Abstract: A method for transmitting a bidirectional packet flow between two nodes of a communication network. One of the nodes transmits to the other node one initial single marked packet of the bidirectional packet flow. Each one of the nodes transmits to the other node unmarked packets, until one single marked packet is received from the other node. In response thereto, each node transmits to the other node one single marked packet of the bidirectional packet flow. This mechanism is continuously performed by the nodes, thereby causing the nodes to cyclically exchange single marked packets of the bidirectional packet flow. A measurement point placed on the path of the bidirectional packet flow may then detect the single marked packets transmitted in a certain direction and provide RTT measurements based on differences between their detection times.

Abstract: It is disclosed a method for performing a RTT measurement on a bidirectional packet flow transmitted between two nodes of a packet-switched communication network. Each node applies a respective marking value to its outgoing packets, and switches outgoing packet does not exceed a predefined time threshold. An intermediate measurement point may provide an RTT measurement as a time lapsing between two consecutive switching of the marking value in the packets transmitted in a certain direction.

Abstract: A method for monitoring packets in a communication network includes at an ingress point, classifying at least one packet of a traffic received at the ingress point for determining whether packets of the traffic are to be monitored and, in the affirmative, associating them with a service of monitoring; at the ingress point, creating a selection policy to identify a packet flow of the packets to be monitored according to the service of monitoring. The method also includes installing the selection policy at one or more measuring points within the communication network, and at each measuring point, identifying the packet flow on the basis of the selection policy. The method further includes at each measuring point, applying monitoring actions associated with the service of monitoring to the identified packet flow.

Abstract: A method for providing one-way delay measurements on a bidirectional packet flow exchanged between two nodes of a packet-switched network. Each packet of the bidirectional packet flow comprises a marking field. At predefined times, the two nodes start transmission of respective measurement packet blocks made of packets with marking field set equal to a measurement value. Each node continues transmission of the respective measurement packet block, until it starts receiving the measurement packet block transmitted by the other node. In response thereto, each node ends transmission of the respective measurement packet block. A measurement point placed on the path of the bidirectional packet flow detects the measurement packet blocks and provides one-way delay measurements based on their time properties. For example, the end-to-end one-way delay in a given direction may be measured as the duration of the measurement packet block transmitted in the opposite direction.

Abstract: A method for performing a one-way delay measurement on a bidirectional packet flow carrying live traffic exchanged between two nodes of a packet-switched communication network. At predefined times, each node transmits to the other node a respective marked packet of the bidirectional packet flow. Each node then transmits unmarked packets of the bidirectional packet flow, until it receives the marked packet transmitted by the other node. In response thereto, each node transmits to the other node another marked packet of the bidirectional packet flow. A measurement point may be placed on the path of the bidirectional packet flow, for detecting the marked packets transmitted in either direction, and for providing a one-way delay measurement based on their detection times.

Abstract: A method for performing a performance measurement in a communication network. Each measurement point in the network identifies packets of a multipoint packet flow and selects therefrom a number of samples, based on the value of a sampling signature calculated by applying a hash function to a bit mask in each identified packet. For each sample, a performance parameter and the packet's content are provided to a management server. The management server identifies a cluster of measurement points such that each identified packet of the multipoint packet flow received by a cluster's input measurement point is also received at a cluster's output measurement point. Amongst the performance parameters provided by the cluster's measurement points, the performance parameters relating to samples belonging to a certain packet sub-flow are identified, based on the packet's content. Then, a performance measurement is performed on the packet sub-flow.

Abstract: It is disclosed a method and system for providing performance measurements in a packet-switched communication network, wherein a performance measurement application run by a user communication device monitors the performance of a packet flow which a user application run by the user communication device exchanges with the packet-switched communication network. This monitoring comprising providing values of a performance parameter relating to the packet flow. If, based on the performance parameter values provided by the performance measurement application, a failure condition affecting the packet flow is detected, a further monitoring of the performance of the packet flow is activated, by one or more measurement points located within the packet-switched communication network on the path of the packet flow. This further monitoring comprising providing values of a further performance parameter relating to the packet flow.

