Packet Loss Measurement Based on Sampled Flow

This paper is devoted to further strengthening, in the current asymmetric information environment, the informed level of operators about network performance. Specifically, in view of the burst and perishability of a packet loss event, to better meet the real-time requirements of current high-speed backbone performance monitoring, a model for Packet Loss Measurement at the access network boundary Based on Sampled Flow (PLMBSF) is presented in this paper under the premise of both cost and real-time. The model overcomes problems such as the inability of previous estimation to distinguish between packet losses before and after the monitoring point, deployment difficulties and cooperative operation consistency. Drawing support from the Mathis equation and regression analysis, the measurement for packet losses before and after the monitoring point can be realized when using only the sampled flows generated by the access network boundary equipment. The comparison results with the trace-based passive packet loss measurement show that although the proposed model is easily affected by factors such as flow length, loss rate, sampling rate, the overall accuracy is still within the acceptable range. In addition, the proposed model PLMBSF, compared with the trace-based loss measurement is only different in the input data granularity. Therefore, PLMBSF and its advantages are also applicable to aggregated traffic.

SDN-Empowered Reliable and Dynamic Scheduling Scheme for Security Resources

By endowing network with the ability of reliable scheduling of security resources, it can realize the dynamic deployment of security resources as well as the efficient configuration of protection resources, and further can quickly respond to network security threats and emergencies timely. Furthermore, due to the network is increasingly complex, it is of great importance to make it reliable by invoking appropriate security resources. However, the security mechanism and response speed of traditional network based on security domain division, network boundary protection are hard to meet the requirements of the virtual network. In this paper, we propose the SDN-empowered reliable and dynamic scheduling scheme for security resources. In the scheme, we use network security resource virtualization technology to virtualize and modularize network security software and hardware resources; at the SDN control layer, we propose meta-security function combination technology to provide on-demand customization for various security applications’ security service; by using role-based conflict detection and conflict resolution technology, we can detect and handle security rule conflicts. The experiments show that the scheme is reliable and efficient with low latency and great throughput.

Deep Packet Filtering Mechanism for Secure Internetworks

In this paper, we propose a Deep Packet Filtering Mechanism (DPFM) to analyze and filter malicious data packets moving between network environments. DPFM analyzes the behavior of malicious packets on the network and extracts information about the network as a sequence. After performing the word embedding process on the extracted sequence data using the word2vec technique, it detects malicious packets on the network by learning the LSTM model. In the past, research on filters to prevent malicious packets from entering the network by converting packets into data at the sending and receiving destinations and analyzing their purpose and maliciousness is insufficient. Since DPFM proceeds at the network boundary to analyze and extract malicious packets, primary detection is possible. In this paper, more accurate identification is possible by deep learning of network packets as well as OPcode and system calls, which are static analysis data.

Transdisciplinarity and Shifting Network Boundaries: The Challenges of Studying an Evolving Stakeholder Network in Participatory Settings

Participatory research engages a transdisciplinary team of stakeholders in all aspects of the research process. Such engagement can lead to shifts in the research design, as well as who is considered a participant. We detail our experiences of studying an evolving stakeholder network in the context of a 2.5-year transdisciplinary, participatory project. We show how participation leads to shifts in the network boundary overtime and how a transdisciplinary effort was needed to retrospectively redefine the network boundary. Through tacking back and forth between ethnographic insights, research aims, and modeling assumptions, the team eventually reached agreement on what determined network membership and how to code network members according to their timing and level of participation. Our account advances literature on boundary and modeling approaches to shifting, evolving networks by demonstrating how participatory transdisciplinarity can be both a driver of, and solution to, capturing the complexity of evolving networks.

Investigation of MAC Algorithms for Cross-Boundary Exchange between Wireless Sensor Networks

Increasing deployments of wireless sensor networks (WSNs), following the trend of the Internet of Thing (IoT), heightens the probability of the spatial overlap between WSNs in the same local area. The direct communication between distinctive networks can be supported by the direct interconnection between sensor nodes in any possible intersecting area. The packet transfer between the neighbouring networks offers multiple benefits by sharing data or network resources. However, the communication protocol adopted by each WSN can be different due to its conditions design and preferences preventing transmission and reception of packets from other network domains. One of the possible solutions for the compatibility problem is using a lightweight communication protocol for communication across the boundary while allowing networks to use its preferred communication stack inside its domain. This work investigates the MAC algorithm used for communication across the network boundary. The synchronous/asynchronous duty cycle MAC algorithm is practically evaluated by using a testbed. The experiment results suggest using the synchronous duty cycle protocol for communication across the network boundary consumes less energy offers improved latency and reliability than the previously proposed asynchronous duty cycle protocol.

