214 research outputs found
Deliverable DJRA1.2. Solutions and protocols proposal for the network control, management and monitoring in a virtualized network context
This deliverable presents several research proposals for the FEDERICA network, in different subjects, such as monitoring, routing, signalling, resource discovery, and isolation. For each topic one or more possible solutions are elaborated, explaining the background, functioning and the implications of the proposed solutions.This deliverable goes further on the research aspects within FEDERICA. First of all the architecture of the control plane for the FEDERICA infrastructure will be defined. Several possibilities could be implemented, using the basic FEDERICA infrastructure as a starting point. The focus on this document is the intra-domain aspects of the control plane and their properties. Also some inter-domain aspects are addressed. The main objective of this deliverable is to lay great stress on creating and implementing the prototype/tool for the FEDERICA slice-oriented control system using the appropriate framework. This deliverable goes deeply into the definition of the containers between entities and their syntax, preparing this tool for the future implementation of any kind of algorithm related to the control plane, for both to apply UPB policies or to configure it by hand. We opt for an open solution despite the real time limitations that we could have (for instance, opening web services connexions or applying fast recovering mechanisms). The application being developed is the central element in the control plane, and additional features must be added to this application. This control plane, from the functionality point of view, is composed by several procedures that provide a reliable application and that include some mechanisms or algorithms to be able to discover and assign resources to the user. To achieve this, several topics must be researched in order to propose new protocols for the virtual infrastructure. The topics and necessary features covered in this document include resource discovery, resource allocation, signalling, routing, isolation and monitoring. All these topics must be researched in order to find a good solution for the FEDERICA network. Some of these algorithms have started to be analyzed and will be expanded in the next deliverable. Current standardization and existing solutions have been investigated in order to find a good solution for FEDERICA. Resource discovery is an important issue within the FEDERICA network, as manual resource discovery is no option, due to scalability requirement. Furthermore, no standardization exists, so knowledge must be obtained from related work. Ideally, the proposed solutions for these topics should not only be adequate specifically for this infrastructure, but could also be applied to other virtualized networks.Postprint (published version
Multi Protocol Label Switching: Quality of Service, Traffic Engineering application, and Virtual Private Network application
This thesis discusses the QoS feature, Traffic Engineering (TE) application, and Virtual Private Network (VPN) application of the Multi Protocol Label Switching (MPLS) protocol. This thesis concentrates on comparing MPLS with other prominent technologies such as Internet Protocol (IP), Asynchronous Transfer Mode (ATM), and Frame Relay (FR). MPLS combines the flexibility of Internet Protocol (IP) with the connection oriented approach of Asynchronous Transfer Mode (ATM) or Frame Relay (FR). Section 1 lists several advantages MPLS brings over other technologies. Section 2 covers architecture and a brief description of the key components of MPLS. The information provided in Section 2 builds a background to compare MPLS with the other technologies in the rest of the sections. Since it is anticipate that MPLS will be a main core network technology, MPLS is required to work with two currently available QoS architectures: Integrated Service (IntServ) architecture and Differentiated Service (DiffServ) architecture. Even though the MPLS does not introduce a new QoS architecture or enhance the existing QoS architectures, it works seamlessly with both QoS architectures and provides proper QoS support to the customer. Section 3 provides the details of how MPLS supports various functions of the IntServ and DiffServ architectures. TE helps Internet Service Provider (ISP) optimize the use of available resources, minimize the operational costs, and maximize the revenues. MPLS provides efficient TE functions which prove to be superior to IP and ATM/FR. Section 4 discusses how MPLS supports the TE functionality and what makes MPLS superior to other competitive technologies. ATM and FR are still required as a backbone technology in some areas where converting the backbone to IP or MPLS does not make sense or customer demands simply require ATM or FR. In this case, it is important for MPLS to work with ATM and FR. Section 5 highlights the interoperability issues and solutions for MPLS while working in conjunction with ATM and FR. In section 6, various VPN tunnel types are discussed and compared with the MPLS VPN tunnel type. The MPLS VPN tunnel type is concluded as an optimal tunnel approach because it provides security, multiplexing, and the other important features that are reburied by the VPN customer and the ISP. Various MPLS layer 2 and layer 3 VPN solutions are also briefly discussed. In section 7 I conclude with the details of an actual implementation of a layer 3 MPLS VPN solution that works in conjunction with Border Gateway Protocol (BGP)
Deliverable JRA1.1: Evaluation of current network control and management planes for multi-domain network infrastructure
