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Internet of Medical Thing (IoMT) is an emerging technology in healthcare that can be used to realize a wide variety of medical applications. It improves people's quality of life and makes it easier to care for the sick individuals in an efficient and safe manner. To do this, IoMT leverages the capabilities of some new technologies including IoT, Artificial Intelligence, cloud computing, computer networks and medicine. Combining these technologies to monitor the patient's health conditions in real-time or semi-real-time is a critical challenge in IoMT. In this regard, one of the most crucial components of IoMT are network communication protocols that should provide a fast and reliable communication path between a connected biosensor to a patient and cloud computing environment. In this paper, we propose EQRSRL as an efficient routing mechanism for different types of IoMT applications. The aim of EQRSRL is to provide a reasonable level of Quality of Service (QoS) for IoMT traffics. To achieve this goal, it categorizes the network traffic into three classes and treats them differently concerning their QoS requirements. Moreover, EQRSRL divides the network environment into multiple zones to decrease the number of message exchange between the nodes. In order to compute optimal paths between the nodes, it considers QoS and energy metrics, and makes use of a reinforcement learning approach in path computation process. Simulation results show that the implementation of EQRSRL in IoMT is practical and leads to improvement of 82% in average energy consumption, 25% in end-to-end delay and 7% packet delivery ration in compared to the state-of-the-art routing techniques. [ABSTRACT FROM AUTHOR]

One of the key challenges in computer networks is network security. For securing the network, various solutions have been proposed, including network security protocols and firewalls. In the case of so-called packet-filtering firewalls, policy rules are implemented to monitor changes to the network and preserve the required security level. Due to the dramatic increase of devices, however, and herewith the rapid increase of the size of the policy rules, firewall policy anomalies occur more frequently. This requires careful implementation of the policy rules to ensure cost-efficient solutions for anomaly detection to support network security. In this study, we present an anomaly detection framework for detecting intrafirewall policy anomaly rules. The framework supports the simulation of packets through the firewall ruleset for validating and enhancing the security level of the network. The framework is validated using four different types of firewall policy anomalies. Experimental results demonstrate that the framework is effective and efficient in detecting firewall policy anomalies. [ABSTRACT FROM AUTHOR]

In today's world, the growth of computer networks is exponential as networking is an essential part of the latest technologies like Internet of Things (IoT), cloud computing, edge computing, etc., with the adoption of new technologies; security has become an important issue for such techniques. These networks need to be saved from a wide range of available attacks. In the literature, many intrusion detection systems (IDS) are used to detect such attacks. IDS can be signature based or anomaly based. The signature-based method can only detect a well-known attack while anomaly-based methods can detect new attacks but suffers from low performance. IDS with a potential anomaly detection mechanism to improve the performance is highly desirable. For the reasons mentioned above, this paper proposed an anomaly-based IDS with novel hybrid ensemble classification method based on grouping of the network traffic. The groups are created based on the services or protocol used by the network traffic. After grouping of network traffic, wrapper-based sequential feature selection (SFS) with random forest (RF) classifier is used to select optimal features and perform classification in each group. Furthermore, to validate the performance of the proposed model for service-based and protocol-based grouping approach, UNSW-NB15 and NSL-KDD datasets are used, respectively. The result shows that the proposed approach outperforms the existing feature selection approaches with high accuracy, precision, and F-score for both the datasets. [ABSTRACT FROM AUTHOR]

In the networks, a transport layer is responsible for reliable data with guaranteed Quality of Service. A Modified‐QUIC protocol provides improved throughput and reduced latency of the network. This work proposes a modification in handshaking mechanism for QUIC protocol to minimize overhead due to control signals and time required to update the congestion‐window size. This modification fine‐tunes the window update mechanism with the acknowledgment frame, which results in a smooth variation in the congestion‐window size. This leads to the control congestion by regulating traffic in the network. In the proposed mechanism, unnecessary time out events are avoided by updating the congestion‐window on receipt of the acknowledgment frame. This work has been carried out using two different testbed setups to verify the transport layer and a browser network performance. It has been observed that a Modified‐QUIC protocol is easy to deploy, improves the throughput and data rate by 35% and 3.43%, respectively, over the QUIC protocol. The average fairness index is increased with a file size and for the long live traffic. [ABSTRACT FROM AUTHOR]

