Link Failures In Networks Research Articles

Edges deletion problem of hypercube graphs for some n

Numerous graph-theoretic methods can be used to investigate the efficiency and reliability of networks. The reliability of a network is determined based on its connectivity. At the very least, the system must continue to function in the event of part of its component (node or link) failures. An ideal system remains reliable even when errors occur. Diameter is a measure of network efficiency used to study the effects of link failures in networks. In this paper, we look into the eliminating edges affect to the hypercube graph’s diameter (call it by [Formula: see text]) and calculate the maximum diameter that is denoted by [Formula: see text] after deleting [Formula: see text] edges from hypercube graphs [Formula: see text] for some n.

Fuzzy Tree t -Spanners of Ratio Labelled Butterfly Network

Background/Objectives: The reliability and optimality of a communication system depend on the network that has a minimum distance. The minimum distance is the shortest path between the vertices. Even in error correction codes, the minimum Hamming distance ensures data integrity. Hence to have efficient routing protocols, the network is preferred to be a spanning tree that connects all the nodes of the communication system. As tree t- spanner is the optimization technique in determining minimum spanning tree, finding tree t-spanners of a ratio labelled fuzzy graph for the Butterfly network BF(n) is notion of this study. Methods: This study has introduced a new labelling called Ratio Labelling (RL) for examining the fuzziness in a crisp graph. Using the RL method, the crisp graphs were examined for the admittance of fuzziness and were thereby found, to have a tree t-spanners of ratio labelled fuzzy graphs. Findings: The quality of a network can be measured using the stretch factor of the network. The issues of network survival or link failures in a communication networks can be rectified by approximating the best flow spanner. As the optimal connectivity between the nodes is ensured by interconnection networks, the fuzzy tree t- spanners of undirected fuzzy Butterfly Network BF(n) are examined by labelling the vertices and edges using ratio labelling. The Breadth First Search (BFS) algorithm enhances the process of minimizing the spanning tree for an unweighted graph. Since the edge weightage is unique for all the edges of BF(n) under RL, searching for an edge with minimum weight by Kruskal’s algorithm or Prim’s algorithm are less meaningful. Hence, the BFS algorithm is adopted in finding the spanning tree T of Ratio Labelled BF(n). The bounds for the stretch factor t of a fuzzy tree t- spanner of ratio labelled BF(n) were obtained. Novelty: The literature survey shows that various classes of graphs were examined for the admissibility of tree t-spanners. Finding a tree t-spanner for a fuzzy graph was not found in literature, as per our knowledge. Extending the problem of finding a tree t -spanner of a ratio labelled fuzzy graph is an advancement in the field of fuzzy graphs. Keywords: Fuzzy Graph, Fuzzy distance, Ratio Labelling, Tree t- spanner, Butterfly Network

TIVC: An Efficient Local Search Algorithm for Minimum Vertex Cover in Large Graphs.

The minimum vertex cover (MVC) problem is a canonical NP-hard combinatorial optimization problem aiming to find the smallest set of vertices such that every edge has at least one endpoint in the set. This problem has extensive applications in cybersecurity, scheduling, and monitoring link failures in wireless sensor networks (WSNs). Numerous local search algorithms have been proposed to obtain "good" vertex coverage. However, due to the NP-hard nature, it is challenging to efficiently solve the MVC problem, especially on large graphs. In this paper, we propose an efficient local search algorithm for MVC called TIVC, which is based on two main ideas: a 3-improvements (TI) framework with a tiny perturbation and edge selection strategy. We conducted experiments on real-world large instances of a massive graph benchmark. Compared with three state-of-the-art MVC algorithms, TIVC shows superior performance in accuracy and possesses a remarkable ability to identify significantly smaller vertex covers on many graphs.

Traffic predictive-based flow splitting rerouting scheme for link failures in software-defined networks

This paper presents a traffic rerouting approach to keep a satisfactory QoS (Quality of Service) in virtualized network infrastructures (VPN, Cloud, etc.), supervised by an SDN (Software-Defined Networking) controller dealing with high traffic fluctuations. Traffic fluctuations are usually caused by link failures or link congestion and result in high packet loss, long delay times, and high jitter. These metrics are critical in computer network's QoS assessing. In our strategy, we combine traffic prediction in the SDN controller with flow splitting in the data plane. Simulations reveal that this strategy provides more satisfying values of the QoS assessment metrics compared to the literature.

