OSA-based service platform for all-IPv6 network environments

The use of IP (Internet protocol) technology in the information and communications industry constitutes a major global trend. A highly efficient service architecture, enabling technologies and advanced applications are essential to rapid multimedia services in an all-IPv6 network environment. This work presents an all-IPv6 service platform based on open service architecture (OSA) to support a set of standard interfaces and applications. The all-IPv6 network environment was integrated using a network-processor-based IPv4/IPv6 translator and a mobile router (MR) supported IPv6 network mobility. The feasibility of the open service platform for all-IPv6 network environments and of the designed application programming interfaces was examined using three applications: e-commerce, video-on-demand, and on-line gaming. The performance analysis indicates that the system throughput increased from 10.5 to 60.5 Mb/s as the number of users increased from 1 to 80; the mean response time increased from approximately 1 to 10.5 ms, and the delay time increased from 0.1 to 1 ms.     

Migration cost optimization for service provider legacy network migration to software-defined IPv6 network

This paper studies a problem for seamless migration of legacy networks of Internet service providers to a software-defined networking (SDN)-based architecture along with the transition to the full adoption of the Internet protocol version 6 (IPv6) connectivity. Migration of currently running legacy IPv4 networks into such new approaches requires either upgrades or replacement of existing networking devices and technologies that are actively operating. The joint migration to SDN and IPv6 network is considered to be vital in terms of migration cost optimization, skilled human resource management, and other critical factors. In this work, we first present the approaches of SDN and IPv6 migration in service providers' networks. Then, we present the common concerns of IPv6 and SDN migration with joint transition strategies so that the cost associated with joint migration is minimized to lower than that of the individual migration. For the incremental adoption of software-defined IPv6 (SoDIP6) network with optimum migration cost, a greedy algorithm is proposed based on optimal path and the customer priority. Simulation and empirical analysis show that a unified transition planning to SoDIP6 network results in lower migration cost.     

Scalable broadcast with network coding in heterogeneous networks

This article studies the scalable broadcast scheme realized with the joint application of layered source coding,unequal error protection(UEP)and random network coding from the theoretical point of view.The success probability for any non-source node in a heterogeneous network to recover the most important layers of the source data is deduced.This probability proves that in this broadcast scheme every non-source node with enough capacity can always recover the source data partially or entirely as long as the finite field size is sufficiently large.Furthermore,a special construction for the local encoding kernel at the source node is proposed.With this special construction,an increased success probability for partial decoding at any non-source node is achieved,i.e.,the partial decodability offered by the scalable broadcast scheme is improved.     

Scalable optical switch with internal fiber network

We present architecture of a large dynamic optical packet/burst switch comprising a number of smaller switching fabrics that are interconnected by internal fiber links. The switching fabrics are based on the broadcast-and-select architecture, while the internal interconnection network is a full mesh. An extensive performance study has been performed and results regarding scalability, packet/burst loss rate and achievable throughput for four scheduling algorithms are shown.     

Dynamic service migration strategy based on MDP model with multiple parameter in vehicular edge network

To handle with the service interruption caused by vehicles’ mobility and limited service coverage of edge servers,a dynamic service migration algorithm based on multi-parameters Markov decision process (MDP) model was put forward for vehicular edge network,which was called as dynamic service migration algorithm based on multiple parameter (DSMMP).Combining delay,bandwidth,server capacity with vehicle motion information,DSMMP constructed a multi-parameters MDP revenue function to remedy the deficiency of distance-based schemes.By using vehicle motion and delay constraints,a candidate server set with several candidate servers was defined,and migration decision through long-term Bellman revenue values was made.In order to improve the dynamic adaptability of the proposed algorithm,the weight values were calculated and updated by leveraging historical information.Simulation results show that our strategy has a good performance in terms of delay,packet loss ratio and service migration times.     

QoS-aware service composition and adaptation in autonomic communication

Advents in network technology and distributed system design have propelled network communication service beyond best effort data delivery. With the rising complexity of network infrastructures and the need for on-demand provisioning operations, a high degree of self-sufficiency and automation is required in the network service infrastructure. Guided by the autonomic communication principle, this paper first presents an autonomic service provisioning framework for establishing quality-of-service (QoS)-assured end-to-end communication paths across administratively independent domains. Through graph abstraction, we show that the domain composition and adaptation problem could be reduced to the classic k-multiconstrained optimal path (MCOP) problem. In analyzing existing k-MCOP solutions, we show their inefficiencies when applied to the service provisioning context and establish a number of new domain composition and adaptation algorithms. These new algorithms are designed for the self-configuration, self-optimization, and self-adaptation of end-to-end network communications and can provide hard QoS guarantees over domains with relative QoS differentiations. Through in-depth experimentations, we compare the performance of our algorithms with classic k-MCOP solutions and demonstrate the effectiveness of our approach.     

