Virtualized Data Center Networks Research Articles

A survey and taxonomy on virtual data center embedding

Data center network virtualization is being considered as a promising technology to provide a performance guarantee for cloud computing applications. One important problem in data center network virtualization technology is virtual data center (VDC) embedding, which handles the physical resource allocation to virtual nodes (virtual switches and virtual servers) and virtual links of a VDC. When node and link constraints (including CPU, memory, storage and network bandwidth) are both taken into account, the VDC embedding (VDCE) problem becomes NP-hard. The VDCE is so crucial that took wide consideration since it directly affects the execution, resource use and power consumption of data centers. To the best of our knowledge, there is no published work that precisely outlines open challenges connected with VDCE problem including all of its variants. On this point, this work tries to articulate this problem and bring research taxonomy for succinct classification of existing works. Moreover, we summarize the possible techniques already presented in the literature and we establish a classification based on a taxonomy study. At the end, we examine the limitations of existing solutions and identify the related open challenges.

Resource availability–aware adaptive provisioning of virtual data center networks

SummaryOptimal provisioning of virtual networks with varying topologies on their physical counterpart is a major challenge in cloud data centers. Embedding the virtual network on the shared physical infrastructure poses a multitude of challenges to the infrastructure provider. This paper proposes a hybrid approach which adapts to the availability and fragmentation level of residual resources for near‐optimal mapping of multiple virtual data center networks on a substrate data center network. The proposed technique uses coordinated static and dynamic embedding phases, adaptively, to maximize the density of embedding which increases the revenue of the cloud service provider. Also, it judiciously modifies the existing mappings for efficient utilization of resources. Empirical results show that the proposed hybrid approach can attain ∼10% higher acceptance ratio compared with the existing exact and heuristic techniques in the literature. With the proposed mixed integer programming model for static embedding, the average path length is reduced by 20% compared with the existing techniques.

Performance analysis of modified BCube topologies for virtualized data center networks

Network virtualization enables the computing networks and data center (DC) providers to manage their networking resources in a flexible manner using software running on physical computers. Thus, using DC topology with high flexibility to the required service-level changes is very important to this purpose. In this paper, we address the existing issues with the classic DC network topology in virtualized DC networks and investigate the performance of a set of modified BCube topologies with the capability of providing dynamic structures according to the bandwidth requirement in a virtual DC network. In particular, we propose three main approaches to modify the structure of a classic BCube topology as a topology benchmark and investigate their associated structural features and maximum achievable interconnected bandwidth for different routing scenarios. Finally, we run an extensive simulation program to check the performance of the proposed modified topologies in a simulation environment which considers the failure analysis and also traffic congestion. Our simulation experiments, which are consistent to our design goals, show the efficiency of the proposed modified topologies comparing to the classic BCube in terms of bandwidth availability and failure resiliency.

Implementation and Evaluation of VXLAN Gateway-based Data Center Network Virtualization

Implementation and Evaluation of VXLAN Gateway-based Data Center Network Virtualization

SDN-Enabled OPS With QoS Guarantee for Reconfigurable Virtual Data Center Networks

Optical packet switching (OPS) can enhance the performance of data center networks (DCNs) by providing fast and large-capacity switching capability. Benefiting from the software-defined networking (SDN) control plane, which could update the look-up-table (LUT) of the OPS, virtual DCNs can be flexibly created and reconfigured. In this work, we have implemented and assessed an SDN-based control framework for an OPS node, where the OpenFlow protocol has been extended in support of the OPS switching paradigm. Application flows are switched by the OPS at submicrosecond hardware speed, decoupled from the slower (millisecond timescale) SDN control operation. By the DCN infrastructure provider, the virtual networks become directly programmable with the abstraction of the underlying OPS node. Experimental results validate the successful setup of virtual network slices for intra-data center interconnect and quality of service (QoS) guarantee for high-priority application flows. Data plane resources are efficiently shared by exploiting statistical multiplexing. In addition, the capability of exposing per-port OPS traffic statistics information to the SDN controller enables the implementation and experimental validation of load balancing algorithms to improve the QoS performance.

