A method for evolving networks by introducing new virtual node/link types using node plug-ins

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.

VHub: Single-stage virtual network mapping through hub location

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.

Virtual network embedding (VNE), which is a significant problem in cloud computing, has gained much attention among many researchers recently. Due to the NP-hardness of VNE, the existing solvers are either inefficient or inaccurate. This paper develops a novel algorithm based on the ant colony system (ACS). To solve the VNE problem, the algorithm structure concentrates on the link mapping from virtual network to substrate network. Particularly, for a specific virtual network request, we first sort the embedding sequence of virtual nodes according to their link resources. Then, ACS is used to embed the virtual nodes onto substrate nodes according the sorted sequence, while the virtual links are mapped via a shortest path strategy for the embedded nodes. For the first time, we propose a link resource heuristic information and incorporate it into the search process of ACS. The link resource heuristic information has two significant effects, one is to make virtual nodes tend to be embedded on the substrate nodes that cost less bandwidth, and the other is to confirm the connectivity of the substrate nodes that embed the virtual nodes. The proposed algorithm improves the optimization performance of VNE when compared with a few existing algorithms, while it substantially reduces the cost of time.

The cloud offers more services across multiple infrastructures and rapidly growing areas of development in medical care. In the cloud, Network virtualization allows multiple isolated virtual networks (VNs) for flexible sharing of network resources. The virtual network mapping in Network virtualization provides the dynamic virtual node and link resources to satisfy the user needs. The major challenges of cloud computing are optimally and resourcefully responds to each user service requests with minimum time. To address these problems in distributed and hybrid cloud environments, Multicriteria Dragonfly based Graph Theory Resource Optimized Virtual Network Mapping (MD-GTROVNM) technique is introduced. The main objective of the MD-GTROVNM technique is to improve the efficiency of virtual network request mapping with less resource utilization. In the MD-GTROVNM technique, Multicriteria Dragonfly based Graph Theory performs both virtual node mapping and link mapping with reasonable resource utilization such as CPU, memory, and bandwidth. In node mapping, the Multicriteria Dragonfly optimization technique is applied to find the optimal physical node among the population that satisfies the resource constraints. The proposed Multicriteria Dragonfly optimization algorithm achieved a more optimal solution for virtual network mapping. The experimental scenario is carried out with various parameters such as mapping efficiency, computation time, Request acceptance ratio and memory consumption with a number of VN requests. The observed results confirm that the MD-GTROVNM technique effectively increases the mapping efficiency, Request acceptance ratio and minimizes the computation time as well as memory consumption when compared to the existing techniques.

With their widespread deployment, the need to provide QoS in virtual networks is being realized. We show that traditional scheduling algorithms like WFQ are incapable of providing a bounded delay service in a virtual network. The problem arises because traffic of a number of sessions sharing a virtual link in a virtual network is aggregated and tunneled through the physical network, which cannot isolate the traffic of well behaved sessions from that of misbehaving sessions. We show that this problem can be solved by regulating output burstiness on virtual links. Using the theory of latency rate servers, we show that latency rate servers with bounded output burstiness, may be used in a virtual network to provide bounded delay service. This gives a method to design a generic class of scheduling algorithms for virtual networks. Finally, we discuss how to integrate best effort and real-time traffic in a virtual network.

In the context of 5G network slicing, in order to solve the problem of low service reliability, a high-reliability virtual network resource allocation algorithm based on service priority is proposed in this paper. The algorithm includes four steps: priority ranking of virtual network request and virtual nodes, reliability ranking of underlying nodes, resource allocation for virtual nodes, and resource allocation for virtual links. The priority ranking of virtual network request and virtual nodes mainly include two processes of ordering the virtual network based on service priority and ordering the virtual node based on centrality. In the step of allocating resources to virtual nodes, the main work is to allocate resources to virtual nodes based on the resources and reliability of the underlying nodes. In the simulation experiment, the algorithm in this paper is compared with the traditional algorithm, which verifies that the algorithm in this paper has achieved good results in terms of key business reliability indicators.

Network virtualization (NV) has widely envisioned as a crucial factor for the success of the future networks by enabling a flexible, cost-effective and on-demand deployments of multiple network service requests on a shared physical infrastructure. The major challenge of NV is to efficiently and effectively embed heterogeneous virtual network requests (VNRs), consisting of a set of virtual nodes connected by virtual links, onto a shared substrate network meeting various stringent resource constraints. Most of the research papers in this field have merely focused on separate virtual node mapping (VNoM) or virtual link mapping (VLiM) with scalable heuristic algorithms. The lack of a coordination between node and link mapping stages results in low acceptance ratio as well as network revenues. In this paper, we propose a new approach based on Genetic Algorithm (GA) that jointly coordinates node and link mappings where the link mapping is relied on a path ranking method. A novel heuristic conciliation mechanism is introduced to handle a possible set of infeasible link mappings during gener-ating virtual embedding solutions in GA's operations. Extensive evaluation results show that our proposed GA-based algorithm outperforms state-of-the-art virtual embedding algorithms in all performance metrics we adopted.