Application Research of File Fingerprint Identification Detection Based on a Network Security Protection System

A DLP (data loss prevention) system usually arranges network monitors at the network boundary to perform network traffic capture, file parsing, and strategy matching procedures. Strategy matching is a key process to prevent corporate secret-related documents from leaking. This paper adopts the document fingerprint similarity detection method based on the SimHash principle and customizes the KbS (Keyword-based SimHash) fingerprint, PbS (Paragraph-based SimHash) fingerprint, and SoP (SimHash of Paragraph) fingerprint, three different feature extraction SimHash algorithms for strategy matching to detect. The parsed unstructured data is stored as a file type in.txt format, and then a file fingerprint is generated. Matching the established sensitive document library to calculate the Hamming distance between the fingerprints, the Hamming distance values under different modification degrees are summarized. The experimental results reveal that the hybrid algorithmic strategy matching rules with different levels and accuracy are established. This paper has a reference role for the leakage prevention research of enterprise sensitive data.

The network boundary specification problem in the global and world city research: investigation of the reliability of empirical results from sampled networks

Despite the well-known dependence of vertex and network structural parameters on network boundary specification employed by researchers, there has so far been effectively no discussion of this methodological caveat in the global and world city literature. Given the reliance of empirical studies of urban networks on the sampling of underlying actors that form these networks by their interactions, we consider it of key importance to examine the dependence of network centralities of cities on network boundary specification. We consider three distinctive modelling approaches based on: (a) office networks, (b) ownership ties and (c) inter-organisational projects. Our results indicate that city network centralities obtained from sampled networks are highly consistent with those obtained from whole network analysis for samples featuring as little as 4% (office networks), 10% (ownership ties) and 25% (inter-organisational projects) of the underlying actors.

Investigating preferential flow dynamics in idealized porous fracture networks via (quasi) 2-D lab experiments – Controls of fracture and matrix properties on flow behavior

<p>Quantification of infiltration processes in the vadose zone of fractured-porous media and karst systems (epikarst), especially onset and magnitude of preferential flow, as well as the interaction between fast (fractures, macropores) and slow pathways (matrix), is still lacking a sound conceptualization.</p><p>This study presents results from laboratory experiments which were designed to delineate the control of network topology, fracture aperture, matrix imbibition and infiltration conditions on preferential flow dynamics. We create vertical 2-D fracture networks using a set of equally sized (Seeberger) sandstone blocks placed in between two transparent glass plates. Blocks are arranged to create an orthogonal network with vertical and horizontal fractures of constant aperture. Water is injected with a constant rate directly into the middle vertical fracture on the upper network boundary by a pump. Mass flux across the lower network boundary is measured by a scale to register first arrival. In addition, flow partitioning at intersections and advance of the wetting front were visually captured.</p><p>Two experiment series were carried out: (1) the effect of horizontal offset (2, 5, 10, 15, 20 and 24 mm) was studied for two different fracture apertures (1 and 3 mm), but constant infiltration rate (1.5 ml/min). (2) The fracture aperture was kept constant (1 mm) and infiltration rate was varied (0.75, 1.50 and 3.00 ml/min), as well as the offset. The first series demonstrates that greater offset is associated with pathway spreading and hence divergent behavior of the wetting front, as well as later arrival times. Pathway spreading increases the fracture-matrix interface area in total, thus preferential flow is slowed down more efficiently by the imbibition process. Less pathway spreading, and faster arrival times were observed for the larger aperture configuration (3 mm). Aperture (and infiltration rate) strongly controls flow modes. Whereas slug flow (liquid in contact with both fracture walls) is a dominant flow mode in the 1 mm aperture configuration due to capillary forces, it is not the prevailing mode in the 3 mm aperture configuration. The second series reveals faster arrival times for higher inflow rates (3.00 > 1.50 > 0.75 ml/min), as well as smaller differences between arrival times of different offsets as flow rate increases. </p><p>To capture bulk infiltration dynamics, the results can help to parameterize analytical infiltration models such as the source-responsive dual domain model, which was developed by Nimmo (2010, VADOSE ZONE J) to capture preferential flow dynamics in soils.</p>