Abstract: It is disclosed a method for performing a performance measurement on a packet flow transmitted through a packet-switched communication network. In the packet flow, first blocks of packets having a first packet feature and second blocks of packets having a second packet feature are provided by periodically switching a packet feature in the packet flow, so that the first blocks of packets alternate in time with the second blocks of packets. Two or more measurement points on the path of the packet flow provide performance parameters relating to the first and second blocks of packets, and alternately provide their values to a network controller, which the controller uses to perform the performance measurement. The periodic switching of the packet feature and the alternate provision of the performance parameter values are in response to remote commands received from the controller.

Abstract: A method is disclosed for performing a performance measurement on a packet flow transmitted along a path through a packet switched communication network. At least two measurement points implemented on the path calculate a sampling signature for each packet of the flow by applying a hash function to a mask of bits of the packet, and identify a sub-flow of measurement samples as those packets whose sampling signatures are equal to a certain value H*. The measurement points then provide measurement parameters for the measurement samples, which are used for providing performance measurement for the whole packet flow. Tailoring the length of the sampling signature allows the sampling rate to be statistically controlled so as to balance the risk of reception sequence errors between measurement samples and the computational effort on one hand, and the accuracy of the measurements provided on the other hand.

Abstract: In a method for measurement of a round-trip performance in a packet-switched communication network, a measurement device cooperating with the communication network generates a flow of test packets formatted according to the network protocol supported by the network and comprising the address of the measurement device as destination address. The test packets are then transmitted within a tunnel set up in the network and the measurement device generates one or more transmission parameters. At the end of the tunnel, the test packets are extracted therefrom and sent back to the measurement device by the forwarding function of the network protocol supported by the network. Upon receipt of the test packets, it generates one or more reception parameters, which are then combined with the transmission parameters to provide the round-trip performance measurement.

Abstract: A method is disclosed for performing a performance measurement on a packet flow transmitted along a path through a packet switched communication network. At least two measurement points implemented on the path calculate a sampling signature for each packet of the flow by applying a hash function to a mask of bits of the packet, and identify a sub-flow of measurement samples as those packets whose sampling signatures are equal to a certain value H*. The measurement points then provide measurement parameters for the measurement samples, which are used for providing performance measurement for the whole packet flow. Tailoring the length of the sampling signature allows the sampling rate to be statistically controlled so as to balance the risk of reception sequence errors between measurement samples and the computational effort on one hand, and the accuracy of the measurements provided on the other hand.

Abstract: A system for fault and performance recovery in a communication network includes a set of network apparatuses as well as a plurality of sites connected by means of connections having a given topology. The network also includes routers for implementing given routing policies and has associated therewith at least one database maintaining information regarding the network apparatuses. The system includes test modules for executing performance tests created automatically by exploiting the information available on the topology of the connections between the various sites and by accessing the database in question. The test modules are configured for analysing the results of the performance tests to detect possible fault and performance impairment conditions of the network. In the presence of a fault and performance impairment condition detected in the network, the routers modify the routing policy to compensate for the fault and performance impairment condition.

Abstract: A system for fault and performance recovery in a communication network includes a set of network apparatuses as well as a plurality of sites connected by means of connections having a given topology. The network also includes routers for implementing given routing policies and has associated therewith at least one database maintaining information regarding the network apparatuses. The system includes test modules for executing performance tests created automatically by exploiting the information available on the topology of the connections between the various sites and by accessing the database in question. The test modules are configured for analysing the results of the performance tests to detect possible fault and performance impairment conditions of the network. In the presence of a fault and performance impairment condition detected in the network, the routers modify the routing policy to compensate for the fault and performance impairment condition.