Recent trends in high-performance computing and deep learning have led to the proliferation of studies on large-scale deep neural network training. However, the frequent communication requirements among computation nodes drastically slow the overall training speeds, which causes bottlenecks in distributed training, particularly in clusters with limited network bandwidths. To mitigate the drawbacks of distributed communications, researchers have proposed various optimization strategies. In this paper, we provide a comprehensive survey of communication strategies from both an algorithm viewpoint and a computer network perspective. Algorithm optimizations focus on reducing the communication volumes used in distributed training, while network optimizations focus on accelerating the communications between distributed devices. At the algorithm level, we describe how to reduce the number of communication rounds and transmitted bits per round. In addition, we elucidate how to overlap computation and communication. At the network level, we discuss the effects caused by network infrastructures, including logical communication schemes and network protocols. Finally, we extrapolate the potential future challenges and new research directions to accelerate communications for distributed deep neural network training. • Introduction of common techniques and schemes in distributed deep learning. • A comprehensive survey of communication optimization for distributed deep neural network training from algorithm and network perspective. • Putting forward several challenges and opportunities for communication optimization of distributed deep learning. [ABSTRACT FROM AUTHOR]

The paper discusses the problem of video transmission in an IP network. The authors consider the ability of using the most popular video codecs that use both the MPEG2 Transport Stream and Dynamic Adaptive Streaming over Hypertext Transfer Protocol (DASH). The main emphasis was given to ensuring the quality of service and quality assessment methods, taking into account not only the service- or network provider's point of view but also the end user's perspective. Two quality assessment approaches were presented, i.e. objective and subjective methods. The authors presented the results of the quality evaluation for H.264/MPEG-4, H.265/HEVC and VP9 codecs. The objective measurements, proved by statistical analysis of user opinion scores, confirmed the ability of using H.265 and VP9 codecs in both real time and streaming transmissions, while the quality of video streaming over HTTP with the H.264 codec proved inadequate. The authors also presented a connection between the dynamics of network bandwidth changing and MPEG-DASH mechanism operation and their influence on the quality experienced by users [ABSTRACT FROM AUTHOR]

Traffic classification in computer networks has very significant roles in network operation, management, and security. Examples include controlling the flow of information, allocating resources effectively, provisioning quality of service, detecting intrusions, and blocking malicious and unauthorized access. This problem has attracted a growing attention over years and a number of techniques have been proposed ranging from traditional port-based and payload inspection of TCP/IP packets to supervised, unsupervised, and semi-supervised machine learning paradigms. With the increasing complexity of network environments and support for emerging mobility services and applications, more robust and accurate techniques need to be investigated. In this paper, we propose a new supervised hybrid machine-learning approach for ubiquitous traffic classification based on multicriteria fuzzy decision trees with attribute selection. Moreover, our approach can handle well the imbalanced datasets and zero-day applications (i.e., those without previously known traffic patterns). Evaluating the proposed methodology on several benchmark real-world traffic datasets of different nature demonstrated its capability to effectively discriminate a variety of traffic patterns, anomalies, and protocols for unencrypted and encrypted traffic flows. Comparing with other methods, the performance of the proposed methodology showed remarkably better classification accuracy. [ABSTRACT FROM AUTHOR]

With the development and universal application of satellite technology, an important way to expand the function of satellites is setting up inter-satellite networks to make them work together. Traditional satellite networking methods generally adopt a fixed time slot allocation method, which is not suitable for small satellite groups with low latency and high throughput requirements. In order to solve this problem, it has been proposed to apply the traditional Wifi protocol in satellite networking. As there are differences between satellite networks and terrestrial networks, it’s necessary to improve the traditional 802.11 protocol. The Media Access Control (MAC) protocol in 802.11 is improved in this paper, which mainly includes the adaptive algorithm of maximum contention window size and the growth algorithm of Contention Window (CW) size. The maximum contention window is adjusted according to the conflict state of the current network, which makes the network accommodate more satellite nodes. The CW growth algorithm improves the traditional Binary Exponential Back-off (BEB) algorithm, where the CW is designed according to the priority of the data frame or the network load. In this way, high-priority satellite accusation information will have higher reliability or tolerate greater network load. [ABSTRACT FROM AUTHOR]

