A method is disclosed for the collection of performance metrics by establishing service operations administration and maintenance (OAM) sessions between an actuator and a plurality of reflectors in a communication network. Test packets from an actuator simultaneously reach a plurality of reflectors along a test path. Each single test packet results into a plurality of test results, one per reflector, with quasi-synchronous performance metrics to sectionalize a network and more efficiently isolate fault or performance problems without the need for additional test packets to isolate the issue. Another method is disclosed wherein an actuator generates and transmits a plurality of simultaneous test packets, one per NID device, resulting into a plurality of test results, one per reflector, with quasi-synchronous performance metrics to sectionalize a network and more efficiently isolate fault or performance problems without the need for additional test packets to isolate the issue.

An information terminal sequentially transmits one or more packets to an information distribution server, receives acknowledgments for the transmitted packets from the information distribution server, and records a round trip time and occurrence of packet loss for each of the transmitted packets. Among one or more packet sequences, the information terminal counts the number of packet sequences which are such that the number of packet losses included in each of the packet sequences and an increase state of the round trip time for packets included in the packet sequence satisfy respective predetermined conditions. Each of the one or more packet sequences has multiple continuous packets including one or more packets, for which packet loss is recorded among the transmitted packets, at the top. The information terminal calculates a packet loss ratio on the basis of the counted number and the number of transmitted packets.

Various embodiments of a network element comprising a control plane including stream tracer logic are described herein. The network element additionally includes a data plane coupled to the control plane, where the data plane includes forwarding logic to forward a unit of network data from an ingress interface to an egress interface. The stream tracer logic can be configured to cause marking logic to mark selected units of network data for to be counted by counting logic and to cause the counting logic to count marked units of network data. The stream tracer logic can determine whether units of network data are dropped within the forwarding logic via comparison of an ingress count of the marked units of network data with an egress count of the marked units of network data.

Hence a method is provided for determining a quality value of a video stream, comprising the steps of: identifying lost data packets of the video stream; identifying at least two intra coded frames of the video stream; determining intra coded frames having a maintained image quality, based on estimating if a lost data packet is associated with an intra coded frame; estimating a distance between each one of the lost data packets and a next respective, subsequent intra coded frame having a maintained image quality; and generating the quality value, based on the distances. A system and a computer readable medium are also described.

A computing system manages communications congestion by selecting a transmission rate differently in different operating modes. In a delay-plus-loss mode, the transmission rate is selected as the lesser of a rate that would be selected by loss-based algorithm or by a delay-based algorithm. In a loss-based mode, the transmission rate is selected as the lesser of a rate that would be selected by loss-based algorithm, on one hand, and the maximum of a rate that would be selected by a delay-based algorithm or a rate proportional to the maximum estimated link rate divided by the number of data flows estimated to be competing for link bandwidth on the other hand. A database may be maintained of observations of network and link performance over time, where the database contains such information as the maximum estimated link rate capacity, minimum delays, and minimum losses.

Embodiments of the present disclosure disclose a data transmission method and apparatus, and belong to the field of Internet technologies. The method includes: obtaining interaction information of a transmission link of a current moment; analyzing the interaction information, to obtain link status information corresponding to the interaction information; determining an available bandwidth for current data transmission according to the link status information that corresponds to the interaction information and link status information that corresponds to historical interaction information of the transmission link; and transmitting a data packet to a data receive end according to the available bandwidth. In the embodiments of the present disclosure, data transmission is performed based on the TCP Protocol, neither a data receive end nor a data transmit end needs to support an additional protocol, and applicability is relatively strong.

The present disclosure relates to an unmanned aerial vehicle (UAV), a terrestrial station thereof and a data transmission method. A data transmission method is applied to a terrestrial station and the method includes: receiving data packets continuously sent by a UAV; detecting continuity of data packet sequence numbers of the received data packets; and sending a data packet retransmission request to the UAV according to a lost data packet sequence number if it is detected that the data packet sequence numbers corresponding to the data packets are discontinuous. Adopting the UAV, the terrestrial station and the data transmission method that are provided in the present disclosure can effectively improve utilization of an uplink transmission link.

Embodiments of this disclosure provide a method and apparatus for evaluating node performance and a system. The method includes: real-time communication related information of a network node is collected; normalization on the test data within the predetermined period of time is performed by using preobtained best data vectors and worst data vectors, so as to obtain normalized multi-dimensional vectors of the test data within the period of time; and the normalized multi-dimensional vectors of the test data within the period of time is weighted, distance from the weighted normalized multi-dimensional vectors to the best data vectors is calculated, and a grade of the network node is determined according to the distance and a predefined monotonically decreasing function. With the embodiments of this disclosure, by collecting real-time communication related information of a network node in a wireless network, performing statistical analysis on the collected information, and performing node performance evaluation by using a method for comparing the training data and the test data, thereby providing references for network service providers in performing network optimization.

In one implementation, performance statistics for a provider network are compiled and delivered outside of the provider network. The provider network includes a media trace proxy server that receives a media trace query for a media stream of a customer edge network device. The media trace proxy server initiates a route discovery process on the provider network in response to the request or in response to at least one network device in the provider network being nonresponsive to similar types of media trace queries. The media trace proxy server collects performance statistics from the at least one network device and forwards the performance statistics of the at least one network device to the customer edge network device. The performance statistics may include only those statistics authorized by a subscription level or administrative region of the customer edge network device.

Mechanisms for devolving microflows from aggregate flows are disclosed. An ingress node receives a packet that matches an aggregate flow entry in a flow table. A determination that a devolve action is associated with the aggregate flow entry is made. Based on the determination that the devolve action is associated with the aggregate flow entry, a microflow flow entry is generated in the flow table to define a microflow. The microflow flow entry includes header information extracted from the packet. Microflow generation information that identifies the microflow is sent to a controller node. It is determined that the microflow has timed out based on an idle timeout period of time. In response to determining that the microflow has timed out, microflow termination information that includes path measurement metric information associated with the microflow is sent to the controller node.