timing aspects associated with the data packets which are already stored in the queue.

Abstract: An Admission Control Node and a method performed thereby for enabling a measurement between a first and a second device in a communication network, and a first device and a method performed thereby for performing the measurement between the first device and the second device in a communication network are provided. The method in the Admission Control Node comprises receiving, from the first device, a request for performing the measurement between the first and the second device and, determining segments comprised in a path between the first and the second device. The method also comprises determining a current measurement situation for the segments, and deciding to allow or reject the request for performing the measurement based on the current measurement situation for the segments. The method further comprises informing the first device about the decision of allowing or rejecting the request for performing the measurement.

Abstract: A method and device for determining the presence of a rate limiting mechanism arranged between a sending and a receiving data communication node in a data transfer path of a communication network is presented. The method includes determining time difference values for probe packets in a train of probe packets sent from the sending node and received in the receiving node after having traversed the data transfer path during real-time operation of the data transfer path. The method further includes determining the presence of a rate limiting mechanism in the data transfer path upon detecting that an increase in the time difference value between received probe packets in the train of probe packets exceeds a threshold criterion. Other methods and devices for determining the absence of a rate limiting mechanism and corresponding computer program products are further disclosed.

Abstract: A method performed by a hypervisor executing a virtual machine for enabling a performance measurement between the virtual machine and a peer node, and a method performed by a physical machine comprising the hypervisor are provided. The method performed by the hypervisor comprises intercepting a packet transmitted from, or destined to, the virtual machine, the packet comprising a destination address to the virtual machine or to the peer node, and determining whether to insert a hypervisor time stamp or not in the packet. The method further comprises, when it is determined to insert the hypervisor time stamp in the packet, inserting a hypervisor time stamp in the packet, and forwarding the packet to its destination according to the destination address.

Abstract: An apparatus (100), a method (200) and a computer program (910) are provided for monitoring a connectivity service in a transport network (170). The apparatus (100) comprises an obtaining unit (120), adapted to request and obtain, for the connectivity service, a Service Definition and Measurement Points, MPs. The Service Definition comprises a set of measurable parameters. The obtaining unit (120) is further adapted to request and obtain a mapping of each of the measurable parameter(s) to Operation Administration and Monitoring function(s), OAM function(s), of the connectivity service. The obtaining unit (120) is further adapted to request and obtain a mapping of the measurable parameter(s) and OAM-function(s) to which tool(s) to use for measuring the measurable parameter(s) of the connectivity service. The apparatus (100) further comprises a measuring unit (130), adapted to perform measurement of the measurable parameter(s) between the Measurement Points using the tool(s).

Abstract: Mechanisms for monitoring communication links in a network are disclosed. A device receives a plurality of path performance indicators over a period of time. It is determined that at least some of the path performance indicators identify a path violation in a corresponding path of a plurality of paths in the network. For each path performance indicator that identifies a path violation, a communication link value associated with each communication link in the corresponding path is updated based on a path violation value. The device identifies at least one particular communication link as a problematic communication link based on a comparison between a problematic link criterion and the communication link value associated with the at least one particular communication link.

Abstract: Node, computer software and method for selecting a resource that is available at multiple caches connected in a communication network. The method includes receiving from a user a request for the resource; identifying one or more caches of the multiple caches that store the resource; determining a total cost associated with a path between the user and each cache of the one or more caches storing the resource, the total cost including a static cost that reflects a topology of the communication network and a dynamic cost which is indicative of changing conditions of the communication network; and selecting one cache from the one or more caches that store the resource based on a lowest total cost of the one cache.

Abstract: According to one exemplary embodiment, a method for determining the forward and reverse available capacity or tight link capacity of an IP path from a single endpoint includes the steps of: transmitting, from a source IP endpoint node toward a destination IP endpoint node, a forward packet train including a first plurality of IP test packets over the forward IP path; and receiving, at the source IP endpoint node, a corresponding reverse packet train from the destination IP endpoint node, the reverse packet train including a second plurality of IP test packets over the reverse IP path each of which correspond to a respective one of the first plurality of IP test packets. For those IP path capacity measurements embodiments which are TWAMP-based, no changes are needed to the TWAMP control protocol, e.g., since exemplary embodiments make use of padding octets to transfer additional information which can be used for available IP path capacity and tight IP link capacity calculations.