The computer network security evaluation simulation model is analyzed based on neural network. Firstly, based on the system security experimental platform, the system security detection algorithm is constructed, and the selection strategy of calculation scale is analyzed. The Prefix Span algorithm is introduced, improving its algorithm. Data mining based on Prefix is carried out, with the relationship between intrusions and their relationships analyzed. Secondly, the implementation steps of the algorithm are explained. Finally, the algorithm is tested, and the results are analyzed from three aspects: entropy value feature, active entropy algorithm and cloud platform performance. The conclusion is that the algorithm designed in this paper has good accuracy and adaptability, and it can play a good supporting role in system safety practice training, and the encryption protocol in the network security protocol is further improved, which has laid a solid foundation for the security development of the network. [ABSTRACT FROM AUTHOR]

Blockchain -- a distributed and public database of transactions -- has become a platform for decentralized applications. Despite its increasing popularity, blockchain technology faces a scalability problem: the throughput does not scale with the increasing network size. Thus, in this paper, we propose a scalable blockchain protocol to solve the scalability problem. The proposed method was designed based on a proof of stake (PoS) consensus protocol and a sharding protocol. Instead of transactions being processed by the whole network, the sharding protocol is employed to divide unconfirmed transactions into transaction shards and to divide the network into network shards. The network shards process the transaction shards in parallel to produce middle blocks. Middle blocks are then combined into a final BLOCK in a timestamp recorded on the blockchain. Experiments were performed in a simulation network consisting of 100 Amazon EC2 instances. The latency of the proposed method was approximately 27 s and the maximum throughput achieved was 36 transactions per second for a network containing 100 nodes. The results of the experiments indicate that the throughput of the proposed protocol increases with the network size. This confirms the scalability of the proposed protocol. [ABSTRACT FROM AUTHOR]

The issue of antenna correlation in multi-pair massive antenna relay network is studied. Under the spatial correlation properties of the channel, an analytical approximation for both upper and lower bounds using popular maximum ratio combining/maximum ratio transmission relaying scheme is developed. This gives an insight of the system achievable rate by exploiting channel reciprocity in the time-division duplex protocol. To this aim five special antenna correlation cases are discussed and the corresponding overall spectral efficiency is analyzed. The performance of the scheme is compared against the other precoding and receiver combining schemes, i.e., zero forcing and minimum-mean-squared-error processing under the antenna correlation model. The analytical results backed up by simulations clearly quantify the impacts of antenna correlation under various cases on user spectral efficiency. [ABSTRACT FROM AUTHOR]

This paper proposes an enhanced Fully Informed Communication-Induced Checkpointing (FI-CIC) protocol to highly improve the possibility of detecting Z-cycle free patterns with no extra control message by utilizing the advantageous feature of the broadcast network in an effective way compared with the original FI-CIC protocol. Experimental results show that our protocol outperforms the previous one in terms of the number of forced checkpoints per process. [ABSTRACT FROM AUTHOR]

One of the most important research fields of network sciences is the robustness of networks. A recently answered important question was the following: Which network topologies are more resistant to random malfunctions and/or direct attacks? Nevertheless, until now, “which system topology can be maintained and how to manage maintenance more efficiently and effectively” have been open questions. However, these questions are the keys both to designing large-scale systems and to scheduling maintenance tasks. This paper proposes a new means to analyze the maintainability of a large system by combining two kinds of networks, i.e., the reliability diagram of the system (1) and the network of scheduled maintenance tasks (2). This paper shows how to assign maintenance task(s) to a system component to increase the reliability of the system. With the proposed method, the maintainability of large-scale systems can be analyzed. [ABSTRACT FROM AUTHOR]

Global Mobility Networks(GLOMONETs) in wireless communication permits the global roaming services that enable a user to leverage the mobile services in any foreign country. Technological growth in wireless communication is also accompanied by new security threats and challenges. A threat-proof authentication protocol in wireless communication may overcome the security flaws by allowing only legitimate users to access a particular service. Recently, Lee et al. found Mun et al. scheme vulnerable to different attacks and proposed an advanced secure scheme to overcome the security flaws. However, this article points out that Lee et al. scheme lacks user anonymity, inefficient user authentication, vulnerable to replay and DoS attacks and Lack of local password verification. Furthermore, this article presents a more robust anonymous authentication scheme to handle the threats and challenges found in Lee et al.’s protocol. The proposed protocol is formally verified with an automated tool(ProVerif). The proposed protocol has superior efficiency in comparison to the existing protocols. [ABSTRACT FROM AUTHOR]