This deliverable includes a compilation and evaluation of available control and management architectures and protocols applicable to a multilayer infrastructure in a multi-domain Virtual Network environment.The scope of this deliverable is mainly focused on the virtualisation of the resources within a network and at processing nodes. The virtualization of the FEDERICA infrastructure allows the provisioning of its available resources to users by means of FEDERICA slices. A slice is seen by the user as a real physical network under his/her domain, however it maps to a logical partition (a virtual instance) of the physical FEDERICA resources. A slice is built to exhibit to the highest degree all the principles applicable to a physical network (isolation, reproducibility, manageability, ...). Currently, there are no standard definitions available for network virtualization or its associated architectures. Therefore, this deliverable proposes the Virtual Network layer architecture and evaluates a set of Management- and Control Planes that can be used for the partitioning and virtualization of the FEDERICA network resources. This evaluation has been performed taking into account an initial set of FEDERICA requirements; a possible extension of the selected tools will be evaluated in future deliverables. The studies described in this deliverable define the virtual architecture of the FEDERICA infrastructure. During this activity, the need has been recognised to establish a new set of basic definitions (taxonomy) for the building blocks that compose the so-called slice, i.e. the virtual network instantiation (which is virtual with regard to the abstracted view made of the building blocks of the FEDERICA infrastructure) and its architectural plane representation. These definitions will be established as a common nomenclature for the FEDERICA project. Other important aspects when defining a new architecture are the user requirements. It is crucial that the resulting architecture fits the demands that users may have. Since this deliverable has been produced at the same time as the contact process with users, made by the project activities related to the Use Case definitions, JRA1 has proposed a set of basic Use Cases to be considered as starting point for its internal studies. When researchers want to experiment with their developments, they need not only network resources on their slices, but also a slice of the processing resources. These processing slice resources are understood as virtual machine instances that users can use to make them behave as software routers or end nodes, on which to download the software protocols or applications they have produced and want to assess in a realistic environment. Hence, this deliverable also studies the APIs of several virtual machine management software products in order to identify which best suits FEDERICA’s needs.Postprint (published version
Auto-bandwidth control in dynamically reconfigured hybrid-SDN MPLS networks
The proposition of this work is based on the steady evolution of bandwidth demanding technology, which currently and more so in future, requires operators to use expensive infrastructure capability smartly to maximise its use in a very competitive environment. In this thesis, a traffic engineering control loop is proposed that dynamically adjusts the bandwidth and route of flows of Multi-Protocol Label Switching (MPLS) tunnels in response to changes in traffic demand. Available bandwidth is shifted to where the demand is, and where the demand requirement has dropped, unused allocated bandwidth is returned to the network. An MPLS network enhanced with Software-defined Networking (SDN) features is implemented. The technology known as hybrid SDN combines the programmability features of SDN with the robust MPLS label switched path features along with traffic engineering enhancements introduced by routing protocols such as Border Gateway Patrol-Traffic Engineering (BGP-TE) and Open Shortest Path First-Traffic Engineering (OSPF-TE). The implemented mixed-integer linear programming formulation using the minimisation of maximum link utilisation and minimum link cost objective functions, combined with the programmability of the hybrid SDN network allows for source to destination demand fluctuations. A key driver to this research is the programmability of the MPLS network, enhanced by the contributions that the SDN controller technology introduced. The centralised view of the network provides the network state information needed to drive the mathematical modelling of the network. The path computation element further enables control of the label switched path's bandwidths, which is adjusted based on current demand and optimisation method used. The hose model is used to specify a range of traffic conditions. The most important benefit of the hose model is the flexibility that is allowed in how the traffic matrix can change if the aggregate traffic demand does not exceed the hose maximum bandwidth specification. To this end, reserved hose bandwidth can now be released to the core network to service demands from other sites
Concepção e implementação de experiências laboratoriais sobre MPLS
Mestrado em Engenharia Electrónica e TelecomunicaçõesO Multiprotocol Label Switching (MPLS) é um mecanismo de
transporte de dados, sob a forma de um protocolo agnóstico, com
grande potencial de crescimento e adequação. Opera na “Camada 2.5”
do modelo OSI e constitui um mecanismo de alto desempenho utilizado
nas redes de núcleo para transportar dados de um nó da rede para outro.
O sucesso do MPLS resulta do facto de permitir que a rede transporte
todos os tipos de dados, desde tráfego IP a tráfego da camada de
ligação de dados, devido ao encapsulamento dos pacotes dos diversos
protocolos, permitindo a criação de “links virtuais” entre nós distantes.
O MPLS pertence à família das “redes de comutação de pacotes”,
sendo os pacotes de dados associados a “etiquetas” que determinam o
seu encaminhamento, sem necessidade de examinar o conteúdo dos
próprios pacotes. Isto permite a criação de circuitos “extremo-aextremo”
através de qualquer tipo de rede de transporte e
independentemente do protocolo de encaminhamento que é utilizado.