Abstract: It is disclosed a performance measurement application for a user communication device. The device runs at least one user application which exchanges at least one packet flow with a packet-switched communication network. When executed, the performance measurement application receives from an owner of the user communication device a request for performing a performance measurement. In response to such request, the performance measurement application activates a marking functionality comprising marking upstream packets of the packet flow to be measured and inducing the network node originating the downstream packets of the packet flow to be measured to mark them. The performance measurement application then provides performance parameter(s) relating to the marked upstream packets as transmitted and/or the marked downstream packets as received and, based on such parameter(s), provides a performance measurement. The measurement results are then shared with a measurement management server.

Abstract: It is disclosed a method for enabling a performance measurement in a packet-switched communication network. A first node and a second node exchange packets comprising a marking value, which they alternately switch between two alternative marking values. The second node in particular switches the marking value applicable to the packets addressed to the other node depending on the marking value comprised in packets received therefrom. The first node writes a sampling value in one packet addressed to the second node for each marking period. Upon reception of each packet comprising the sampling value, the second node copies the sampling value in a packet addressed to the first node. One or more measurement points may be provided between the two nodes, which provide performance parameters for the packets comprising the sampling value in both directions. Such performance parameters may be used for providing round trip time measurements.

Abstract: A method for exchanging packets between two nodes of a packet-switched communication network. Each packet comprises a marking field and a reflected marking field. Each node sets the value of the marking field in its outgoing packets to be transmitted to the other node. This value is alternately switched between two alternative marking values every N outgoing packets. While incoming packets are received from the other node, each node also sets the value of the reflected marking field of its outgoing packets according to the value of the marking field of the incoming packets. An observer placed between the two nodes may count the packets whose marking field is equal to any of the marking values and/or the packets whose reflected marking field is equal to any of the marking values, and use N and such counts to provide a packet loss measurement.

Abstract: A method for enabling a performance measurement on packet flow transmitted through a communication network. A marking value is periodically switched in the packets with a marking period Tm. The packet flow is then divided into blocks of duration Ts (synchronization period). Each synchronization period comprises an integer number of marking periods. Two or more measurement points on the path of the packet flow may provide a performance parameter for each marking period and associate thereto a synchronization information generated based on their local clocks and relating to the synchronization period containing the marking period to which the performance parameter relates; and a sequence information indicating the marking period's position within the synchronization period. A management server may identify performance parameters provided by different measurement points and relating to a same marking period based on the synchronization information and the sequence information.

Abstract: An apparatus and associated method for processing packets transmitted in a packet-switched communication network includes a sampling module that identifies amongst the received packets a plurality of samples distributed in a statistically uniform way amongst at least two non-overlapping sample sequences. Each sample sequence is then subjected to at least one identification rule, thereby identifying in the sample sequence at least one sub-sequence of samples fulfilling the at least one identification rule. The identification rule comprises a condition on the value of at least one identification field of the packets. Then, at least one parameter indicative of a behavior of the at least one sub-sequence of samples is provided.

Abstract: In a method for exchanging packets between first and second nodes of a packet-switched network, each packet comprises two fields settable to an idle value or measurement value. The first node transmits to the second node first packets having a filed set to measurement value. Upon reception of each first packet, the second node transmits back to the first node a second packet having a field set to measurement value. Upon reception of each second packet, the first node transmits to the second node a third packet having another field set to measurement value. A packet loss measurement is calculated as a difference between the number of first packets and the number of third packets.