Network protocol vulnerability detection plays an important role in many domains, including protocol security analysis, application security, and network intrusion detection. In this study, by analyzing the general fuzzing method of network protocols, we propose a novel approach that combines network traffic analysis with the binary reverse engineering method. For network traffic analysis, the block-based protocol description language is introduced to construct test scripts, while the binary reverse engineering method employs the genetic algorithm with a fitness function designed to focus on code coverage. This combination leads to a substantial improvement in fuzz testing for network protocols. We build a prototype system and use it to test several real-world network protocol implementations. The experimental results show that the proposed approach detects vulnerabilities more efficiently and effectively than general fuzzing methods such as SPIKE. [ABSTRACT FROM AUTHOR]

Session types are used to describe communication protocols in distributed systems and, as usual in type theories, session subtyping characterizes substitutability of the communicating processes. We investigate the (un)decidability of subtyping for session types in asynchronously communicating systems. We first devise a core undecidable subtyping relation that is obtained by imposing limitations on the structure of types. Then, as a consequence of this initial undecidability result, we show that (differently from what stated or conjectured in the literature) the three notions of asynchronous subtyping defined so far for session types are all undecidable. Namely, we consider the asynchronous session subtyping by Mostrous and Yoshida for binary sessions, the relation by Chen et al. for binary sessions under the assumption that every message emitted is eventually consumed, and the one by Mostrous et al. for multiparty session types. Finally, by showing that two fragments of the core subtyping relation are decidable, we evince that further restrictions on the structure of types make our core subtyping relation decidable. [ABSTRACT FROM AUTHOR]

To improve the efficiency of carrier sense multiple access (CSMA)-based medium access control (MAC) protocol, CSMA with collision resolution (CSMA/CR) has been proposed. In the CSMA/CR protocol, a transmitting station can detect a collision by employing additional carrier sensing after the start of data transmission and resolve the next collision that might occur by broadcasting a jam signal during a collision detection (CD) period. By extending this original CSMA/CR protocol that uses a single CD phase, in this paper we propose a multi-phased CSMA/CR (MP-CSMA/CR) protocol that employs multiple CD phases. In the proposed MP-CSMA/CR protocol, colliding stations are filtered in each CD phase, and only surviving stations compete again in the next CD phase. Therefore, the collision resolution probability becomes higher as the CD phases proceed. Utilizing the multiple CD phases, we analyze the throughput numerically and find optimal operating parameters-such as the number of CD phases and the number of CD slots per phase-that maximize the throughput. Based on this result, we also propose a dynamic MP-CSMA/CR protocol in which the number of CD phases is dynamically changed to suit network conditions. Analysis and simulation results show that the proposed MP-CSMA/CR protocol significantly outperforms CSMA/CR with a single CD phase. The dynamic MP-CSMA/CR protocol achieves a slightly better throughput than MP-CSMA/CR, which uses a fixed optimal number of CD phases. [ABSTRACT FROM AUTHOR]

Mobile IP allows for location-independent routing of IP datagrams on the Internet. Mobile IP specifies how a mobile node (MN) registers with its home agent and how the home agent routes datagrams to the MN through the tunnel. Current Mobile IP protocols have difficulties meeting the stringent handover delay requirements of future wireless networks. Fast handover for Proxy Mobile IPv6 (FPMIPv6) is used to resolve handover latency and packet loss problems that occur in the Proxy Mobile IPv6 (PMIPv6) protocol. However, while implementing the FPMIPv6 scheme in a testbed, we encounter the out-of-order packet (OoOP) problem. The cause of this problem is the existence of two paths for data transmitted from a correspondent node (CN) to an MN. Since the problem affects the quality of service (QoS) of the network and the performance of the MN, we propose a new scheme using the last packet marker and packet buffering to solve this problem in FPMIPv6. The new Mobile Access Gateway (MAG) can control and deliver the data transmitted via the old path or the new path to an MN in order, using the last packet marker to notify the end of the data delivery in the old path and the packet buffering for holding the data delivered in the new path. We implement both the proposed scheme and FPMIPv6 in a testbed as a real network environment to demonstrate the correctness, cost effectiveness, and performance of the proposed scheme. A performance evaluation reveals that the proposed scheme can handle the OoOP problem efficiently. [ABSTRACT FROM AUTHOR]