O projecto do MPLS considera múltiplas tecnologias no sentido de
prestar um serviço único de transporte de dados, tentando
simultaneamente proporcionar capacidades de engenharia de tráfego e
controlo “out-of-band”, uma característica muito atraente para uma
implementação em grande escala. No fundo, o MPLS é uma forma de
consolidar muitas redes IP dentro de uma única rede.
Dada a importância desta tecnologia, é urgente desenvolver ferramentas
que permitam entender melhor a sua complexidade. O MPLS corre
normalmente nas redes de núcleo dos ISPs. No sentido de tornar o seu
estudo viável, recorreu-se nesta dissertação à emulação para
implementar cenários de complexidade adequada. Existem actualmente
boas ferramentas disponíveis que permitem a recriação em laboratório
de cenários bastante complicados.
Contudo, a exigência computacional da emulação é proporcional à
complexidade do projecto em questão, tornando-se rapidamente
impossível de realizar numa única máquina. A computação distribuída
ou a “Cloud Computing” são actualmente as abordagens mais
adequadas e inovadoras apara a resolução deste problema.
Esta dissertação tem como objectivo criar algumas experiências em
laboratório que evidenciam aspectos relevantes da tecnologia MPLS,
usando para esse efeito um emulador computacional, o Dynamips,
impulsionado por generosas fontes computacionais disponibilizadas
pela Amazon ec2. A utilização destas ferramentas de emulação permite
testar cenários de rede e serviços reais em ambiente controlado,
efectuando o debugging das suas configurações e optimizando o seu
desempenho, antes de os colocar em funcionamento nas redes em
operação.The Multiprotocol Label Switching (MPLS) is a highly scalable and
agnostic protocol to carry network data.
Operating at "Layer 2.5" of the OSI model, MPLS is an highperformance
mechanism that is used at the network backbone for
conveying data from one network node to the next.
The success of MPLS results from the fact that it enables the network to
carry all kinds of traffic, ranging from IP to layer 2 traffic, since it
encapsulates the packets of the diverse network protocols, allowing the
creation of "virtual links" between distant nodes.
MPLS belongs to the family of packet switched networks, where labels
are assigned to data packets that are forwarded based on decisions that
rely only on the label contents, without the need to examine the packets
contents. This allows the creation of end-to-end circuits across any type
of transport medium, using any protocol.
The MPLS design takes multiform transport technologies into account to
provide a unified data-carrying service, attempting simultaneously to
preserve traffic engineering and out-of-band control, a very attractive
characteristic for large-scale deployment. MPLS is the way to
consolidate many IP networks into a single one. Due to this obvious
potential, it is urgent to develop means and tools to better understand its
functioning and complexity.
MPLS normally runs at the backbone of Service Providers networks,
being deployed across an extensive set of expensive equipment. In order
to turn the study of MPLS feasible, emulation was considered as the best
solution. Currently, there are very good available tools to recreate, in a
lab environment, quite complicated scenarios.
However, the computational demand of the emulation is proportional to
the complexity of the project, becoming quickly unfeasible in a single
machine.
Fortunately, distributed computing or Cloud computing are suitable and
novel approaches to solve this computation problem.
So, this work aims to create some lab experiments that can
illustrate/demonstrate relevant aspects of the MPLS technology, using the
Dynamips emulator driven by the computational resources that were
made available by the Amazon ec2 cloud computing facilities. The
utilization of these emulation tools allows testing real networks and
service scenarios in a controlled environment, being able to debug their
configurations and optimize their performance before deploying them in
real operating networks
Segment Routing: a Comprehensive Survey of Research Activities, Standardization Efforts and Implementation Results
Fixed and mobile telecom operators, enterprise network operators and cloud
providers strive to face the challenging demands coming from the evolution of
IP networks (e.g. huge bandwidth requirements, integration of billions of
devices and millions of services in the cloud). Proposed in the early 2010s,
Segment Routing (SR) architecture helps face these challenging demands, and it
is currently being adopted and deployed. SR architecture is based on the
concept of source routing and has interesting scalability properties, as it
dramatically reduces the amount of state information to be configured in the
core nodes to support complex services. SR architecture was first implemented
with the MPLS dataplane and then, quite recently, with the IPv6 dataplane
(SRv6). IPv6 SR architecture (SRv6) has been extended from the simple steering
of packets across nodes to a general network programming approach, making it
very suitable for use cases such as Service Function Chaining and Network
Function Virtualization. In this paper we present a tutorial and a
comprehensive survey on SR technology, analyzing standardization efforts,
patents, research activities and implementation results. We start with an
introduction on the motivations for Segment Routing and an overview of its
evolution and standardization. Then, we provide a tutorial on Segment Routing
technology, with a focus on the novel SRv6 solution. We discuss the
standardization efforts and the patents providing details on the most important
documents and mentioning other ongoing activities. We then thoroughly analyze
