Optical Switching and Networking最新文献

{"title":"Crafting optimal and resilient iBGP-IP/MPLS overlays for transit backbone networks","authors":"Cristina Mayr,&nbsp;Claudio Risso,&nbsp;Eduardo Grampín","doi":"10.1016/j.osn.2021.100635","DOIUrl":"https://doi.org/10.1016/j.osn.2021.100635","url":null,"abstract":"<div><p><span>The Internet is a collection of interconnected Autonomous Systems (ASes) that use the Border Gateway Protocol (BGP) to exchange </span>reachability<span><span> information. In this regard, BGP stability and scalability in the inter-domain scope have been matters of major concern for many years, and network engineers have been applying several techniques to cope with these issues. BGP is also used intra-domain (internal BGP - iBGP), to disseminate reachability information inside each AS, and works together with the Interior Gateway Protocols<span> (IGPs) such as OSPF or IS-IS, to build routing tables. Route reflection is a widely adopted technique to tackle BGP scalability in the intra-domain scope, and choosing which routers will play the reflector role and which BGP sessions will be established among reflectors and clients (i.e. the routers which are not elected as reflectors), building an overlay of iBGP sessions, is known as the iBGP overlay design problem. The design of an optimal iBGP overlay is known to be a NP-Hard problem, and we proposed solutions for pure IP networks (i.e. best </span></span>effort traffic<span> forwarding) in our previous work. However, most Internet providers implement their backbones by combining IP routing with MPLS (Multiprotocol Label Switching) for QoS-aware traffic forwarding. MPLS forwarding incorporates traffic engineering and more efficient failover mechanisms; under this traffic forwarding paradigm, the design of traffic-engineered Label Switched Paths<span><span> (LSPs, also referred as MPLS tunnels) shall be combined with the aforementioned iBGP overlay design. The present work introduces a coordinated design of both the iBGP overlay and the IP/MPLS substrates. Our contribution is the proposal of an optimal and resilient topology design for an IP/MPLS Internet backbone, which takes advantage of traffic engineering features to optimize the demands, while guaranteeing iBGP overlay </span>optimality. We present a complete solution for a real world scenario, and we study the scalability of the solution for synthetic topologies, achieving encouraging results.</span></span></span></p></div>","PeriodicalId":54674,"journal":{"name":"Optical Switching and Networking","volume":"42 ","pages":"Article 100635"},"PeriodicalIF":2.2,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.osn.2021.100635","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91593729","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Confidentiality meets protection in elastic optical networks","authors":"G. Savva,&nbsp;K. Manousakis,&nbsp;G. Ellinas","doi":"10.1016/j.osn.2021.100620","DOIUrl":"10.1016/j.osn.2021.100620","url":null,"abstract":"<div><p><span><span><span>This work considers the joint problem of securing confidential demands against </span>eavesdropping attacks and protecting the network against link failures in elastic </span>optical networks<span><span> (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 </span>integer linear programming (ILP) and </span></span>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.</p></div>","PeriodicalId":54674,"journal":{"name":"Optical Switching and Networking","volume":"42 ","pages":"Article 100620"},"PeriodicalIF":2.2,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.osn.2021.100620","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123560536","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Disaster resilience of optical networks: State of the art, challenges, and opportunities","authors":"Jacek Rak ,&nbsp;Rita Girão-Silva ,&nbsp;Teresa Gomes ,&nbsp;Georgios Ellinas ,&nbsp;Burak Kantarci ,&nbsp;Massimo Tornatore","doi":"10.1016/j.osn.2021.100619","DOIUrl":"10.1016/j.osn.2021.100619","url":null,"abstract":"<div><p>For several decades, optical networks, due to their high capacity and long-distance transmission range, have been used as the major communication technology to serve network traffic, especially in the core and metro segments of communication networks. Unfortunately, our society has often experienced how the correct functioning of these critical infrastructures can be substantially hindered by massive failures triggered by natural disasters, weather-related disruptions and malicious human activities.