Scheduling algorithms for bounded delay service in virtual networks

Aiming at the virtual network embedding problem under dynamic service request, Service Request Aware-based Dynamic Virtual Network Embedding (SRAD) algorithm is proposed. We first present virtual network embedding model, and then define virtual network construction cost according to the dynamic characteristic of service request. Our goal is to find the optimal reconfiguration policies by awaring service request type and changing trends, which can minimize the overall construction cost using substrate resource. Experimental results show that the proposed algorithm satisfies the service request, achieves higher success ratio and gains higher revenue/cost ratio for substrate network comparing with the existing algorithms.

Network virtualization is seen as a key networking paradigm for building diverse network services and architectures over a shared network infrastructure. Assigning network resources to virtual links and, more generally to virtual network topologies, efficiently and on-demand is one of the most challenging components of any network virtualization solution. This paper addresses the problem of on-line resource allocation of multiple virtual links on a Software Defined Network (SDN) infrastructure. The application context that is targeted is primarily the online provisioning of virtual overlay networks even if it can be broadened to address more general virtual networks. Considering an SDN physical infrastructure allows a complete freedom in choosing the optimal physical paths and the associated resources that support the virtual links with no interference from any other network function (such as routing). However, for the time being, forwarding in an SDN network is resource consuming with a noticeable impact on the size of the flow tables. Hence, forwarding (i.e. switching) resources should be carefully considered by the network resource allocation algorithm. This paper proposes a novel Integer-Linear formulation of the above cited problem by taking into account: (1) point-to-point as well as point-to-multipoint virtual links, each with an associated bandwidth requirement and a maximum transfer delay requirement, (2) two types of network resources, namely network links' bandwidth and nodes' switching resources, and (3) optionally, path splitting which allows a virtual link to be established on multiple physical paths. We report preliminary experimental results on a real network topology in an overloaded scenario (bandwidth requests largely exceed network capacity); they show that our algorithm outperforms shortest path heuristics with a gain on the admission rate (of virtual links requests) that ranges from 5 to 15% (compared to the most efficient heuristic) and with a computation time less than a few seconds.

Network virtualization (NV) provides a feasible mechanism for operating numerous diverse virtual networks concurrently on a shared physical infrastructure network. The key issue in NV is virtual network embedding (VNE), which efficiently and effectively maps virtualized networks (VNs) with multiple resource needs for nodes and links to the underlying physical network with limited resources. A multiple topological attributes (MTA) based embedding algorithm is proposed to address the issue of providing different virtual request ser-vices delivered in a wireless network environment, leading to an unstable utilization of physical network resources and a low access rate for subsequent requests. It is emphasized that machine learning (ML) should be integrated into the process of network slicing in order to properly classify the received wireless virtual request. In this work, virtual request services are categorized automatically using support vector machine (SVM), and resources are allocated accordingly. The proposed technique organizes nodes in the embedding process according to their priority based on multiple topological properties of virtual and physical networks. According to the findings of the simulations, the SVM-MTA algorithm enhances both the acceptance rate and the resource efficiency of the network.

Virtual private networks (VPN) and link sharing are cost-effective ways of realizing corporate intranets. Corporate intranets will increasingly have to provide integrated services for voice and multimedia traffic. Although packet scheduling algorithms can be used to implement integrated services in link sharing and virtual private networks, their statistical multiplexing gains are limited. We propose a new scheme called stochastic fair sharing (SFS) to carry out fair link sharing and fair sharing among virtual leased links (VLL). In the link sharing environment, capacities allocated to different classes are adjusted dynamically as sessions arrive (or depart). The SFS admission control algorithm decides which sessions to accept and which to reject depending upon the current utilizations and provisioned capacities of the classes. SFS gives protection to classes with low session arrival rate against classes with high session arrival rates by ensuring them a low blocking probability. In the case of multi-hop VLL, capacity resizing requests are sent in the service providers's network which are admission-controlled using SFS. Our simulations indicate that using SFS, the equivalent capacity of virtual links converge to their max-min fair capacity, with a fairness index of 0.97 in extreme situations. The average signaling load of the protocol was found to be reasonable. The scheme is simple to implement, efficient, and robust. The potential applications of SFS are fair and efficient resource sharing in telecommunication networks, ATM networks, virtual private networks (VPN) and integrated services or differentiated services-based IP networks.