research activities according to a taxonomy. We have identified 8 main
categories during our analysis of the current state of play: Monitoring,
Traffic Engineering, Failure Recovery, Centrally Controlled Architectures, Path
Encoding, Network Programming, Performance Evaluation and Miscellaneous...Comment: SUBMITTED TO IEEE COMMUNICATIONS SURVEYS & TUTORIAL
Exploiting the power of multiplicity: a holistic survey of network-layer multipath
The Internet is inherently a multipath network: For an underlying network with only a single path, connecting various nodes would have been debilitatingly fragile. Unfortunately, traditional Internet technologies have been designed around the restrictive assumption of a single working path between a source and a destination. The lack of native multipath support constrains network performance even as the underlying network is richly connected and has redundant multiple paths. Computer networks can exploit the power of multiplicity, through which a diverse collection of paths is resource pooled as a single resource, to unlock the inherent redundancy of the Internet. This opens up a new vista of opportunities, promising increased throughput (through concurrent usage of multiple paths) and increased reliability and fault tolerance (through the use of multiple paths in backup/redundant arrangements). There are many emerging trends in networking that signify that the Internet's future will be multipath, including the use of multipath technology in data center computing; the ready availability of multiple heterogeneous radio interfaces in wireless (such as Wi-Fi and cellular) in wireless devices; ubiquity of mobile devices that are multihomed with heterogeneous access networks; and the development and standardization of multipath transport protocols such as multipath TCP. The aim of this paper is to provide a comprehensive survey of the literature on network-layer multipath solutions. We will present a detailed investigation of two important design issues, namely, the control plane problem of how to compute and select the routes and the data plane problem of how to split the flow on the computed paths. The main contribution of this paper is a systematic articulation of the main design issues in network-layer multipath routing along with a broad-ranging survey of the vast literature on network-layer multipathing. We also highlight open issues and identify directions for future work
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Enhancing performance of conventional computer networks employing selected SDN principles
This thesis was submitted for the award of Doctor of Philosophy and was awarded by Brunel University LondonThis research is related to computer networks. In this thesis, three main issues are addressed which affect the performance of any computer network: congestion, efficient resources utilization and link failure. Those issues are related to each other in many situations. Many approaches have been suggested to deal with those issues as well as many solutions were applied. Despite all the improvements of the technology and the proposed solutions, those issues continue to be a burden on the system’s performance. This effect is related to the increase of the Quality of Service (QoS) requirements in modern networks. The basic idea of this research is evolving the intelligence of a conventional computer network when dealing with those issues by adding some features of the Software Defined Networking (SDN). This adoption upgrades the conventional computer network system to be more dynamic and higher self-organizing when dealing with those issues. This idea is applied on a system represented by a computer network that uses the Open Shortest Path First (OSPF) routing protocol. The first improvement deals with the distribution of Internet Protocol (IP) routed flows. The second improvement deals with tunnel establishment that serves Multi-Protocol Label Switching (MPLS) routed flows and the third improvement deals with bandwidth reservation when applying network restoration represented by Fast Re-route (FRR) mechanism to sooth the effect of link failure in OSPF/MPLS routed network. This idea is also applied on another system that uses the Enhanced Interior Gateway Routing Protocol (EIGRP) to improve the performance of its routing algorithm. Adopting the SDN notion is achieved by adding an intelligent controller to the system and creating a dialog of messages between the controller and the conventional routers. This requires upgrading the routers to respond to the new modified system.Our proposed approaches are presented with simulations of different configurations which produce fine results
Hybrid SDN Evolution: A Comprehensive Survey of the State-of-the-Art
Software-Defined Networking (SDN) is an evolutionary networking paradigm
which has been adopted by large network and cloud providers, among which are
Tech Giants. However, embracing a new and futuristic paradigm as an alternative
to well-established and mature legacy networking paradigm requires a lot of
time along with considerable financial resources and technical expertise.
Consequently, many enterprises can not afford it. A compromise solution then is
a hybrid networking environment (a.k.a. Hybrid SDN (hSDN)) in which SDN
functionalities are leveraged while existing traditional network
infrastructures are acknowledged. Recently, hSDN has been seen as a viable
networking solution for a diverse range of businesses and organizations.
Accordingly, the body of literature on hSDN research has improved remarkably.
On this account, we present this paper as a comprehensive state-of-the-art
survey which expands upon hSDN from many different perspectives
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