Abstract: A method of estimating available capacity of a data transfer path that transfers data between a sending and a receiving data communication node of a data communication system is disclosed. The method includes: sending one or more setting packets wherein the one or more setting packets is/are used to set a traffic shaping node arranged in the data transfer path in a steady state; transmitting, from the traffic shaping node, probe packets received from the sending node, towards the receiving node at an average rate for the traffic shaping node; providing, in response to traversal of the data transfer path by the probe packets, and during the real-time operation of the data transfer path, measured data for use in estimating the available capacity of the data transfer path; and estimating the available capacity of the data transfer path using the measured data from the probe packets.

Abstract: The present invention relates to methods and node entities for enabling active measurement for evaluating network performance in a network comprising a logical tree structure 10 representing at least one service. Said service is provided through a set of links from an initial node in an upper level of the tree structure to a node in a lower level of said tree structure. Each node of the tree structure is configured to perform active measurement of link characteristics. One object of the present invention is to provide a method for minimizing the data overhead introduced in a data network during measuring of estimates of the data network performance. By aggregating measurement results of estimated and measured link characteristics in the nodes of said tree structure and propagating the aggregated results and store the aggregated results in the nodes.

Abstract: Embodiments of the present invention relate to a method and system to monitor network performance in a computer including at least one physical server having a hardware machine attached via a hypervisor to a set of virtual machines. According to an embodiment of the present invention, the system measures network performance parameters for selected packet flows in transition between the hardware machine and the virtual machines, analyzes the measured performance parameters, and identifies a source of network degradation.

Abstract: Node, computer software and method for selecting a resource that is available at multiple caches connected in a communication network. The method includes receiving from a user a request for the resource; identifying one or more caches of the multiple caches that store the resource; determining a total cost associated with a path between the user and each cache of the one or more caches storing the resource, the total cost including a static cost [Cf] that reflects a topology of the communication network and a dynamic cost [?] which is indicative of changing conditions of the communication network; and selecting one cache from the one or more caches that store the resource based on a lowest total cost of the one cache.

Abstract: A method and apparatus for estimating available capacity of a data transfer path (16) that transfers data between data communication nodes (12, 14) of a data communication system (10). The method comprising: receiving (305) probe packets (15) that traverse the data transfer path (16) during real-time operation of the data transfer path (16); providing (310) measured data (zU, zE) indicating strain of the received probe packets for use in estimating the available capacity of the data transfer path (16); classifying (320) the measured data based on the strain of the received probe packets; filtering (325) the classified measured data into a discrete representation of a probability density function of available capacity; and estimating (330) the available capacity by using the discrete representation of the probability density function.

Abstract: According to one exemplary embodiment, a method for determining the forward and reverse available capacity or tight link capacity of an IP path from a single endpoint includes the steps of: transmitting, from a source IP endpoint node toward a destination IP endpoint node, a forward packet train including a first plurality of IP test packets over the forward IP path; and receiving, at the source IP endpoint node, a corresponding reverse packet train from the destination IP endpoint node, the reverse packet train including a second plurality of IP test packets over the reverse IP path each of which correspond to a respective one of the first plurality of IP test packets. For those IP path capacity measurements embodiments which are TWAMP-based, no changes are needed to the TWAMP control protocol, e.g., since exemplary embodiments make use of padding octets to transfer additional information which can be used for available IP path capacity and tight IP link capacity calculations.

Abstract: A method that reduces the power consumption on network nodes by taking into account the services that need to be supported by the network and the power saving capabilities of the nodes.

Abstract: The present invention relates to a method and arrangement for estimating available bandwidth of sub-path of a data path. The solution is based on the sending of probe packet trains comprising inner and outer packets from a start node to an end node using different TTL values for the outer and inner packets of these probe trains. By comparing measurements using different TTL values of the inner packets, it is also possible to determine which link are the local tight link and what available bandwidth it has.

Abstract: A method and device for determining the presence of a rate limiting mechanism arranged between a sending and a receiving data communication node in a data transfer path of a communication network is presented. The method includes determining time difference values for probe packets in a train of probe packets sent from the sending node and received in the receiving node after having traversed the data transfer path during real-time operation of the data transfer path. The method further includes determining the presence of a rate limiting mechanism in the data transfer path upon detecting that an increase in the time difference value between received probe packets in the train of probe packets exceeds a threshold criterion. Other methods and devices for determining the absence of a rate limiting mechanism and corresponding computer program products are further disclosed.