VHub: Single-stage virtual network mapping through hub location

Recently, technology of cloud computing has been rapidly developed, and it is expected to apply for various network services. Virtual technology is a part of significant technology which has been contributed for the development of cloud computing. Various virtual technologies such as virtual OS and VDE become very important for server and network management in these days. Furthermore, such a virtual technology becomes possible to provide efficient resource management or QoS with virtual network configuration. Thus, it will be important for network construction to provide hardware and software service in near future. Autonomous network configuration in virtual layer is one of such a service. Not only network configuration is constructed in physical layer, but also it should be constructed in virtual layer for providing optimal resource and QoS management. In this paper, Overlay Cloud Computing Service is proposed, and it is consisted of virtual autonomous network configuration in cloud computing service including various server and network services. In our proposal methods, first of all, there are various kinds of user policy such as eco mode, high power mode, and secure mode. Then, virtual network and server configuration is automatically held in virtual layer with the mode setting and hardware configuration. Besides, with observation values of network and server condition, virtual configuration is changed optimally. In this optimal configuration changes, Kalman filter is used for the calculation of network and server condition. Then, with the results of calculation, virtual network topology is changed. In this paper, first, introduction and cloud computing service is discussed. Then, our proposed Overlay Cloud Computing Service by autonomous network configuration is introduced. In the chapter, optimal control method by Kalman filter with observed values is also introduced. Finally, conclusion and future study is discussed.

When the traditional heterogeneous multi-core scheduling algorithm performs tasks with high resource density, a large amount of idle time often occurs on the processor core. Therefore, based on the environment of heterogeneous multi-core processors, this paper studies the static heuristic table scheduling algorithm, and proposes an optimization approach for the problem of single priority assignment and too simple task assignment. We design optimization in the static heuristic scheduling algorithm list generation phase and task allocation phase, and propose a hybrid task allocation method with three strategies to improve the standby time utilization of processor core. Then, DVFS technology is used to optimize the scheduling results, so that the task can run with lower energy consumption without increasing makespan. Finally, the new algorithm is compared with three traditional scheduling algorithms through design experiments, and it is proved that the new algorithm has better performance when executing more tasks.

Network virtualization is a core technology in next-generation networks to overcome the ossification problem that is observed in the current Internet. The key idea of network virtualization is to split physical network resources into multiple logical networks, each supporting different network services and functionalities. One of the key challenges for virtual network infrastructure providers is to efficiently allocate network resources based on virtual network requests, which is referred to as the virtual network mapping problem. While several algorithms have been proposed previously to solve this mapping problem, their effectiveness is limited since virtual requests specify the internal topology of the virtual network. In this paper, we argue that such internal topologies lead to unnecessary constraints and less efficient solutions. Instead, we propose an alternate formulation of the problem that represents virtual network requests as traffic matrices. We provide a solutions to solving this traffic-matrix-based mapping problem using a mixed integer programming formulation. Our simulation results show that our approach can map significantly more virtual network requests on a physical network infrastructure than previous mapping algorithms and thus improves the efficient use of networking resources in virtual networks.

Network virtualization has been put forward as a promising way to run multiple virtual networks (VNs) simultaneously on a shared physical network. As single physical failure can bring down the services of multiple VNs, the problem of efficiently mapping VNs to a physical network while guaranteeing the survivability of VNs has become an increasingly important issue. In this paper, we propose a novel survivable multi-domain VN embedding approach against single link failure. Specifically, we first investigate the visibility of VN Providers on physical network resources and topology for VN splitting. Then we present a framework for multi-domain VN embedding that comprises a set of operations. Moreover, we enhance the survivability of VNs by guaranteeing the sustaining connectivity for VNs against single link failure, and formulate the survivable inter-domain embedding problem as an integer linear programming. Simulation results demonstrate the effectiveness and efficiency of our algorithm.

Virtualization is the fundamental attribute of next generation network. Embedding customized virtual networks (VNs) onto the underlying physical network (PN) is the core issue in virtualization research. This issue is virtual network embedding (VNE). Since the issue inception, multiple mapping algorithms have been studied. However, prior mapping algorithms are mostly static. Existing dynamic mapping algorithms just focus on accepting as many VNs as possible. No existing dynamic algorithm considers optimizing the quality of service (QoS) performance of each accepted VN. On these backgrounds, we jointly investigate the dynamic VN embedding and optimize the QoS performance of each accepted VN. A dynamic heuristic algorithm is proposed in order to be evaluated in continuous time. When one VN service is requested, the VN will be mapped by the dynamic heuristic algorithm. If the QoS demand of the VN is not guaranteed, the re-embedding scheme of the heuristic algorithm will be driven. Certain virtual elements of the VN will be re-embedded. The dynamic embedding algorithm ensures flexible VN assignment and improves the physical resource utilization. Finally, simulation results are illustrated in order to validate the strength of our proposed dynamic algorithm. For instance, VN acceptance ratio of our dynamic heuristic algorithm improves at least 13%.

