Dynamic node allocation in Network Virtualization

International audienceNetwork virtualization is a new technology that provides a transparent abstraction of the networking resources. The most important challenge in network virtualization is the allocation of the physical substrate network among the pool of the active virtual networks (VNs). Our work in progress aims at allocating the node resources in a virtualized networking infrastructure. We believe that this allocation should be dynamic to lead to higher performance and better utilization of the physical resources. In this paper, we propose two models for dynamic node allocation for multiple VNs. The first model uses game theory and market-based approach in order to better allocate the physical node. The second one proposes a dynamic weighted round robin (WRR) approach where each VN receives a fraction of the physical node according to an estimation of its current number of waiting packets and its weight. Both models use a distributed approach to minimize the packet delays inside the physical router and to fairly allocate the nodes between different VN

Automated Controllers for Bandwidth Allocation in Network Virtualization

International audienceThe concept of network virtualization was introduced to facilitate flexible service deployment for the future Internet. This recent technology provides a powerful tool to run multiple logical networks on the same physical substrate defined as virtual networks (VNs). Each physical link is split into virtual links and each VN receives a fraction of the available capacity. Bandwidth allocation for multiple VMs aims at sharing the physical links among multiple VNs. It is a critical challenge for both service providers (SPs) and infrastructure providers (InPs). This allocation should take into account the quality of service (QoS) requirements of the flows that are crossing each VN. In this paper, we consider a virtualized network environment where the SP deploys multiple VNs with different links' capacity demands and QoS requirements. Each VN competes with other VNs to receive fractions of physical links managed by multiple InPs. We present a two-layer controller system that adapts to the dynamic change of the workload of each VN. The system uses a prediction-based approach in order to find the optimal request for each VN. The request depends on the estimation of the relationship between the VN performance in terms of packet delays and the actual and past allocations. Then, due to the capacity constraint of the physical link, the system adjusts the offered bandwidth for each of them. Our model offers flexible distributed autonomous control of the bandwidth allocation to maintain the offered QoS to each VN at the desired level in response to the dynamics of the workload. Our mechanism provides an optimum allocation of the physical links by distributing the bandwidth periodically. It also offers the possibility of adjusting the VNs' parameters to take into account the current network behaviour to avoid bottleneck virtual links

Queuing analysis of dynamic resource allocation for virtual routers

International audienceThe most critical issue in network virtualization is the dynamic resource allocation of the physical substrate. There is a need to monitor the running virtual routers in order to allow an adaptive change in the resource allocation. In this paper, we focus on the router data plane virtualization and we explore this issue by presenting a new dynamic allocation approach through queuing theory. We consider the problem where multiple instances of virtual routers (VRs) that have some quality of service (QoS) requirements are sharing different physical resources. We propose a novel router architecture that offers a strong isolation between concurrent VRs and provides a dynamic allocation scheme in order to guarantee the provided QoS to each of them. Our approach aims at providing a higher isolation for the concurrent virtual routers sharing the same infrastructure. We propose a dynamic Weighted round robin (WRR) scheduler for each physical resource and an algorithm for adjusting the weight of each VR in order to reduce the delay of the packet processing and avoid the bottlenecks. We also propose an admission control mechanism that estimates the current load of the physical node and decides either to accept or reject a creation request of a new VR. Simulation results show that the proposed approach achieves good performance in terms of delay minimization inside the virtual router

FlowQoS: QoS for the Rest of Us

International audienceWe describe the architecture of FlowQoS, a system that makes it easier for users in home broadband access networks to configure quality of service based on applications and devices, as opposed to obscure, low-level parameters. The central tenet of FlowQoS's design is control logic that performs application identification and uses flow-table rules to forward traffic through the appropriate rate shapers on a home router. The architecture has two components: a flow classifier, which maps application traffic to the appropriate parts of flow space; and an SDN-based rate shaper, which shapes application traffic by forwarding it through the appropriate shaped virtual links in the home gateway. This paper describes the high-level architecture of FlowQoS, as well as our current implementation

FlowQoS: Per-Flow Quality of Service for Broadband Access Networks

Research areas: Computer NetworksIn broadband access networks, one application may compete for the bandwidth of other applications, thus degrading overall performance. One solution to this problem is to allocate bandwidth to competing flows based on the application type at the gateway of the home network. Unfortunately, application-based quality of service (QoS) on a home network gateway faces significant constraints, as commodity home routers are not typically powerful enough to perform application classification, and many home users are not savvy enough to configure QoS parameters. This paper describes FlowQoS, an SDN-based approach for application-based bandwidth allocation where users can allocate upstream and downstream bandwidths for different applications at a high level, offloading application identification to an SDN controller that dynamically installs traffic shaping rules for application flows. FlowQoS has two modules: a flow classifier and an SDNbased rate limiter. We design a custom DNS-based classifier to identify different applications that run over common web ports; a second classifier performs lightweight packet inspection to classify non-HTTP traffic flows. We implement FlowQoS on OpenWrt and demonstrate that it can improve the performance of both adaptive video streaming and VoIP in the presence of active competing traffic

Molecular signatures of T-cell inhibition in HIV-1 infection

Cellular immune responses play a crucial role in the control of viral replication in HIV-infected individuals. However, the virus succeeds in exploiting the immune system to its advantage and therefore, the host ultimately fails to control the virus leading to development of terminal AIDS. The virus adopts numerous evasion mechanisms to hijack the host immune system. We and others recently described the expression of inhibitory molecules on T cells as a contributing factor for suboptimal T-cell responses in HIV infection both in vitro and in vivo. The expression of these molecules that negatively impacts the normal functions of the host immune armory and the underlying signaling pathways associated with their enhanced expression need to be discussed. Targets to restrain the expression of these molecular markers of immune inhibition is likely to contribute to development of therapeutic interventions that augment the functionality of host immune cells leading to improved immune control of HIV infection. In this review, we focus on the functions of inhibitory molecules that are expressed or secreted following HIV infection such as BTLA, CTLA-4, CD160, IDO, KLRG1, LAG-3, LILRB1, PD-1, TRAIL, TIM-3, and regulatory cytokines, and highlight their significance in immune inhibition. We also highlight the ensemble of transcriptional factors such as BATF, BLIMP-1/PRDM1, FoxP3, DTX1 and molecular pathways that facilitate the recruitment and differentiation of suppressor T cells in response to HIV infection.Funding Agencies|University of Malaya Research Grant (UMRG) of the Health and Translational Medicine Research Cluster, University of Malaya, Kuala Lumpur|RG448-12HTM|Swedish Research Council||Swedish Physicians against AIDS Research Foundation||Swedish International Development Cooperation Agency||SIDA SARC||VINNMER for Vinnova||Linkping University Hospital Research Fund||CALF||Swedish Society of Medicine||Ministry of Higher Education Malaysia, High Impact Research Grant|HIRGA E000001-20001||AI52731|</p