Backup Paths Research Articles

Failure-Aware Protection for Many-to-Many Routing in Content Centric Networks

Network communications can easily be disrupted by the failure of networking equipment, ranging from a single accidental link cut, to a wide swath of links and nodes wiped out simultaneously by a natural disaster. To mitigate the impact of these failures, survivability solutions involving precomputed backup paths can be used to help maintain connectivity and reduce service downtime. Further improvements to reliability can be gained through the use of on-path caching inherent in Content Centric Networking (CCN). CCN is an alternative networking paradigm that puts the focus on efficiently providing consumers access over the network to content held by producers. As content is returned from a producer, it can be cached at the intermediate routers, allowing that content to be replicated and forwarded out to all known consumers asking for that content. We aim to improve the reliability of CCN by proposing routing algorithms for connecting many consumers to a set of producers with paths that are survivable in respect to a flexibly-sized failure set. These survivable routes are enhanced through the use of failure aware on-path caching that allows consumers to access content even after the primary connections to producers are severed.

Усовершенствование функций маршрутизации и сигнализации протокола PNNI с целью повышения устойчивости сети связи

The improved routing and signaling functions of PNNI protocol is presents in the paper. The improved this function of PNNI protocol are to use topological network redundancy and create backup paths. This improved PNNI provides high network stability, if the network topology changes rapidly.

Congestion-Free Transient Plane (CFTP) Using Bandwidth Sharing During Link Failures in SDN

Abstract Software-defined networking (SDN) is an emerging trend where the control plane and the data plane are separated from each other, culminating in effective bandwidth utilization. This separation also allows multi-vendor interoperability. Link failure is a major problem in networking and must be detected as soon as possible because when a link fails the path becomes congested and packet loss occurs, delaying the delivery of packets to the destination. Backup paths must be configured immediately when a failure is detected in the network to speed up packet delivery, avoid congestion and packet loss and provide faster convergence. Various SDN segment protection algorithms that efficiently reduce CPU cycles and flow table entries exist, but each has drawbacks. An independent transient plane technique can be used to reduce packet loss but is not as efficient when multiple flows try to share the same link. The proposed work focuses on reducing congestion, providing faster convergence with minimal packet loss and effectively utilizing link bandwidth using bandwidth-sharing techniques. An analysis and related studies show that this method performs better and offers a more reliable network without loss, while simultaneously ensuring the swift delivery of data packets toward the destination without congestion, compared to the other existing schemes.

Building $k$ -Protected Routes in Multi-Hop Cognitive Radio Networks

In cognitive radio networks (CRNs), the established communication sessions between secondary users (SUs) may be affected or even get interrupted because the SUs need to relinquish a spectrum when the primary users (PUs) become active again. On detecting PU activities, the SUs on the interrupted links either switch to another link operating on another spectrum fragment using the same one-hop path, or the SUs seek for an alternative multi-hop backup path. In either approach, the communication session is destined to experience a delay or even gets interrupted, which is intolerable to quality of service-sensitive applications such as multimedia streaming or audio/video conferencing. In this paper, we study the problem of building ${k}$ -protected routes in CRNs. A ${k}$ -protected route consists of a set of main link s with preassigned backup links and backup path s so that the ${k}$ -protected route is guaranteed to endure ${k}$ PU appearances without being interrupted. For a CRN, we find a ${k}$ -protected route for each session request and maximize the number of sessions that the CRN can support. We propose both centralized and distributed algorithms for the ${k}$ -protected routing problem. Simulation results show that our ${k}$ -protected routes outperform existing opportunistic spectrum switching approaches regarding delay and interruption rate.

Metro: An Efficient Traffic Fast Rerouting Scheme With Low Overhead

Failure is common instead of exception in large-scale networks. To provide high service quality to upper-layer applications, it is desired that a converged backup path can be rapidly launched when failure occurs. In this paper, we design an IP based Fast ReRouting (FRR) scheme called Metro, which can solve the traffic rerouting convergence problem after arbitrary single link/node failure with low stretch for the backup path. When failure occurs in the network, Metro first indicates all the network areas that would be affected by the failure, and then finds out a few bridge links to drain the traffic in the affected network area to the network area that is not affected by the failure. In this way, Metro does not configure tunnels, encapsulate or modify data packets, and hence it is easy to be deployed in current networks. Extensive simulations show that Metro can solve arbitrary single link/node failure with backup paths shorter than the state-of-the-art solutions, and about 98% of the backup path stretch in Metro are the same as the optimal tunnel scheme.