Network virtualization (NV) allows multiple heterogeneous virtual networks (VNs) to coexist and operate over the same physical network (PN) infrastructures. Some of the benefits of this advancement include flexibility in VN topologies, heterogeneity in VN technologies, and modularity of network operations. However, there are a few areas, such as resource allocation and economics, which challenge the implementation of NV. In this paper, we first introduce some NV parameters that influence the resource allocation and economics of an NV system. Next, we formulate an economic model for NV using the prey-predator food chain model. This model takes into account the dynamics in an NV system, such as the service, payoff, failure, and competition rates within each VN and PN. The solution point to this model represents the resource strategy of the service provider (SP) given the number of users trying to use its VN, as well as the resource strategy of the infrastructure provider (InP) given the strategy of the VN leasing its PN. In addition, we establish economic models that relate the capacities of the end users, the SP, and the InP. Finally, we provided simulations that show how the prey-predator food chain model fits well on an NV system.

In the software defined optical network (SDON) for virtual network services, there still exists unbalanced traffic load distribution in SDON. The traditional load balance mapping method exists in the problem of heavy load of key nodes in optical network and low request acceptance rate of virtual network. In this paper, a virtual mapping method of optical network based on topology awareness is proposed. When the controller of optical network is defined by software, the topology information of nodes and links in the whole network is acquired, and the relative balance weight of each node and link is calculated by combining the connectivity factor. When the virtual network service arrives, the optical network is based on the bandwidth of virtual network service the method of node mapping and link mapping is needed to improve the success rate and balance of virtual network mapping, and avoid the local overload of optical network resources.

The design, management, and operation of network infrastructure have evolved during the last few years, leveraging on innovative technologies and architectures. With such a huge trend, due to the flexibility and significant economic potential of these technologies, software-defined networking (SDN) and network functions virtualization (NFV) are emerging as the most indispensable key catalysers. SDN/NFV enhancing the infrastructure agility, thus network operators and service providers are able to program their own network functions (e.g., gateways, routers, load balancers) on vendor-independent hardware substrate. One of the most important considerations in NFV deployment is how to allocate the virtual resources that are needed to provide flexible virtual network services in an NFV-based network infrastructure. Thus, the most important prerequisite for NFV deployment is achieved fast, scalable and dynamic composition and allocation of networks functions (NFs) to implement network services (NSs). We have proposed a revised RA algorithm that integrates embedding and scheduling of virtual network functions (VNFs) simultaneously. In this paper, performance evaluation of the revised RA algorithm is performed and the proposed algorithm is applied more effectively in NFV environment where the demand for resources is flexible and concentrated.

Network virtualization is a key enabling technology for “Infrastructure as a Service” provisioning, increasing the flexibility and cost savings offered to customers. By extending the concept of server virtualization to the network infrastructure, the allocation of different, independent virtual networks over a single physical network is carried out on demand. A fundamental challenge in network virtualization systems is to choose which physical nodes and links to use for hosting virtual networks in the physical infrastructure, known as the “virtual network allocation” problem. All virtual network allocation proposals on elastic optical networks assume a centralized operation, deploying a single node with access to the network state global information and assigning resources accordingly. However, such configuration might exhibit the inherent problems of centralized systems: survivability and scalability. In this paper, we present a distributed protocol for resource discovery, mapping, and allocation of network virtualization systems. The distributed protocol is generic enough as to be used with different substrate networks. However, in this paper, it has been adapted to work over an elastic optical network infrastructure, where further considerations regarding the spectrum continuity and contiguity constraints must also be taken into account. The distributed protocol is based on the concept of alliances: upon the arrival of a virtual network request, agents located in the physical network nodes compete to form the first alliance able to host the virtual network. Because the first alliances to be formed are also the ones composed by nearby nodes, a good network resource usage is achieved. The feasibility of the distributed protocol was studied by evaluating its ability to successfully establish virtual networks within acceptable time and with low bandwidth consumption from the coordination messages.

In this paper, we propose a new preventive reliable virtual network embedding algorithm denoted by PR-VNE within the Cloud's backbone network. The proposal does not allocate any backup resources and takes into consideration the ageing of the hardware backbone network. The main objective is to maximise the number of hosted virtual networks while minimising the rate of crashed virtual networks impacted by physical (i.e., routers or links) failures. The problem is a multi-objective non-linear optimisation and classified as NP-hard. To overcome its complexity, PR-VNE is based on the artificial bee colony metaheuristic. Moreover, it makes use of a multi commodity flow algorithm in order to maximise the load balancing of bandwidth usage within the physical network. Based on extensive simulations, the performance obtained is better than the related strategies found in literature in terms of reject and blackout rates of virtual networks.