Huachun Zhou

An Optimization-Based Scheme for Efficient Virtual Machine Placement

According to the important methodology of convex optimization theory, the energy-efficient and scalability problems of modern data centers are studied. Then a novel virtual machine (VM) placement scheme is proposed for solving these problems in large scale. Firstly, by referring the definition of VM placement fairness and utility function, the basic algorithm of VM placement which fulfills server constraints of physical machines is discussed. Then, we abstract the VM placement as an optimization problem which considers the inherent dependencies and traffic between VMs. By given the structural differences of recently proposed data center architectures, we further investigate a comparative analysis on the impact of the network architectures, server constraints and application dependencies on the potential performance gain of optimization-based VM placement. Comparing with the existing schemes, the performance improvements are illustrated from multiple perspectives, such as reducing the number of physical machines deployment, decreasing communication cost between VMs, improving energy-efficient and scalability of data centers.

Implementation and analysis of proxy MIPv6

Mobile IPv6 (MIPv6) is a host-based mobility support specification which has been approved by the IETF as the standardized solution of global mobility management in IPv6 network for Mobile Node (MN). However, MIPv6 handover procedure results in a large handover delay. To improve its performance, some MIPv6 variants such as Fast Handover for MIPv6 (FMIPv6) and Hierarchical MIPv6 (HMIPv6) were proposed. However, they all require the MN to support the mobility management protocols which increase the difficulty of management and deployment. Recently, IETF NETLMM workgroup published the Proxy Mobile IPv6 (PMIPv6) which is a network-based localized mobility management to provide the mobility support for mobile host without the involvement of the mobility signaling. In this paper, we analyze the singling cost of PMIPv6 and implement it in our test-bed to evaluate its performance. The results show that the PMIPv6 has lower signaling cost and packet delivery cost, and it can improve the handover performance of UDP and TCP than the other mobility management protocols under low-delay networks, as for the wide area networks, it needs to introduce some mechanism like fast handover to further improve its performance. Copyright

A Proxy Mobile IPv6 Based Global Mobility Management Architecture and Protocol

This paper specifies a global mobility management architecture and protocol procedure called GPMIP, which is based on Proxy Mobile IPv6. In GPMIP, mobility management is performed by the network entity rather than individual mobile nodes. The benefit is the elimination of the wireless link data delivery tunnel overhead between a mobile node and the access router. To compare with the well known Hierarchical Mobile IPv6 mobility management protocol, the location update, packet delivery, and total cost functions generated by a mobile node during its average domain residence time are formulated for each protocol based on fluid flow mobility model. Then, the impacts of various system parameters on the cost functions are analyzed. The analytical results indicate that the proposed global mobility management protocol can guarantee lower total costs. Furthermore, a qualitative comparison between GPMIP and some other global management protocols is also investigated.

Proactive Caching for Enhancing User-Side Mobility Support in Named Data Networking

Named Data Networking (NDN) is designed for efficient content dissemination. Several researches are carried out for NDN recently, but the user-side mobility problem is not considered sufficiently. To enhance seamless user-side mobility support in the NDN architecture, we propose a Proactive Caching approach for NDN (PCNDN), which is based on the idea that proactively requests and caches the content items that a user does not receive but were requested before a handover process. Thus, once the user reconnects to the network, it can immediately fetch the content items that were transmitted during its disconnection period. Compared with the original NDN, the analytical and simulation results indicate that the proposed approach has lower handover cost, higher delivery ratio and shorter handover latency. Moreover, the proposed approach prevents unnecessary packet losses on the path towards the old location of the user, alleviates negative effects of user-side mobility on real-time services.

SHIP: Cross-layer mobility management scheme based on Session Initiation Protocol and Host Identity Protocol

In the all-IP wireless networks, mobility management is a crucial issue, and it can be operated at different layers in the traditional Transmission Control Protocol/Internet Protocol (TCP/IP) stack. Session Initiation Protocol (SIP) is an application layer protocol used for the signaling and the mobility management without any modifications of the lower layer protocols, especially in the voice over IP environment. However, since it always gets the lowest priority in the networking model, it will produce the large handoff latency, the packet loss, and the handoff blocking probability. To provide an efficient mobility management, SIP can be combined with other protocols. In this paper, we propose a cross-layer mobility management scheme based on SIP and the Host Identity Protocol (HIP) which is a new protocol designed to provide secure and continuous communications between two nodes by separating the identifier and the locator roles of the traditional IP address. In the proposed scheme, the mobile node and the correspondent node use their host identity tags to establish the session connections, and the mobile nodes uses the HIP location update scheme instead of the SIP location update scheme to update its IP address when it moves to a new subnet. We discuss the proposed scheme’s architecture and the major mobility procedures, including the session setup, the handoff and the location update in this paper. We also develop an analytical model to study the handoff performance of the proposed scheme, the typical SIP, and the hybrid SIP/Mobile IP, respectively. The analytical results demonstrate that the proposed scheme outperforms the typical SIP and the hybrid SIP/Mobile IP in terms of the handoff latency, the packet loss, and the handoff blocking probability.