Spectrum Expansion/Contraction and Survivable Routing and Spectrum Assignment problems on EONs with time-varying traffic

For serving time-varying traffic on an Elastic Optical Networks (EONs), the spectrum allocated previously for the connection request should be expanded or contracted to meet the traffic requirement. For the survivable connection, both the primary and the backup lightpaths of the connection request should be expanded/contracted at the same time. In this paper, the Survivable Routing and Spectrum Allocation (SRSA) problem and the Spectrum Expansion Contraction (SEC) problem for SRSA on EONs with time-varying traffic are studied. In this article, two protecting schemes, Dedicated Path Protection (DPP) and Shared Backup Path Protection (SBPP) are considered. For each protecting scheme, two dynamic survivable routing algorithms and the respective SEC operations are developed to solve it. In the proposed algorithms, both the weighted hop distance and spectrum fragmentation are considered jointly. These algorithms are examined through simulations to find the best parameter for each algorithm. The results show that the blocked ratio (BR) of requests can be reduced by about 3%, if the spectrum fragmentation is considered. And, using SEC operation in time-varying traffic can reduce the BR of request about 1% and speed up the computation compared to the normal release and add operation.

MODEL OF DATA TRAFFIC QOS FAST REROUTING IN INFOCOMMUNICATION NETWORKS

The subject of research in the article is the processes of fast rerouting with the protection of the Quality of Service level in infocommunication networks. The aim of the work is the development of a mathematical model of Fast ReRouting with the protection of the Quality of Service level by the bandwidth and probability of packet loss for data traffic. The following tasks are solved in the article: development and research of a fast rerouting flow-based model with the protection of the Quality of Service level of data traffic in the infocommunication network. The following methods are used: the graph theory, the teletraffic theory, the queuing theory, and mathematical programming methods. The following results were obtained: the fast rerouting flow-based model was developed and investigated, which, due to the introduced protection conditions on indicators of bandwidth and packet loss probability, allows providing the Quality of Service along both the primary and backup multipath. Conclusions: Within the framework of the proposed flow-based model, the fast rerouting technological task was formulated as an optimization problem with the constraints of the conditions of implementation of the multipath routing strategy, conditions of flow conservation, and conditions of protection of the link, node, and level of Quality of Service in terms of bandwidth and packet loss probability. The application of this solution contributes to the optimal use of the available network resource while providing the specified level of Quality of Service in terms of bandwidth and probability of packet loss along both the primary and backup routes in the case of a failure of the infocommunication network elements. The proposed flow-based model can be used as the basis of the algorithmic software of existing routers and/or controllers of Software-Defined Networks, which are responsible for the calculation of the primary and backup paths in the fast rerouting of data traffic sensitive to such Quality of Service indicators as bandwidth and packet loss probability.

Packet Transport Network Recovery System with Examination of Data Transmission Quality

A packet transport network recovery system based on failure pattern under examination of transmission quality is proposed. Network failures are segmented into one of the three patterns: single failure of a node, failures of multiple nodes, and failures of multiple network areas. The single failure is recovered by a protection scheme. For failures of multiple nodes or multiple areas, recovery is performed by a node-based multiple-backup operation plane scheme or by an area-based multiple-back operation plane scheme, respectively. A unique recovery ID is assigned to each failure pattern and backup paths with the recovery ID are stored in each node. When network failures occur, the network management server determines the type of failure and sends the appropriate recovery ID to the nodes. Then recovery paths are configured. Our proposed system took about 0.5[Formula: see text]s to configure 1000 backup paths after failures were detected, compared to about 4[Formula: see text]s by a conventional scheme. For the examination of data transmission quality, multiple paths that do not share the same link are grouped and configured concurrently. The number of groups is regarded as the performance of the configuration. The performance of the proposed system is about three times faster than a configuration without grouping.