A solution technique to cascading link failure prediction

The study of complex networks is a new powerful tool that can provide a profitable skeleton to better elucidate technology-related phenomena and interactions between components of real-world networks However, it is not easy to predict the communal behavior of such systems from their elements and on the other hand, the failure of one or few elements can trigger the failure of other elements throughout the network, resulting in network breakdown and catastrophic events at large scales. Therefore, developing predictive mathematical techniques to examine complex networks is one of the biggest challenges of the present time. Knowing that link failure prediction is less studied in the OR literature, the present study articulates a method to predict link failures in complex networks, which is primarily based on Bayesian Belief Networks (BBN) and TOPSIS. The method aims to predict failures based on the affective factors of failures in networks. To this end, effective factors of failures are first detected, and then the graph of the relationship of factors along with their weight is determined. After all, the method provides the prediction for future damaged components. The functionality of the method is validated by an extensive computational analysis employing simulation in scale-free, random, and actual international aviation networks and its performance is compared with other benchmark algorithms. The results and sensitivity analysis experiments arrive at prominent managerial insights and efficacious implications and show that our method can generate high-quality solutions in many networks.

An Innovative Prediction of Link Failure and Node Lifetime in Mobile Ad Hoc Networks Using Grey Wolf Optimization

The Path Restoration System in Mobile Ad hoc Network (MANET) was tough due to the changing environment. Data packets are lost if a link is broken while delivering information, and the system is vulnerable to various assaults. Considering this, we propose the Grey Wolf Optimization technique (GWO) to predict connection failure, link and node lifetime before broadcasting packets to avoid packet loss. To define the path, we used the Route Information Protocol (RIP). Following that, GWO is manually played; with this method, this research forecasts the node and lifetime, and achieves a packet delivery ratio of 0.7. The proposed Gray-Wolf algorithm achieves an efficient packet transmission rate and improves the early detection of links and node lifetimes to maintain path stability for data transmission. The proposed model reduces end-to-end delay, overhead, and packet drop. It improves the residual energy of nodes and the packet delivery ratio. Grey Wolf Optimization is one of many examining boosting methods activated by the grouping within the wolf family and the special hunting techniques used by grey wolves. As a result, the Grey Wolf optimization method was used to find the optimal result by mocking the overall characteristics of the grey wolf colony.

Self-Healing and Shortest Path in Optical Fiber Sensor Network

In this study, a new square-based fiber Bragg grating (FBG) sensor network model is proposed to address possible link failures in FBG sensor networks and improve their reliability. Graph theory and optical switching are simultaneously applied to these sensor networks to improve their self-healing ability; the FBG sensor network is regarded as a directed graph. Three commonly used self-short-circuit algorithms are compared in terms of the self-healing capabilities that they provide to the optical fiber sensor network. Among these, the shortest-path faster algorithm achieved a high, nearly 90% repair accuracy and had an average repair time of 0.103 s, the shortest in this study. The newly designed FBG self-healing network can be reorganized and repaired when local damage occurs, thereby improving its reliability.

Reliable Multipath Flow for Link Failure Recovery in 5G Networks Using SDN Paradigm