In this paper, a secure cross-layer-based routing technique (SCLARDI) for a mobile ad hoc network (MANET) is proposed. This technique makes use of ad hoc on-demand routing protocol (AODV) algorithms and honey pot technology to detect and isolate black hole attacks from MANETs. This novel system is compared with the single-layer design techniques and existing cross-layer detection techniques. Out of the tested models, the proposed cross-layer design is the most suitable for MANET security. First, the vulnerabilities of the AODV routing protocol against black hole attacks are analyzed. Second, a secure cross-layer-based AODV routing technique is proposed. The proposed SCLARDI technique detects and isolates black hole attacks from MANET. Finally, the results are compared with the existing techniques. The simulations are done using NS-2. The simulation results show that the proposed technique improves the packet delivery ratio and reduces network overhead, normalized routing load, and packet drop ratio compared to other existing single-layer and cross-layer techniques. [ABSTRACT FROM AUTHOR]

OpenFlow currently is the only one protocol that can implement ideas of the Software Defined Networking pioneers. The Protocol is unique because of ability to separate any network device control and data planes. All network intelligence is (logically) centralized in dedicated controllers. Objective of this article to propose a new method that enhances QoS in data networks by using OpenFlow protocol. [ABSTRACT FROM AUTHOR]

Protocol Oblivious Forwarding (POF) aims at providing a standard southbound interface for sustainable Software Defined Networking (SDN) evolvement. It overcomes the limitations of popular OpenFlow protocols (an existing widely-adopted southbound interface), through the enhancement of SDN forwarding plane. This paper pioneers the design and implementation of a Kernel-space POF Virtual Switch (K_POFVS) on Linux platform. K_POFVS can improve the packet processing speed, through fast packet forwarding and the capability of adding/deleting/modifying protocol fields in kernel space. In addition, it is able to enhance flow table matching speed, by separating the mask table (consisting of flow entry masks used to figure out the matching field) and the flow table under a caching mechanism. Furthermore, K_POFVS can achieve efficient communication between the kernel space and the user space, via extending the netlink communication between them. Experimental results show that K_POFVS can provide much better performance than existing user-space POF virtual switches, in terms of packet forwarding delay, packet processing delay and packet transmission rate. [ABSTRACT FROM AUTHOR]

Wireless customers expect to have a guaranteed quality of experience at all times, at any location, and through different devices. Wi-Fi has become an access network of preference for service/ network providers and customers as well for public and private access. This sets a challenging requirement for next-generation Wi-Fi technology to provide seamless and uniform network quality of service). Consequently, the necessity for self-optimization of network and radio frequency segments becomes critical. This article surveys challenges and use cases of Wi-Fi self-optimizing networks (Wi-SONs) that have not been presented to date. We address technology and design challenges that shape Wi-SON as a very complex problem. [ABSTRACT FROM PUBLISHER]

The work, presented in this article, aims at performing scheduling analysis of Time Division Multiple Access (TDMA) based communication systems. Products called software radio protocols, developed at Thales Communications & Security, are used as case-studies. Such systems are real-time embedded systems. They are implemented by tasks that are statically allocated on multiple processors. A task may have an execution time, a deadline and a release time that depend on TDMA configuration. The tasks also have dependencies through precedence and shared resources. TDMA-based software radio protocols have architecture characteristics that are not handled by scheduling analysis methods of the literature. A consequence is that existing methods give either optimistic or pessimistic analysis results. We propose a task model called Dependent General Multiframe (DGMF) to capture the specificities of such a system for scheduling analysis. The DGMF task model describes, in particular, the different jobs of a task, and task dependencies. To analyze DGMF tasks, we propose their transformation to real-time transactions and we also propose a new schedulability test for such transactions. The general analysis method is implemented in a tool that can be used by software engineers and architects. Experimental results show that our propositions give less pessimistic schedulability results, compared to fundamental methods. The results are less pessimistic for both randomly generated systems and real case-studies from Thales. These results are important for engineering work, in order to limit the over-dimensioning of resources. Through tooling, we also automated the analysis. These are advantages for engineers in the more and more competitive market of software radios. [ABSTRACT FROM AUTHOR]