Self-healing and SDN: bridging the gap

Achieving high programmability has become an essential aim of network research due to the ever-increasing internet traffic. Software-Defined Network (SDN) is an emerging architecture aimed to address this need. However, maintaining accurate knowledge of the network after a failure is one of the largest challenges in the SDN. Motivated by this reality, this paper focuses on the use of self-healing properties to boost the SDN robustness. This approach, unlike traditional schemes, is not based on proactively configuring multiple (and memory-intensive) backup paths in each switch or performing a reactive and time-consuming routing computation at the controller level. Instead, the control paths are quickly recovered by local switch actions and subsequently optimized by global controller knowledge. Obtained results show that the proposed approach recovers the control topology effectively in terms of time and message load over a wide range of generated networks. Consequently, scalability issues of traditional fault recovery strategies are avoided.

A Flexible, Natural Formulation for the Network Design Problem with Vulnerability Constraints

Given a graph, a set of origin-destination (OD) pairs with communication requirements, and an integer k ≥ 2, the network design problem with vulnerability constraints (NDPVC) is to identify a subgraph with the minimum total edge costs such that, between each OD pair, there exist a hop-constrained primary path and a hop-constrained backup path after any k − 1 edges of the graph fail. Formulations exist for single-edge failures (i.e., k = 2). To solve the NDPVC for an arbitrary number of edge failures, we develop two natural formulations based on the notion of length-bounded cuts. We compare their strengths and flexibilities in solving the problem for k ≥ 3. We study different methods to separate infeasible solutions by computing length-bounded cuts of a given size. Experimental results show that, for single-edge failures, our formulation increases the number of solved benchmark instances from 61% (obtained within a two-hour limit by the best published algorithm) to more than 95%, thus increasing the number of solved instances by 1,065. Our formulation also accelerates the solution process for larger hop limits and efficiently solves the NDPVC for general k. We test our best algorithm for two to five simultaneous edge failures and investigate the impact of multiple failures on the network design.

Reliability Measurement in A Multi-path Transmission Network using SMP-BP Algorithm

Data security is very important in the multi-path transmission networks (MTN). Efficient data security measurement in MTN is crucial so as to ensure the reliability of data transmission. To this end, this paper presents an improved algorithm using single-single minimal path based back-up path (SSMP-BP), which is designed to ensure the data transmission when the second path is out of work. From the simulation study, the proposed algorithm has the better network reliability compared with existing double minimal path based backup path (DMP-BP) approach. It could be found that, the proposed algorithm uses less back-up paths compared with DMP-BP so that less network resources like nodes are achieved.

Pipeline slot based fast rerouting scheme for delay optimization in duty cycle based M2M communications

In recent years, with the development of networked Cyber-Physical Systems (CPSs), wireless sensor networks (WSNs), as an important carrier of CPSs, has been applied more and more. In WSNs, many applications require low delay and high reliability for routing the sensing data to sink. Due to the lossy nature of wireless channels, rerouting schemes are often applied to ensure reliable data collection for mission-critical applications. However, rerouting together with multi-hop routing in duty cycle base WSNs will make designing a low delay routing scheme a challenge issue. In this paper, a Pipeline Slot based Fast Rerouting (PSFR) Scheme is proposed to reduce delay in duty cycle based WSNs. The main innovation points of PSFR scheme are as follows: (a) In duty cycle based WSNs, the major delay is caused by the sleep delay when nodes in the route forwarding to next hop node. Therefore, in PSFR scheme, we add a sequential active (SA) slot at the next hop node which is active at the next slot of the active slot of the previous node, which enables the previous node to forward packets to the next hop node in the slot right after receiving packet in active slot and greatly reduces sleep delay. (b) The second, in PSFR scheme, the backup path is designed beforehand in a less stringent pipeline active slot, so the packet can reach the sink with a relatively low delay when rerouting. (c) More importantly, in PSFR scheme, the added SA slots use the residual energy of peripheral nodes, which means they reduce the routing delay without decreasing network lifetime. After sufficient theoretical analysis and experiment, results show that the PSFR scheme can reduce the delay by more than 58.215% in the experiment networks without reducing the network lifetime, and the PSFR scheme can improve the energy utilization of network by more than 27.66%.