In modern networks and cloud evolution, as new nodes to internetwork growing rapidly and use of gaming and video streaming over the network require high availability with very small latency rate. 5G networks provides muchfaster services than 4G but link failure occurrence can affect the quality of service. In 5G networks environmentalfactors also affect the efficiency of wireless signals. To overcome such type of issues, base stations are placed indistributed manner around urban areaswhen decision is required for the placement. However, in some scenarioswe can have few similarities, as in general, highways are same. In existed systems signals distribution is performedhomogenously, so it will be generating issues like fractal and environmental. It will be cause of great economicloss. However, being an emerging network paradigm, Software defined Network (SDN) is easy to manage due tological separation of control plane and data plane. SDN supports numerous advantages, one of them is link robustness to avoid service unavailability. To cope with network link failures there are many mechanisms existedlike proactive and reactive mechanisms, but these mechanisms calculate multiple paths and stored in flow tableswithout considering reliability of link. Therefore, it will be cause of high latency rate due to calculation of manymultiple paths and increased traffic overhead too. To overcome these issues, we proposed a new approach in whichmultipath numbers depend on reliability of primary path. Number of alternative paths decreased as reliability oflink increased it leads to less time required to calculate alternative path. In addition, traffic overhead decreases ascompared to existing approaches. Secondly, we also integrate the shortest distance factor with reliability factor,and we get better results than existing approaches. Our proposed system will be helpful in increasing the availability of services in 5G network due to low latency rate and small traffic overhead required in link failure recovery

Topological theory of resilience and failure spreading in flow networks

Link failures in supply networks can have catastrophic consequences that can lead to a complete collapse of the network. Strategies to prevent failure spreading are thus heavily sought after. Here, we make use of a spanning tree formulation of link failures in linear flow networks to analyse topological structures that prevent failures spreading. In particular, we exploit a result obtained for resistor networks based on the \textit{Matrix tree theorem} to analyse failure spreading after link failures in power grids. Using a spanning tree formulation of link failures, we analyse three strategies based on the network topology that allow to reduce the impact of single link failures. All our strategies do not reduce the grid's ability to transport flow or do in fact improve it - in contrast to traditional containment strategies based on lowering network connectivity. Our results also explain why certain connectivity features completely suppress any failure spreading as reported in recent publications.

Resilience Evaluation of Multi-Path Routing against Network Attacks and Failures

The current state of security and availability of the Internet is far from being commensurate with its importance. The number and strength of DDoS attacks conducted at the network layer have been steadily increasing. However, the single path (SP) routing used in today’s Internet lacks a mitigation scheme to rapidly recover from network attacks or link failure. In case of a link failure occurs, it can take several minutes until failover. In contrast, multi-path routing can take advantage of multiple alternative paths and rapidly switch to another working path. According to the level of available path control, we classfy the multi-path routing into two types, first-hop multi-path (FMP) and multi-hop multi-path (MMP) routing. Although FMP routing supported by networks, such as SD-WAN, shows marginal improvements over the current SP routing of the Internet, MMP routing supported by a global Internet architecture provides strong improvement under network attacks and link failure. MMP routing enables changing to alternate paths to mitigate the network problem in other hops, which cannot be controlled by FMP routing. To show this comparison with practical outcome, we evaluate network performance in terms of latency and loss rate to show that MMP routing can mitigate Internet hazards and provide high availability on global networks by 18 participating ASes in six countries. Our evaluation of global networks shows that, if network attacks or failures occur in other autonomous systems (ASes) that FMP routing cannot avoid, it is feasible to deal with such problems by switching to alternative paths by using MMP routing. When the global evaluation is under a transit-link DDoS attack, the loss rates of FMP that pass the transit-link are affected significantly by a transit-link DDoS attack, but the other alternative MMP paths show stable status under the DDoS attack with proper operation.

An efficient approach to robust controller placement for link failures in Software-Defined Networks

In Software-Defined Networks (SDN), one of the critical research challenges for large-scale deployment of SDN is controller placement problem (CPP). However, link failures are critical security issues in networks and greatly impact SDN’s robustness. The CPP for link failures is still challenging today. To this end, we study the CPP for multi-link failures (CPP-MLF). Firstly, we investigate the real link data of today’s networks to analyze the characteristics of link failures and formalize the link failure rate. Next, we formulate minimizing the number of controllers and worst-case delay as the optimization objectives of CPP-MLF and develop a heuristic algorithm based on improved NSGA-II to solve CPP-MLF efficiently. Specifically, we improve the non-dominated set and crowding distance for the NSGA-II by dynamic competition mechanism and even distribution operator, respectively, thereby quickly obtaining the Pareto-optimal solutions of CPP-MLF. Afterwards, we introduce controller load variance to evaluate them to make a satisfactory decision on controller placement. We conduct simulations with real network topologies, and the results show that the proposed heuristic algorithm performs well on the number of controllers, worst-case delay and robustness, while producing acceptable runtime overheads.