</p><p>In this position paper, we discuss the impact on optical networks of all major classes of disaster events mentioned above, and we overview recent relevant techniques that have been proposed to increase the disaster resilience of optical networks against the various classes of disaster events. We start by presenting some proactive methods to be applied before the occurrence of a disaster. Then we move our focus also on other preparedness methods that can be executed in the (typically short) time frame between the occurrence of an early alert of an incoming disaster and the time a disaster actually hits the network. Finally, we discuss reactive procedures that allow performing post-disaster recovery operations effectively. The analysis of disaster resilience mechanisms provided in this paper covers both wired and optical wireless communication infrastructures and also contains explicit remarks covering the role of emerging technologies (e.g., fixed-mobile convergence in the 5G era and beyond) in disaster resilience.</p></div>","PeriodicalId":54674,"journal":{"name":"Optical Switching and Networking","volume":"42 ","pages":"Article 100619"},"PeriodicalIF":2.2,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.osn.2021.100619","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129469555","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimizing FSO networks resilient to adverse weather conditions by means of enhanced uncertainty sets","authors":"Ilya Kalesnikau ,&nbsp;Marinela Shehaj ,&nbsp;Dritan Nace ,&nbsp;Michał Pióro","doi":"10.1016/j.osn.2021.100628","DOIUrl":"10.1016/j.osn.2021.100628","url":null,"abstract":"<div><p><span>This work deals with dimensioning of wireless mesh networks (WMN) composed of FSO (free space optics) links. Although FSO links realize broadband transmission at low cost, their drawback is sensitivity to adverse weather conditions causing transmission degradation on multiple links. Hence, designing such FSO networks requires an optimization model to find the cheapest configuration of link capacities that will be able to carry an acceptable level of the demanded traffic in all weather states that can be foreseen in network operation. Such a model can be achieved using </span>robust optimization<span> techniques, and for that it is important to find a tractable way of characterizing possible link (capacity) degradation states corresponding to weather conditions not known in advance. In the paper we show how the set of link degradation states may be represented mathematically in a compact and tractable way to be exploited in optimization. To solve this task we will make use of a generalization of a combinatorial problem of finding a minimum hitting set to deduce a compact set approximating a given set of link degradation states, (called uncertainty set). Finally, we provide a mathematical model with respect to a general form of uncertainty sets and illustrate the effectiveness of our model by means of a numerical study.</span></p></div>","PeriodicalId":54674,"journal":{"name":"Optical Switching and Networking","volume":"42 ","pages":"Article 100628"},"PeriodicalIF":2.2,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.osn.2021.100628","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116680752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On survivable energy-efficient and crosstalk-aware routing, spectrum and core allocation schemes for dynamic multiclass traffic in SDM-EONs","authors":"Smita Paira ,&nbsp;Monish Chatterjee ,&nbsp;Uma Bhattacharya","doi":"10.1016/j.osn.2021.100630","DOIUrl":"10.1016/j.osn.2021.100630","url":null,"abstract":"<div><p><span><span>In this paper, we propose the design of a survivable energy-efficient and crosstalk-aware routing, spectrum, and core allocation (RSCA) scheme for online multiclass traffic in both spectral and temporal domains in SDM-EON. Multipath based protection scheme is applied to ensure survivability against single link failure. Advanced reservation (AR) connections being a part of multiclass traffic may withstand some delay in its service from its arrival. Six </span>heuristic algorithms are developed by using three </span>resource allocation schemes<span> associated with both core-classified and non-core classified approaches which are presented in this paper. Extensive simulation experiments are conducted using three well-known network topologies<span> and the performances of the heuristics are evaluated in terms of bandwidth blocking ratio, total energy consumption, and resource occupation rate versus traffic load as well as percentage of AR connections in multiclass traffic.