An offline cost-efficient strategy for multicast traffic protection in WDM optical mesh networks to aid rapid recovery

The most effective way of providing popular user services such as high-definition television, video conferencing and distributed gaming over the Internet is multicasting. Protecting multicast sessions against single link failure or a fiber cut in the WDM optical backbone is thus vital. Protection schemes involve reserving resources for backup paths that remain idle during normal fault-free operation. It is thus important to design protection or survivability schemes that consume as few extra resources as possible. A number of protection schemes for multicast sessions exist in the literature but only few can provide rapid recovery. In this paper we propose a new offline strategy for ensuring survivability of multicast traffic that can aid rapid recovery from a link failure. Our strategy is designed to achieve significant resource saving while providing recovery speed comparable to 1:1 dedicated path protection. We first propose an Integer Linear Program formulation to solve the problem optimally for small networks and then a heuristic for large networks. Performance comparisons show that our heuristic performs better than two well-known heuristics and also produces near optimal results. Time complexity analysis further shows that our heuristic runs in polynomial time.

FDVRRP: Router implementation for fast detection and high availability in network failure cases

High availability and reliability have been considered promising requirements for the support of seamless network services such as real‐time video streaming, gaming, and virtual and augmented reality. Increased availability can be achieved within a local area network with the use of the virtual router redundancy protocol that utilizes backup routers to provide a backup path in the case of a master router failure. However, the network may still lose a large number of packets during a failover owing to a late failure detections and lazy responses. To achieve an efficient failover, we propose the implementation of fast detection with virtual router redundancy protocol (FDVRRP) in which the backup router quickly detects a link failure and immediately serves as the master router. We implemented the FDVRRP using open neutralized network operating system (OpenN2OS), which is an open‐source‐based network operating system. Based on the failover performance test of OpenN2OS, we verified that the FDVRRP exhibits a very fast failure detection and a failover with low‐overhead packets.

Evalusi Kinerja Hot Standby Router Protocol (HSRP) dan Gateway Load Balancing Protocol (GLBP) untuk Layanan Video Streaming

Realtime (streaming) data communication has become a major requirement for companies and government institutions. Communication that occurs is not only limited to one particular local area but covers other areas so as to form a broad network (WAN). In building network infrastructure, one of the most important things is how networks can deal with failure (failure) on a computer network consists of failure of devices (devices) that affect Quality of Services (QoS). In every internet network design process, a redundant line is always added to complete the main line. So that if the main line is disrupted, data traffic can be transferred to the backup path, this process is called network redundancy. So that if one gateway dies, another gateway will immediately replace the dead gateway. There are two protocols included in the FHRP, namely Hot Standby Routing Protocol (HSRP), and Gateway Load Balancing Protocol (GLBP), these two protocols that can overcome this problem. So from that this study will discuss which protocol between the two protocols has the best performance in overcoming the problem. Methods of data collection with literature studies and literature studies, simulations carried out with 8 stages (problem formulation, conceptual models, input & output data, modeling, simulation, verification & validation, experimentation, and output analysis). The results of this study provide the best QoS value for the delay value is the HSRP ROUTER protocol, and for the value of packet loss is HSRP, and for throughput value is HSRP and the routing protocol that is appropriate for the network for video streaming services is HSRP

Forwarding Rule Multiplexing for Scalable SDN-Based Internet of Things

Internet of Things (IoT) provides a vast number of devices with heterogeneous characteristics connected to the Internet. As a promising networking paradigm that decouples control plane from data plane, software-defined networking (SDN) is an appropriate architecture for IoT. The SDN paradigm supports deploying traffic flows dynamically by a centralized controller to SDN switches. In particular, the controller configures forwarding rules of SDN switches to steer traffic. However, forwarding rules are usually stored in expensive and power hungry ternary content addressable memory (TCAM), which is very limited in quantity for SDN switches. Thus, the shortage of TCAM becomes a fatal bottleneck for scalable flow management for SDN-based IoT. To this end, we propose a method of forwarding rule multiplexing (FRM) to minimize the total number of forwarding rules in SDN-based IoT. We multiplex different traffic flows traversing through the same path into an aggregated flow with the label of VLAN ID. As a result, multiple forwarding rules could be merged into one multiplexed rule. We also extend the method to SDN protection against link failure, and reduce backup path forwarding rules. We formulate the FRM problem as an integer linear programming model. Since the problem is NP-hard, we design a polynomial algorithm using the Markov approximation technique. Theoretical analysis indicates that the polynomial algorithm generates near-optimal solution. The extensive emulation results show that the proposed Markov approximation-based algorithm reduces the number of forwarding rules by 15.73% in average compared with the benchmark algorithms.