An authentication method for proxy mobile IPv6 and performance analysis

Proxy mobile IPv6 (PMIPv6) is a network-based mobility protocol where the mobility management signaling is performed by a network entity on behalf of the node requiring mobility itself. To the best of our knowledge, no studies have been conducted in the area of proxy MIPv6 authentication method. This paper proposes an authentication method in proxy MIPv6. In addition to providing access authentication, the proposed authentication method prevents threats such as replay attack and key exposure. Also, we develop analytic models for the authentication latency and cost analysis. Then, the impacts of mobility and traffic parameters on the authentication cost and latency are analyzed, respectively. Copyright

Modeling denial-of-service against pending interest table in named data networking

Named data networking NDN has attracted much attention on the design for next generation Internet architecture. Although it embeds some security primitives in its original architecture, it may suffer from denial-of-service DoS attacks. In this paper, we model one representative type of NDN-specific DoS attacks named DoS against pending interest table PIT, or DoS-PIT, which floods malicious Interests that request nonexistent content to bypass cached content at routers and to exhaust the memory resource for PIT, bringing in severe service degradation. In our proposed analytical model, the closed-form expressions for the DoS probability for users suffering DoS-PIT are derived, while considering several important factors of NDN networks such as PIT size, time-to-live of each PIT entry, popularity of content, and cache size. Moreover, extensive simulation experiments demonstrate the accuracy of the proposed model on evaluating the damage effect of DoS-PIT. In addition, the proposed model can be chosen to guide designing effective countermeasures for DoS-PIT or attacks with similar way to harm NDN by properly setting the values of some parameters e.g., cache size of each NDN router. Copyright

Analysis of Route Optimization Mechanism for Distributed Mobility Management

the mobile data traffic has been extremely expanded for years and will remains the high growth rate in a long term. It is believed that distributed mobility management has been developed to be a new trend of designing mobility management scheme to solve the problem caused by the increasing traffic volume. Based on reviewing the characters of distributed mobility management schemes as a model of “access router distributed but location management centralized”, this paper introduces a distributed mobility management scheme called D-PMIPv6 and its route optimization mechanism. A performance analysis will be given, and numerical results show that the route optimization mechanism this paper proposed has a less signaling cost compared with route optimization mechanism for PMIPv6, but reduces the packets delivery cost as the same as route optimization mechanism for PMIPv6.

Network mobility support in PMIPv6 network

In this paper, we propose a network mobility supporting scheme (N-NEMO) in Proxy Mobile IPv6 (PMIPv6) network, which is an issue still up in the air for the PMIPv6. In the N-NEMO, a tunnel splitting scheme is used to differentiate the inter-Mobility Access Gateway (MAG) and intra-MAG mobility. The performance analysis and comparison between other related schemes show that N-NEMO reduces the signaling cost significantly. Besides, it enhances the efficiency and scalability to provide the comprehensive network mobility in the PMIPv6 context.

D-PMIPv6: A distributed mobility management scheme supported by data and control plane separation

Abstract Over the past few years, modern mobile subscriber devices such as Smartphones, tablets and PDAs have become more and more popular which use network resources in a more aggressive way and last for longer durations involving dramatically increasing traffic volumes. But traditional mobility management schemes have hardly taken this issue into account. Distributed mobility management is considered as a new trend for developing a mobility management scheme to address such an issue. This paper proposes D-PMIPv6, which is to achieve a distributed mobility management scheme supported by data and control plane separation based on PMIPv6. In the architecture of D-PMIPv6, the traditional functional entity Local mobility anchor (LMA) is split into two parts: Control plane LMA and Data plane LMA. We conclude with the three goals of distributed mobility management. With its elaborate design, D-PMIPv6 is proved to achieve these goals. Numerical results show that a single Control plane LMA can hold quite a number of MNs and the handover performance of D-PMIPv6 is acceptable compared to PMIPv6. Meanwhile, D-PMIPv6 can improve the performance in terms of the packet delivery cost compared to other mobility management schemes.