</span></span></p></div>","PeriodicalId":54674,"journal":{"name":"Optical Switching and Networking","volume":"42 ","pages":"Article 100630"},"PeriodicalIF":2.2,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.osn.2021.100630","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116689027","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Joint optimization of primary and backup controller placement and availability link upgrade in SDN networks","authors":"Dorabella Santos ,&nbsp;Teresa Gomes","doi":"10.1016/j.osn.2021.100634","DOIUrl":"10.1016/j.osn.2021.100634","url":null,"abstract":"<div><p><span><span>In Software-Defined Networking (SDN), the control and data planes are decoupled, leading to a more programmable and efficient network management. In this paper, the controller placement problem in SDN is addressed, jointly with the problem of exploring a high-availability tree subgraph, in order to support delay and availability requirements between the switches and the controllers. We consider that each switch connects to a primary and to a backup controller. We formulate the joint optimization model as an </span>integer linear programming model (ILP), and propose a </span>heuristic method when the exact model becomes impractical. Furthermore, we compare two ILP formulations, and we also compare the controller redundancy solutions with those considering path redundancy alone.</p></div>","PeriodicalId":54674,"journal":{"name":"Optical Switching and Networking","volume":"42 ","pages":"Article 100634"},"PeriodicalIF":2.2,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.osn.2021.100634","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125646317","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental validation of an SDN residential network management proposal over a GPON testbed","authors":"Noemi Merayo,&nbsp;David de Pintos,&nbsp;Juan C. Aguado,&nbsp;Ignacio de Miguel,&nbsp;Ramón J. Durán,&nbsp;Patricia Fernández,&nbsp;Rubén M. Lorenzo,&nbsp;Evaristo J. Abril","doi":"10.1016/j.osn.2021.100631","DOIUrl":"10.1016/j.osn.2021.100631","url":null,"abstract":"<div><p>We propose, and experimentally demonstrate, an SDN (Software Defined Networking) new management solution for legacy GPONs (Gigabit Passive Optical Networks), which allows users to dynamically control their residential networks by means of a management application. In this way, users can customize the allocation of resources (and set constraints, if desired) to connected devices in their residential network, fast and efficiently. This real-time customization enables new business models for network operators and service providers. As a proof of concept and to validate the management solution, we demonstrate, in a testbed environment, the operation of a dynamic network scenario where an operator has a business model in which users have a contracted basic bandwidth, but they are allowed to increase it temporarily when using highly demanding services.</p></div>","PeriodicalId":54674,"journal":{"name":"Optical Switching and Networking","volume":"42 ","pages":"Article 100631"},"PeriodicalIF":2.2,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.osn.2021.100631","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131193193","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cascading-failure-resilient interconnection for interdependent power grid - Optical network","authors":"M. Farhan Habib ,&nbsp;Francesco Musumeci ,&nbsp;Massimo Tornatore ,&nbsp;Biswanath Mukherjee","doi":"10.1016/j.osn.2021.100632","DOIUrl":"https://doi.org/10.1016/j.osn.2021.100632","url":null,"abstract":"<div><p><span>The interdependence between communication networks, e.g., an optical backbone network<span><span>, and power grids is a critical issue to take into account when designing and operating both systems. In fact, failures in one network may cause further failures in the other network and vice versa. This is because nodes in power grids (i.e., power generators, loads or interchange nodes) are controlled and managed by telecommunication equipment, which, in turn, rely on the electricity grid for their power supply. Therefore, failures occurring on a limited portion of one network can cascade multiple times between these two networks, and a robust “interdependency network” (i.e., consisting of the interconnections between nodes in the two networks) is needed. This paper investigates the problem of designing a resilient interconnection against interdependent cascading-failures in interdependent power grid - optical networks. We formalize, using an Integer </span>Linear Program, the new problem of </span></span><em>Power Grid - Optical Network Interconnection</em> (<em>PGON-I</em><span><span>), which consists in designing an interconnection between the power grid and the optical network that is resilient to cascading failures, i.e., avoids/reduces cascade. For this problem, we derive analytically upper and lower bounds on the number of interconnection links which ensure resilience against cascading failures initiated from a single node-failure. Starting from the analytical model, we develop a </span>heuristic algorithm to solve large instances of the problem. Our results show that the higher the difference between the number of nodes in the two networks, the more interconnection links are needed to ensure resilience against failures cascade.