Edge-independent spanning trees (EISTs) have important applications in networks such as reliable communication protocols, one-to-all broadcasting, and secure message distribution, thus their designs in several classes of networks have been widely investigated. The n -dimensional augmented cube ( A Q n ) is an important variant of the n -dimensional hypercube. It is ( 2 n − 1 )-regular, ( 2 n − 1 )-connected ( n ≠ 3 ), vertex-symmetric and has diameter of ⌈ n / 2 ⌉ . In this paper, by proposing an O ( N log ⁡ N ) algorithm that constructs 2 n − 1 EISTs in A Q n , where N is the number of nodes in A Q n , we solve the EISTs problem for this class of graphs. Since A Q n is ( 2 n − 1 )-regular, the result is optimal with respect to the number of EISTs constructed. [ABSTRACT FROM AUTHOR]

Population protocols (Angluin et al. in PODC, 2004) are a formal model of sensor networks consisting of identical mobile devices. Two devices can interact and thereby change their states. Computations are infinite sequences of interactions satisfying a strong fairness constraint. A population protocol is well specified if for every initial configuration C of devices, and every computation starting at C, all devices eventually agree on a consensus value depending only on C. If a protocol is well specified, then it is said to compute the predicate that assigns to each initial configuration its consensus value. While the computational power of well-specified protocols has been extensively studied, the two basic verification problems remain open: Is a given protocol well specified? Does a given protocol compute a given predicate? We prove that both problems are decidable by reduction to the reachability problem of Petri nets. We also give a new proof of the fact that the predicates computed by well-defined protocols are those definable in Presburger arithmetic (Angluin et al. in PODC, 2006). [ABSTRACT FROM AUTHOR]

The present research work shows the development and implementation of a communications protocol of superior layers, which considers the layers session, presentation and applications, which will be transported through any Ethernet frame. This protocol has the primary objective to monitor and control the communication of the nodes belonging to the HAN network (SmartGrids) in a non-invasive physical layer level, using existent data networks where the proposed protocol will co-exist. This work will begin with a brief definition of the SmartGrids and HAN networks concept, to go on with an explanation of the theoretical development of the protocol, and ending with the implementation and brief traffic analysis which will show the functioning of the protocol. [ABSTRACT FROM AUTHOR]

In wireless sensor networks (WSN), the clustering technique reduces energy efficiency and network lifetime. In this paper, a Fuzzy-based clustering architecture is proposed for cooperative communication in WSN in order to overcome this issue. In this work, a Cluster Head (CH) is chosen based on the parameters residual energy, trust, signal-to-interference-plus-noise ratio and load. Then, the intra-cluster routing is performed using network coding-based probabilistic routing scheme. The fuzzy-based clustering protocol helps in determining the cooperative node (CN) which joins the cluster. Finally, particle swarm optimization is used to establish the optimum path between each CN and the CH for data transmission. The simulation results show that the proposed technique enhances the network lifetime and energy efficiency. [ABSTRACT FROM AUTHOR]

Cloud-based file systems are widely accepted and adopted for personal and business purposes in recent years. Statistics shows that ~25% of file operations from a typical user are random writes. Inherited from traditional disk-based file systems, most distributed file systems are also based on objects or chunks of fixed sizes, which work well for sequential writes but poorly for random writes. This paper investigates the design paradigm of variable-sized objects for a distributed file system, where a new file write interface is proposed to provide rich write semantics. A novel distributed file system named VarFS, is presented to incorporate variable object indexing, support the random write interface and remain POSIX compatible. VarFS reduces the amount of unnecessary data being read and the number of objects modified in face of updates and consequently alleviates the total amount of data transferred. VarFS is implemented based on Ceph and the performance measurements show that it can achieve 1-2 orders of magnitude less latency than Ceph on random writes. At the same time, the overhead for initial writes and re-writes is acceptable. [ABSTRACT FROM AUTHOR]

In Underwater Wireless Sensor Networks (UWSN), the existing scheduling technique causes propagation delay or overhead issue. Also the data collision is likely to occur. In order to overcome this issue, in this paper, we propose to design a cluster-based MAC protocol for collision avoidance and TDMA scheduling in UWSN. Initially, the clusters are formed and cluster heads (CHs) are elected as per the energy-efficient hierarchical clustering algorithm. The cluster members, which are one-hop neighbors of CH, schedule the data sending times for all cluster members. The energy consumption analytical model is derived to show the average energy consumed by each CH. Finally, conflict-free scheduling is performed by using Spatial- Temporal-Confliction-Table. This allows nodes to transmit at the same time as long as their packets arrive during different times at the intended destinations. Simulation results show that the proposed MAC protocol reduces the delay and energy consumption while by increasing the packet delivery ratio. [ABSTRACT FROM AUTHOR]