Confidentiality meets protection in elastic optical networks

This work considers the joint problem of securing confidential demands against eavesdropping attacks and protecting the network against link failures in elastic optical networks (EONs). Network coding is used to provide security for confidential connections by encrypting the data through XOR operations at the physical layer with other established connections in the network. Backup paths are also computed for protecting the primary path of the confidential connections, while ensuring that the level of security for the confidential demands is preserved in case of a link failure on the primary path or on any of the paths involved in the XOR process. A realistic network scenario is modeled, where four different classes of connections are considered with respect to their protection and security requirements, while a combination of novel integer linear programming (ILP) and heuristic algorithms are used to establish each class of demands in the network. The proposed algorithms are evaluated in terms of spectrum utilization, network blocking, and level of security provided. From the results obtained it is evident that confidential connections can be transmitted in a secure manner, while for the classes that require both security and protection, the connections retain their required level of security in the event of any single link failure in the network.

A parallel cross-connection recovery scheme for dual link failure in elastic optical networks

Abstract In this paper, we proposed a fast recovery strategy for a dual link failure (DLF) in elastic optical network (EON). The EON is a promising solution to meet the next generation higher bandwidth demand. The survivability of high speed network is very crucial. As the network size increases the probability of the DLF and node failure also increases. Here, we proposed a parallel cross connection backup recovery strategy for DLF in the network. The average bandwidth blocking probability (BBP), bandwidth provisioning ratio (BPR), and recovery time (RT) for our proposed Intermediate node cross-connect backup for shared path protection (INCB-SPP) for ARPANET are 0.38, 2.71, 4.68 ms, and for DPP 0.70, 6.02, 8.71 ms and for SPP 0.40, 2.87, and 16.33 ms respectively. The average BBP, BPR, and RT of INCB-SPP for COST239 are 0.01, 1.71, 3.79 ms and for DPP are 0.39, 3.50, 8.20 ms and SPP are 0.04, 1.75, and 12.47 ms respectively. Hence, the proposed strategy shows lower BBP, fast connection recovery, and BPR when compared with the existing shared path protection (SPP) and dedicated path protection (DPP) approaches. Simulation is performed on ARPANET and COST239 topology networks.

Recovery of a single link failure in all-optical networks based on the cuckoo search algorithm

Recovery of a single link failure in all-optical networks based on the cuckoo search algorithm

Recovery of a single link failure in all-optical networks based on the cuckoo search algorithm

Recovery of a single link failure in all-optical networks based on the cuckoo search algorithm

WITHDRAWN: Resource efficient recovery scheme for double link failures in elastic optical networks

Abstract In order to avoid, double link failure in the optical network, we proposed a rapid connection recovery scheme for the survivable double link in elastic optical network (EON). The elastic optical network provides very high and flexible bandwidth as per the user’s requirement. Larger network have more number of failure probability. To control such failure, our proposed strategy provides a alternate backup light path by using minimum resources. Our proposed recovery scheme (PRS) provide better results in terms of recovery time, bandwidth blocking probability (BBP), and bandwidth provisioning ratio, when compared with the existing shared path protection (SPP) and dedicated path protection (DPP) schemes. ARPANET and COST239 topologies are considered for simulation.

Asynchronous Non-Blocking Algorithm to Handle Straggler Reduce Tasks in Hadoop System

Hadoop is widely adopted as a big data processing application as it can run on commercial hardware at a reasonable time. Hadoop uses asynchronous blocking concurrency using Thread and Future class. Therefore, in some cases such as network link or hardware failure, a running task may block other tasks from running (the task becomes straggler). Hadoop releases are equipped with algorithms to handle straggler tasks problem. However, the algorithms manage Map and Reduce task similarly, while the straggler root cause might be different for both tasks. In this paper, the Asynchronous Non-Blocking (ANB) method is proposed to improve the performance and avoid the blocking of Reduce task in Hadoop. Instead of using the single queue, our approach uses two queues, i.e. task queue and callback queue. When a task is not ready or detected as a straggler, it is removed from the main task queue and temporarily sent to the callback queue. When the task is ready to run, it will be sent back to the main task queue for running. The performance of the algorithm is compared with rTuner, the latest paper found on handling straggler task in Reduce task. From the comparison, it is shown that ANB consistently gives faster time to complete because any unready tasks will be directly put into the callback queue without blocking other tasks. Furthermore, the overhead time in rTuner is high as it needs to check the straggler status and to find the reason for a task to become straggler.