Lightweight autonomic dissemination of entertainment services in widescale wireless environments

The spread of wireless portable devices is opening new market opportunities to provide entertainment services to a growing number of potential users. A notable deployment scenario is represented by limited spatial regions, such as stadiums, railway stations, and airports, with a high number of simultaneously present mobile wireless peers (dense MANETs). The provisioning of entertainment services (e.g., the distribution of news, movie trailers, songs, and game components) in dense MANETs is a challenging task, hard to achieve in a scalable way with traditional static network infrastructures. We propose lightweight autonomic dissemination of entertainment services that exploits impromptu collaborations among mobile wireless peers to replicate resources in an efficient and lazily consistent way. In particular, we have developed the REDMAN middleware to manage, retrieve, and disseminate replicas of data/service components transparently from the point of view of service developers, thus facilitating the realization of widescale entertainment services. REDMAN implements novel lightweight solutions to identify dense MANETs, maintain the desired resource replication degree, and efficiently perform resource retrieval, by exploiting the assumptions of relatively high and almost constant node density to achieve scalability and limited network overhead.     

Scalable monitoring support for resource management and service assurance

Continuous monitoring of network status and its resources are necessary to ensure proper network operation. Deployment of QoS-based value-added services in IP networks necessitates the employment of resource management techniques and specifically the use of traffic engineering. The latter typically relies on monitoring data for both offline proactive and dynamic reactive solutions. The variety of data to be collected and analyzed using different measurement methods and tools, and the extent of monitoring information to use demand a proper QoS monitoring infrastructure. A monitoring system should be scalable in terms of network size, speed, and number of customers subscribed to value-added services. This article investigates the requirements of scalable monitoring system architectures, proposes principles for designing such systems, and validates them through the design and implementation of a scalable monitoring system for QoS delivery in IP differentiated services networks. Experimental assessment results prove the accuracy and scalability of the proposed monitoring system.     

Correlation-based virtual machine migration in dynamic cloud environments

Virtual machine (VM) migration enables flexible and efficient resource management in modern data centers. Although various VM migration algorithms have been proposed to improve the utilization of physical resources in data centers, they generally focus on how to select VMs to be migrated only according to their resource requirements and ignore the relationship between the VMs and servers with respect to their varying resource usage as well as the time at which the VMs should be migrated. This may dramatically degrade the algorithm performance and increase the operating and the capital cost when the resource requirements of the VMs change dynamically over time. In this paper, we propose an integrated VM migration strategy to jointly consider and address these issues. First, we establish a service level agreement-based soft migration mechanism to significantly reduce the number of VM migrations. Then, we develop two algorithms to solve the VM and server selection issues, in which the correlation between the VMs and the servers is used to identify the appropriate VMs to be migrated and the destination servers for them. The experimental results obtained from extensive simulations show the effectiveness of the proposed algorithms compared to traditional schemes in terms of the rate of resource usage, the operating cost and the capital cost.     

Market-based self-optimization for autonomic service overlay networks

Rather than managing their heterogeneity and dynamic behavior through centralized intervention, overlay nodes can be programmed to self-organize and self-manage the network. To achieve the highest performance within a service overlay, they are further expected to self-optimize the network, by cooperatively providing and allocating resources in an optimal manner. However, since nodes are inherently selfish about resources they contribute or consume, self-optimization could not be achieved if they are not given the correct incentives. In this paper, we investigate the effectiveness of a market-based incentive mechanism in directing nodes' behavior and enabling self-optimizations. We have designed an intelligent market model for a service overlay network, based on which individual nodes, being service producers and consumers, determine their own resource contributions, consumptions, or service prices based on their own utility maximization goals. We also propose optimal decision making solutions for nodes to achieve their self-interests; in particular, service providers are provided with a control-based pricing solution based on system identification techniques. With the multicast streaming application as an example, we show through simulations that, even when selfish nodes all seek their maximal utilities, the resulting network still achieves close-to-optimal performance in both steady and dynamic states. The results also indicate that, by encouraging nodes to behave selfishly and intelligently in a designed market, self-optimization in other autonomic systems may be facilitated in the presence of node selfishness.     

Scalable WDM access network architecture based on photonic slotrouting

This paper introduces an approach to solving the fundamental scalability problem of all-optical packet switching wavelength-division multiplexing (WDM) access networks. Current optical networks cannot be scaled by simply adding nodes to existing systems due to the accumulation of insertion losses and/or the limited number of wavelengths. Scalability through bridging requires, on the other hand, the capability to switch packets among adjacent subnetworks on a wavelength basis. Such a solution is, however, not possible due to the unavailability of fast-switching wavelength sensitive devices. In this paper, we propose a scalable WDM access network architecture based on a recently proposed optical switching approach, termed photonic slot routing. According to this approach, entire slots, each carrying multiple packets (one on each wavelength) are “transparently” routed through the network as single units so that wavelength sensitive data flows can be handled using fast-switching wavelength nonsensitive devices based on proven technologies. The paper shows that the photonic slot routing technique can be successfully used to achieve statistical multiplexing of the optical bandwidth in the access network, thus providing a cost-effective solution to today's increasing bandwidth demand for data transmissions     