SPA: Smart Placement Approach for Cloud-service Datacenter Networks

Abstract Business disciplines expand rapidly, so does the tendency to rely on computer applications and its varying services to support such expansion. Often, this is achieved through introducing physical network infrastructures that provide the appropriate environ- ments to run such applications. The required services change rapidly, and accordingly its resource requirements. In most cases, this may require building new physical networks which could lead to low utilization rates and high service-costs. A promising ap- proach that is becoming increasingly popular to overcome such a problem is known as Virtual Datacenter Networks (VDNs). These VDNs are usually hosted over physical networks; overlaying its resources to gain the dynamic required services. Cloud-service Datacenter Networks (CDNs) can provide such a service under a delivery model that is called Infrastructure as a Service (IaaS). In this paper, we present a Smart Placement Approach (SPA) that provides for smart placement maps of VDNs over CDNs. In this, we point out that choosing the placement maps for such VDNs should satisfy its requirements while: maintaining load-balancing over the hosting CDNs, guaranteeing its Quality of Service (QoS) levels, and assuring low placement costs.

A TRILL-based multi-tenant data center network

To achieve an efficient ‘Infrastructure as a Service’ (IaaS) service, virtualized data centers have to provide large-scale multi-tenancy services and to meet new requirements in terms of efficiency and availability. The main limitation of current network architectures mainly comes from inadequate design standards, such as those for Ethernet Bridging (802.1D) and Virtual LAN (802.1Q), which were not designed to handle large numbers of tenants and the resulting traffic volumes.In this paper, we present a TRILL based multi-tenant network architecture for virtualized data center networks. Through the TRILL protocol, this architecture achieves the best of both layers (bridging and routing), thus building a large-scale layer-2 network while ensuring scalability, efficiency, fault-tolerance and simplified management. In addition, this architecture integrates the VNT (Virtual Network over TRILL) solution, enabling the creation of large numbers of logical networks within a virtualized data center. The complete implementation of our solution is currently deployed and running in the GANDI public cloud infrastructure.Experimental evaluations show that VNT is able to support several hundreds of switches, thousands of physical nodes, and hundreds of thousands of tenants with only negligible overhead, all with very minimal configuration which may be completely automated. VNT additionally permits backward compatibility with both traditional layer-2 equipment as well as newer hardware supporting TRILL.

Data Center Network Virtualization: A Survey

With the growth of data volumes and variety of Internet applications, data centers (DCs) have become an efficient and promising infrastructure for supporting data storage, and providing the platform for the deployment of diversified network services and applications (e.g., video streaming, cloud computing). These applications and services often impose multifarious resource demands (storage, compute power, bandwidth, latency) on the underlying infrastructure. Existing data center architectures lack the flexibility to effectively support these applications, which results in poor support of QoS, deployability, manageability, and defence against security attacks. Data center network virtualization is a promising solution to address these problems. Virtualized data centers are envisioned to provide better management flexibility, lower cost, scalability, better resources utilization, and energy efficiency. In this paper, we present a survey of the current state-of-the-art in data center networks virtualization, and provide a detailed comparison of the surveyed proposals. We discuss the key research challenges for future research and point out some potential directions for tackling the problems related to data center design.

Towards full network virtualization in horizontal IaaS federation: security issues

Horizontal IaaS federation exploits datacenter for federation of IaaS provider by supplying virtual nodes (e.g. virtual machines, virtual switches, and virtual routers) and virtual links. Today's datacenters for cloud computing do not supply full network virtualization in terms of user-level network management and user-agreed network topology. The datacenters lack the basic security services required for the collocation of tenants' virtual networks. The network virtualization research projects from academia and industry support full network virtualization but lack the basic security services required for the collocation of tenants' virtual networks. This paper investigates the security issues in four areas namely, (a) monolithic IaaS cloud, (b) network virtualization research projects, (c) datacenter network virtualization and (d) virtual resources to incorporate full network virtualization environment in horizontal IaaS federation. Further, it presents the security related qualitative comparisons of datacenters, network virtualization research projects and virtual resources to incorporate full network virtualization in horizontal IaaS federation.

Effective Security Architecture for Virtualized Data Center Networks

This work presents a candidate scheme for effective security policy that defines the requirements that will facilitate protection of network resources from internal and external security threats. Also, it ensures data privacy and integrity in a virtualized data center network (VDCN). An integration of Open Flow Software Defined Networking (OFSDN) with VLAN Virtual Server Security (VVSS) architecture is presented to address distinct security issues in virtualized data centers. The OFSDN with VVSS is proposed to create a more secured protection and maintain compliance integrity of servers and applications in the DCN. This proposal though still on the prototype phase, calls for community driven responses.