Effective identification of traffic network bottlenecks is a fundamental aspect of preventing traffic congestion and ameliorating traffic network conditions. In this paper, bottlenecks have been analyzed systematically based on traffic equilibrium assignment theory, and we propose a simplified and abstract traffic network method with the groups as virtual nodes and traffic channels between groups as virtual links; based on the virtual traffic network, the model of traffic equilibrium assignment is used to obtain the virtual traffic network’s equilibrium flow. The ratio of virtual road network’s equilibrium flow and its capacity is set as the corresponding parameter, compared with the standard of bottleneck identification to identify the bottleneck. The proposed model is employed in simulating congestion bottleneck identification under different traffic demands. Additionally, we use the traffic network of Nanjing urban districts as a case to verify the feasibility of the method of virtual traffic networks to identify network bottlenecks.

This paper addresses the problem of managing highly dynamic network and service environments, where virtual nodes and virtual links are created and destroyed depending on traffic volumes, service requests, or high-level goals such as reduction in energy consumption. This problem will be one of the main technical challenges to be faced in the evolution towards Future Networks (FN). Emerging paradigms such as Software Defined Networks (SDN) and Network Function Virtualization (NfV) are concrete steps towards infrastructures where network functions and services will be executed as applications in ensembles of virtual machines (VMs) hosted in pervasive standard hardware resources located across a network. The paper argues that in order to manage these virtual infrastructures there is a need to introduce high-level systems orchestration. The paper describes an architecture based on an orchestrater that ensures the automatic placement of the virtual nodes and the allocation of network services on them, supported by a monitoring system that collects and reports on the behaviour of the resources. The orchestrater manages the creation and removal of the virtual nodes, as well as configuring, monitoring, running and stopping software on them. As a proof of these concepts, a distributed orchestrater prototype has been designed, implemented and tested with the results of different placement algorithms presented.

In this work, we study the availability-aware survivable virtual network embedding (A-SVNE) problem in optical interdatacenter networks that use wavelength-division multiplexing. With A-SVNE, we try to satisfy the availability requirement of each virtual component (i.e., a virtual link or a virtual node) in a virtual network. We first analyze the availability of a virtual component based on the availabilities of the substrate link(s) and node(s). Then, we formulate an integer linear programming model for the A-SVNE problem and propose several time-efficient heuristics. Specifically, we design two node mapping strategies: one is sequential selection using efficient weights defined by the availability information, while the other uses auxiliary graphs to transform the problem into a classical problem in graph theory, i.e., the maximum-weight maximum clique. Finally, we use extensive simulations to compare the proposed A-SVNE algorithms with existing ones in terms of the blocking probability, availability gap, and penalty due to service-level agreement violations, and the results indicate that our algorithms perform better.

The Internet of Things (IoT) is the cornerstone of smart applications such as smart buildings, smart factories, home automation, and healthcare automation. These smart applications express their demands in terms of high-level requests. Application requests in service-oriented IoT architectures are translated into a business process (BP) workflow. In this paper, we model such a BP as a virtual network containing a set of virtual nodes and links connected in a specific topology. These virtual nodes represent the requested processing and locations where sensing and/or actuation are needed. The virtual links capture the requested communication requirements between nodes. We introduce a framework, optimized using mixed integer linear programming (MILP), that embeds the BPs from the virtual layer into a lower-level implementation at the IoT physical layer. We formulate the problem of finding the optimal set of IoT nodes and links to embed BPs into the IoT layer considering three objective functions: i) minimizing network and processing power consumption only, ii) minimizing mean traffic latency only, iii) minimizing a weighted combination of power consumption and traffic latency to study the trade-off between minimizing the power consumption and minimizing the traffic latency. We have established, as reference, a scenario where service embedding is performed to meet all the demands with no consideration to power consumption or latency. Compared to this reference scenario, our results indicate that the power savings achieved by our energy efficient embedding scenario is 42% compared with the energy-latency unaware service embedding (ELUSE) reference scenario, while our low latency embedding reduced the traffic latency by an average of 47% compared to the ELUSE scenario. Our combined energy efficient low latency service embedding approach achieved high optimality by jointly realizing 91% of the power and latency reductions obtained under the single objective of minimizing power consumption or latency.

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.

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.

Cloud computing is a novel paradigm which relies on the vision of resource sharing over the Internet. The concept of resource virtualization, i.e. hiding the detail specification of the resources from the end users is the key idea of cloud computing. But the tenants have limited visibility over the network resources. The Network-as-a-Service (NaaS) framework integrates the cloud computing services with direct tenant access to the network infrastructure. The Network virtualization (NV) is such a platform that acts as a mediation layer to provide NaaS to tenants. NV supports the coexistence of multiple virtual networks, which is the collection of virtual nodes and virtual links on the same underlying physical infrastructure. Prior to set up a virtual network in an NV Environment, resource discovery and resource allocation are the primary job. In this chapter, we have discussed on basic NV architecture, surveyed the previous work on the resource allocation along with ongoing research projects on network virtualization.