Survivable virtual network mapping with content connectivity against multiple link failures in optical metro networks

Network connectivity, i.e., the reachability of any network node from all other nodes, is often considered as the default network survivability metric against failures. However, in the case of a large-scale disaster disconnecting multiple network components, network connectivity may not be achievable. On the other hand, with the shifting service paradigm towards the cloud in today’s networks, most services can still be provided as long as at least a content replica is available in all disconnected network partitions. As a result, the concept of content connectivity has been introduced as a new network survivability metric under a large-scale disaster. Content connectivity is defined as the reachability of content from every node in a network under a specific failure scenario. In this work, we investigate how to ensure content connectivity in optical metro networks. We derive necessary and sufficient conditions and develop what we believe to be a novel mathematical formulation to map a virtual network over a physical network such that content connectivity for the virtual network is ensured against multiple link failures in the physical network. In our numerical results, obtained under various network settings, we compare the performance of mapping with content connectivity and network connectivity and show that mapping with content connectivity can guarantee higher survivability, lower network bandwidth utilization, and significant improvement of service availability.

Opti-PUM: An Optimal Policy Update Mechanism for Link Failure Prevention in Mobile SDWM-IoT Networks

Due to the limited resources and several implementation challenges, frequent link failure is a serious concern in mobile wireless mesh-based Internet of Things (WM-IoT) networks. The unique features of software defined networking (SDN), such as global visibility, network programmability, etc., help to improve the fault tolerance and network management in IoT networks. The integration of SDN and WM-IoT networks leads to a new domain, called software defined WM-IoT (SDWM-IoT) networks. This article discusses the problems caused by the frequent link failures in mobile SDWM-IoT networks. Most of the existing works focus on link failure prevention by precomputing backup paths, link monitoring-based failure detection, etc. However, limited efforts have been devoted for adaptive multiconstrained link failure prevention. This article proposes a proactive optimal policy update mechanism, named Opti-PUM. It is formulated in a promising algebraic modeling language (AMPL), and is solved using a well-known algebraic solver (CPLEX). Opti-PUM is tested under various network scenarios. Additionally, the proposed approach is also implemented in Mininet-WiFi and the obtained results are compared with some well-known existing algorithms. The comparison shows that Opti-PUM helps to achieve the packet delivery ratio (PDR) and packet loss ratio (PLR) improvement of <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"/> 12.18% <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"/> and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"/> 11.68% <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"/> , respectively. Similarly, an average delay and jitter improvement of <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"/> 35.93% <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"/> and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"/> 31.72% <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"/> have also been achieved.

Collective effects of link failures in linear flow networks

The reliable operation of supply networks is crucial for the proper functioning of many systems, ranging from biological organisms such as the human blood transport system or plant leaves to man-made systems such as power grids or gas pipelines. Whereas the failure of single transportation links has been analysed thoroughly, the understanding of multiple failures is becoming increasingly important to prevent large scale damages. In this publication, we examine the collective nature of the simultaneous failure of several transportation links. In particular, we focus on the difference between single link failures and the collective failure of several links. We demonstrate that collective effects can amplify or attenuate the impacts of multiple link failures—and even lead to a reversal of flows on certain links. A simple classifier is introduced to predict the overall strength of collective effects that we demonstrate to be generally stronger if the failing links are close to each other. Finally, we establish an analogy between link failures in supply networks and dipole fields in discrete electrostatics by showing that multiple failures may be treated as superpositions of multiple electrical dipoles for lattice-like networks. Our results show that the simultaneous failure of multiple links may lead to unexpected effects that cannot be easily described using the theoretical framework for single link failures.