Implementation of FPGA‐based MPLS‐TP linear protection switching for 4000 + tunnels in packet transport network for optical carrier Ethernet

A packet transport network (PTN) for optical carrier Ethernet needs to be reliable even in a case that a fault occurs on a data path. To survive from the network fault, protection switching which sends data traffic to a pre-established backup path can be implemented on optical PTN systems. Linear protection switching in a multi-protocol label switching - transport profile (MPLS-TP) environment requires to be performed with sub-50 ms for multiple faults on data paths (i.e. tunnels). The linear protection switching for the recovery from multiple faults at almost ten tunnels can be processed on CPU. In this study, a packet transport layer protection switching integrated circuit (PPSI) is developed to increase the number of multiple protection switchings (e.g. 4000 + tunnels) with satisfying the strict requirement on sub-50 ms switching time, by processing on a field-programmable gate array (FPGA). The performance of this FPGA implementation is compared with that of the processed on CPU. Furthermore, this study investigates four message forwarding methods of set-bridge-and-selector and automatic protection coordination protocol messages to enhance the performance of the PPSI. The four methods are evaluated using an FPGA test-bed, in terms of switching time and the number of tunnels.

A Hybrid Approach for Providing Improved Link Connectivity in SDN

Software-Defined Networking (SDN) is a unique approach to design and build networks. The networks services can be better handled by administrators with the abstraction that SDN provides. The problem of re-routing the packets with minimum overhead in case of link failure is handled in this work. Protection and restoration schemes have been used in the past to handle such issues by giving more priority to minimal response time or controller overhead based on the use case. A hybrid scheme has been proposed with per-link Bidirectional forwarding mechanism to handle the failover. The proposed method makes sure that the controller overhead does not impact the flow of packets, thereby decreasing the overall response time, even with guaranteed network resiliency. The computation of the next shortest backup path also guarantees that the subsequent routing of packets always chooses the shortest path available. The proposed method is compared with the traditional approaches and proven by results to perform better with minimal response time.

A novel multiple communication paths for surgical telepresence videos delivery of the maxilla area in oral and maxillofacial surgery

A surgical telepresence between two surgical sites where a local surgeon in the surgery site, who is less experienced, needs help from the expert surgeon located at a remote site. Furthermore, the primary aim of this paper is to improve the quality of surgical video sent and received to-and-from both surgical sites, which has been a major quality issue so far. This work considers flow rate allocation and resource availability to determine the network path quality. Furthermore, a segmented backup path is used to provide a timely recovery in case of failure in the link. A neighbour detection technique in segmented backup is used to reduce the detection latency of the network in case of link failure. The results depict that the proposed system improves the quality of the surgical video by an average of 5.5db over the current system. Furthermore, the neighbour detection technique detects the network failure 40-45% faster than the currently used end-to-end detection system. The experimental results have done on the maxilla areas in oral and maxillofacial surgery. The proposed system concentrates on reducing the network failure detection latency and improves the received and sent video quality by using an enhanced path quality technique. Thus, this study enhances the video quality and provides a backup option in case of failure, which offers timely recovery for communication between two surgeons.

Risk Minimization Routing Against Geographically Correlated Failures

Regional failures, such as natural disaster or malicious attack, have become a major threat to the construction of future reliable communication network. The regional failures usually cause a large number of disconnected nodes simultaneously and influence the network for a long time. However, a routing scheme that is resilient to such geographically correlated failures is still unexplored. In this paper, we provide a comprehensive study of the disaster resilient routing dealing with the regional failure in operational IP backbone networks. It is notable that the path with minimal risk (i.e., minimal failure probability) is not necessarily the shortest path. The main challenge of finding such paths is that regional failure is unpredictable in terms of time, location, and the affected area. To this end, in combination with the computational geometry tool, we develop effective algorithms to find the minimal risk path between end node pairs to tolerate random regional failures. We show that in contrast to the conventional shortest path, a little longer path can be more effective to the disasters. After selecting such a path as the primary path, we turn to find a secondary backup path. In contrast to the conventional single link/node failure, a regional failure disrupts a large number of network components, simultaneously. As a result, how to find backup paths for re-establishment of the corrupted paths will raise a novel fairness issue. Specifically, during the backup path allocation, we focus on routing fairness to bound the worst-case user experience. A metric is proposed based on which an ILP is formulated. The extensive simulations validate that such an issue is non-negligible in face of regional failure scenarios.