The autonomic network architecture (ANA)

The objective of autonomic networking is to enable the autonomous formation and parametrization of nodes and networks by letting protocols sense and adapt to the networking environment at run time. Besides its dynamic aspects, a core requirement of autonomic networking is to define a structured framework and execution environment that enables algorithms to operate in a continously changing environment. This paper presents the major design principles of the Autonomic Network Architecture (ANA) and reports on a first implementation. The guiding principle of ANA is to strive for flexibility and genericity at all levels of the architecture. In our approach we explicitly avoid to impose a "one-size-fits-all" architecture (where communication protocols and paradigms are fixed by the architecture). To this end, ANA introduces generic abstractions, for example "information dispatch points" instead of addressable endpoints, as well as communication primitives that support network heterogeneity, adaptability, and evolution. These core abstractions allow for the coexistance of multiple and diverse networking styles and protocols. With the public release of the ANA prototype, we aim at federating autonomics related networking projects, enabling different actors to share, compare, and build upon each other?s work. The ANA runtime can host clean slate network designs as well as legacy Internet technology and serves as a platform for demonstrating autonomic communication principles.     

移动性感知的边缘服务迁移策略

针对移动边缘计算网络中由于用户位置动态变化而导致边缘服务器间负载不均衡、用户服务质量降低的问题,提出了一种移动性感知的边缘服务迁移算法。首先,以最小化用户服务请求感知时延为目标,将优化问题建模为混合整数非线性规划问题。其次,基于Lyapunov优化方法将时延优化问题解耦为边缘服务迁移子问题与无线接入子问题。再次,提出快速边缘决策算法求解出给定无线接入策略情况下最优的资源分配与边缘服务迁移方案。最后,提出异步最佳响应算法迭代出最优无线接入策略。仿真结果表明,与现有服务迁移策略相比较,所提算法能够在保证服务迁移成本稳定的情况下降低用户服务请求的感知时延。     

Connectionless service in an atm-based network

With the advent of connection-oriented broadband in the B-ISDN, the question arises as to how can computers, founding their communication needs on MAC service, profit from the new communication infrastructure? This paper describes the answers by the CCITT to this question and outlines some of the problems to be overcome. Finally, new attempts for the provision of the Connectionless Service are presented.     

在多运营商竞争环境下的接入网建设模式

电信拆分对接入网建设的影响在赞同与反对的讨论声中,原中国电信一分为二。2002年5月16日,中国电信集团公司和中国网络通信集团公司正式成立,由此,我国电信运营市场的5+1格局初步形成。这标志着中国电信市场全局性的战略重组基本完成,对于形成公平有效竞争、加快我国通信事业的发展、推进国民经济和社会信息化,具有重大而深远的意义。重组后的两大集团公司不仅拥有中国电信已有的业务经营范围,还可以在对方区域内建设本地电话网和经营本地固定电话等业务,并相互提供平等接入等互惠服务。电信拆分以后,中国电信集团公司告别了全国性的接入网…     

Topics in network and service management

This is the seventh issue of the series on Network and Service Management that is published twice a year, typically in April and October, although the previous issue had to be published in May (i.e., it was delayed by a month). The series provides articles on the latest developments in this wel established discipline, highlighting recent research achievements and providing insight into both theoretical and practical issues related to the evolution of the discipline from different perspectives. The series provides a forum for the publication of both academic and industrial research, addressing the state of the art, theory, and practice in network and service management.     

Context awareness in network selection for dynamic environments

Mobile devices of new generation are able to connect to multiple networks and to constitute new infrastructureless networks. These dynamic environments require new security paradigms and automatic mechanisms to minimize user intervention. Our goal is the definition of a new concept of distance that considers the current domain constraints and the user preferences. This paper addresses some of the problems of these complex environments by using Multidimensional Scaling (MDS) techniques. We also propose collaborative mechanisms for automatic environment marking. Based on these ideas we have developed Pervasive Interaction Manager (PervsIM), a decision mechanism that selects the most appropriate network or peer to interact with. Besides we have defined an embedded access control module which ensures that PervsIM decisions are followed by all applications. Furthermore, several simulation results and implementation details outline how these results can be incorporated in today’s mobile devices.     

MPEG-2 SNR可分度编码器及其在ATM网络上的应用

在数字图像压缩数据传输的领域，ＭＰＥＧ－２标准的可分度编码算法可以应用于ＡＴＭ网络上的优先级控制方案中，以对网络拥塞进行有效的控制。下文论述了ＭＰＥＧ－２ ＳＮＲ可分度编码器的实现方法和它应用于ＡＴＭ网络分层传输时的优越性。给出的一些实验数据初步说明了它能够在网络发生拥塞时保证基本图像质量。