</span></p></div>","PeriodicalId":54674,"journal":{"name":"Optical Switching and Networking","volume":"42 ","pages":"Article 100632"},"PeriodicalIF":2.2,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91593731","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"RMSA algorithms resilient to multiple node failures in dynamic EONs","authors":"Fábio Barbosa ,&nbsp;Amaro de Sousa ,&nbsp;Agostinho Agra ,&nbsp;Krzysztof Walkowiak ,&nbsp;Róża Goścień","doi":"10.1016/j.osn.2021.100633","DOIUrl":"https://doi.org/10.1016/j.osn.2021.100633","url":null,"abstract":"<div><p>In Elastic Optical Networks (EONs), the way different service demands are supported in the network is ruled by the Routing, Modulation and Spectrum Assignment (RMSA) algorithm, which decides how the spectrum resources of the optical network are assigned to each service demand. In a dynamic EON, demand requests arrive randomly one at a time and the accepted demands last in the network for a random time duration. So, one important goal of the RMSA algorithm is the efficient use of the spectrum resources to maximize the acceptance probability of future demand requests. On the other hand, multiple failure events are becoming a concern to network operators as such events are becoming more frequent in time. In this work, we consider the case of multiple node failure events caused by malicious attacks against network nodes. In order to obtain RMSA algorithms resilient to such events, a path disaster availability metric was recently proposed which takes into account the probability of each path not being disrupted by an attack. This metric was proposed in the offline variant of the RMSA problem where all demands are assumed to be known at the beginning. Here, we exploit the use of the path disaster availability metric in the RMSA of dynamic EONs. In particular, we propose RMSA algorithms combining the path disaster availability metric with spectrum usage metrics in a dynamic way based on the network load level. The aim is that the efficient use of the resources is relaxed for improved resilience to multiple node failures when the EON is lightly loaded, while it becomes the most important goal when the EON becomes heavily loaded. We present simulation results considering a mix of unicast and anycast services in 3 well-known topologies. The results show that the RMSA algorithms combining the path disaster availability metric with spectrum usage metrics are the best trade-off between spectrum usage efficiency and resilience to multiple node failures.</p></div>","PeriodicalId":54674,"journal":{"name":"Optical Switching and Networking","volume":"42 ","pages":"Article 100633"},"PeriodicalIF":2.2,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.osn.2021.100633","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91593730","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improving efficiency of network resources in elastic optical transport network by using in-network cache functions","authors":"Takashi Miyamura ,&nbsp;Akira Misawa","doi":"10.1016/j.osn.2021.100629","DOIUrl":"10.1016/j.osn.2021.100629","url":null,"abstract":"<div><p>We developed a network architecture called information-centric elastic optical transport network (i-CEON) that enables efficient content delivery. Increasing the volume of video traffic consumes network resources, so it is necessary to establish optical transport network architectures suitable for content delivery. For this purpose, we extend existing information-centric networking to be applicable to elastic optical networks. The main focus of this paper is presenting the method in i-CEON of optimizing optical-path routing by effectively using an in-network cache function to efficiently accommodate content traffic. This reduces redundant use of network resources. We formulate the joint optimization problem of elastic optical-path routing and content-replication placement as a mixed integer linear programming problem and also develop a heuristic algorithm. We conducted intensive numerical experiments to demonstrate the effectiveness of our method and confirmed that it reduced network cost by 21% and server load by 32%.</p></div>","PeriodicalId":54674,"journal":{"name":"Optical Switching and Networking","volume":"42 ","pages":"Article 100629"},"PeriodicalIF":2.2,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.osn.2021.100629","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131209896","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}