HTTP is recognized as the most widely used protocol on the Internet when applications are being transferred more and more by developers onto the web. Due to increasingly complex computer systems, diversity HTTP automated software (autoware) thrives. Unfortunately, besides normal autoware, HTTP malware and greyware are also spreading rapidly in web environment. Consequently, network communication is not just rigorously controlled by users intention. This raises the demand for analyzing HTTP autoware communication behaviour to detect and classify malicious and normal activities via HTTP traffic. Hence, in this paper, based on many studies and analysis of the autoware communication behaviour through access graph, a new method to detect and classify HTTP autoware communication at network level is presented. The proposal system includes combination of MapReduce of Hadoop and MarkLogic NoSQL database along with xQuery to deal with huge HTTP traffic generated each day in a large network. The method is examined with real outbound HTTP traffic data collected through a proxy server of a private network. Experimental results obtained for proposed method showed that promised outcomes are achieved since 95.1% of suspicious autoware are classified and detected. This finding may assist network and system administrator in inspecting early the internal threats caused by HTTP autoware. [ABSTRACT FROM AUTHOR]

Loop-Free Alternates (LFAs) are a local fast-reroute mechanism defined for IP networks. They are simple but suffer from two drawbacks. Firstly, some flows cannot be protected due to missing LFAs, i.e., this concept does not provide full protection coverage, which depends on network topology. Secondly, some LFAs cause loops in case of node or multiple failures. Avoiding those LFAs decreases the protection coverage even further. In this work, we propose to apply LFAs to OpenFlow-based networks. We suggest a method for loop detection so that loops can be avoided without decreasing protection coverage. We propose an implementation with OpenFlow that requires only a single additional flow rule per switch. We further investigate the percentage of flows that can be protected, not protected, or even create loops in different types of failure scenarios. We consider realistic ring and mesh networks as well as typical topologies for data center networks. None of them can be fully protected with LFAs. Therefore, we suggest an augmented fat-tree topology which allows LFAs to protect against all single link and node failures and against most double failures. [ABSTRACT FROM AUTHOR]

In this paper, we propose Virtual Id Routing (VIRO) a novel 'plug-&-play' non-IP routing protocol for future dynamics networks. VIRO decouples routing/forwarding from addressing by introducing a topology-aware, structured virtual id layer to encode the locations of switches and devices in the physical topology. It completely eliminates network-wide flooding in both the data and control planes, and thus is highly scalable and robust. VIRO effectively localizes the effect of failures, performs fast re-routing and supports multiple (logical) topologies on top of the same physical network substrate to further enhance network robustness. We have implemented an initial prototype of VIRO using Open vSwitch, and we extend it (both within the user space and the kernel space) to implement VIRO switching functions in VIRO switches. In addition, we use the POX SDN controller to implement VIRO's control and management plane functions. We evaluate our prototype implementation through emulation and in the GENI (the Global Environment for Network Innovations) testbed using many synthetic and real topologies. Our evaluation results show that VIRO has better scalability than link-state based protocols (e.g. OSPF and SEATTLE) in terms of routing-table size and control overhead, as well as better mechanisms for failure recovery. [ABSTRACT FROM AUTHOR]

The coexistence of various protocols for current network equipment leads to extremely complex network systems, which not only limit the development of network technologies, but also cannot meet the growing demands for cloud computing, big data, and service visualization applications, just to name a few. As a new network architecture, parallel networks are expected to revolutionize this situation and meet the evolving demands for network services. The main idea of a parallel network is to leverage upon software-defined networking to construct artificial networks, and then effectively optimize the network system operations via the interactions between actual and artificial networks. The foundation of the parallel network is the theory of ACP, composed of artificial societies, computational experiments, and parallel execution. By the computational experiments and analysis of the artificial network, a control strategy based on network traffic flow can be continuously updated and tracked on a real-time basis; meanwhile, the collected operating status of the actual network can also be used to optimize the model of the artificial network. These strategies can be applied to all types of network equipment to control network operations at various levels; thus, it is possible to allocate the network resources more effectively, improve the management and utilization of resources, and then provide new network solutions to effectively address the constantly evolving network demands for network performance, scalability, and security. [ABSTRACT FROM PUBLISHER]