Abstract: A method for enabling a round-trip packet loss measurement in a packet-switched communication network wherein a first node and a second node exchange packets comprising a packet loss field settable to an idle value or one or more measurement values. The first node performs a generation step whereby first packets having their set to a measurement value are transmitted to the second node. For each received first packet, the second node transmits back a second packet having its set to a measurement value. The first node then performs a reflection step whereby, for each received second packet, it transmits to the second node a respective third packet having its set to a measurement value. The time lapsing between start of the generation step and start of the reflection step has a predefined and substantially constant duration.

Abstract: A method for enabling a round-trip packet loss measurement between two nodes of a packet-switched communication network exchanging packets comprising a packet loss field settable to an idle value or one or more measurement values. The first node transmits to the second node first packets having the packet loss field set to a measurement value. Upon reception of each first packet, the second node transmits back to the first node a respective second packet having the packet loss field set to a measurement value. Upon reception of each second packet, the first node transmits back to the second node a respective third packet having the packet loss field set to a measurement value. A measurement point placed between the two nodes may count the number of first packets and the number of third packets and use them to provide a round-trip packet loss measurement.

Abstract: A method and system for statistically tracking the dynamics of a population over an area comprising entry points and exit points such that each population member entering through one entry point either exits through one exit point or stations within the area. At each entry point, an entry counter counts the number of entering members and, at each exit point, an exit counter counts the number of exiting members. Based on the counter values, the dynamics of the population are statistically tracked in terms of evolution in time of the number of members stationing in the area. The number of stationing members is retroactively adjusted when during an observation period it is determined that the number of exiting members is higher than the number of entering members, plus the number of members which were stationing within the area at the beginning of the observation period.

Abstract: A method is provided for transmitting encrypted packets from a first node to a second node of a communication network. The first node pads each plaintext packet with a respective padding content. The padded plaintext packets are then encrypted and transmitted to the second node. For each plaintext packet, the first node randomly selects the padding size in a range comprised between a minimum padding size and a maximum padding size. If the size of a plaintext packet is lower than a predefined minimum packet size, the minimum padding size is set equal to the difference between predefined minimum packet size and the plaintext packet size.

Abstract: A method for performing a performance measurement in a communication network. Each measurement point in the network identifies packets of a multipoint packet flow and selects therefrom a number of samples, based on the value of a sampling signature calculated by applying a hash function to a bit mask in each identified packet. For each sample, a performance parameter and the packet's content are provided to a management server. The management server identifies a cluster of measurement points such that each identified packet of the multipoint packet flow received by a cluster's input measurement point is also received at a cluster's output measurement point. Amongst the performance parameters provided by the cluster's measurement points, the performance parameters relating to samples belonging to a certain packet sub-flow are identified, based on the packet's content. Then, a performance measurement is performed on the packet sub-flow.

Abstract: A method for performing a performance measurement on a multipoint packet flow transmitted in a packet-switched subnetwork. A monitoring network of measurement points is implemented in the subnetwork. All packets have a marking value, which is periodically switched between first and second marking values. Each measurement point receiving a marked packet updates a couple of performance parameters, one per each marking value. Since not all the measurement points receive the same packets of the multipoint packet flow, to provide a performance measurement a cluster of measurement points is firstly identified in the monitoring network, which possesses the following property: each packet received at the input of the cluster is also received at the output of the cluster, if no packet loss occurs. The performance parameters provided by input and output measurement points of the identified cluster are then used for providing the performance measurements.

Abstract: A method for enabling a performance measurement on packet flow transmitted through a communication network. A marking value is periodically switched in the packets with a marking period Tm. The packet flow is then divided into blocks of duration Ts (synchronization period). Each synchronization period comprises an integer number of marking periods. Two or more measurement points on the path of the packet flow may provide a performance parameter for each marking period and associate thereto a synchronization information generated based on their local clocks and relating to the synchronization period containing the marking period to which the performance parameter relates; and a sequence information indicating the marking period's position within the synchronization period. A management server may identify performance parameters provided by different measurement points and relating to a same marking period based on the synchronization information and the sequence information.