主动网络体系结构分析和设计

由于当前Ｉｎｔｅｒｎｅｔ是不可编程的,难以提供各种新的网络服务,并且新协议配置困难。业界对可编程网络体系结构进行了广泛深入的研究,提出了主动网络模型来解决当前基于ＩＰ模型的各种问题。文中先回顾了主动网络的发展历史,综述当前的发展动态,然后比较了两种目前成功的两种主动网络体系结构,并分析了它们的性能。最后,我们综合了两种体系结构的优点,提出了自己的主动网络体系结构以及下一步的研究重点。     

A secure active network environment architecture: realization inSwitchWare

An active network is a network infrastructure which is programmable on a per-user or even per-packet basis. Increasing the flexibility of such network infrastructures invites new security risks. Coping with these security risks represents the most fundamental contribution of active network research. The security concerns can be divided into those which affect the network as a whole and those which affect individual elements. It is clear that the element problems must be solved first, since the integrity of network-level solutions will be based on trust in the network elements. In this article we describe the architecture and implementation of a secure active network environment (SANE), which we believe provides a basis for implementing secure network-level solutions. We guarantee that a node begins operation in a trusted state with the AEGIS secure bootstrap architecture. We guarantee that the system remains in a trusted state by applying dynamic integrity checks in the network element's runtime system, using a novel naming system, and applying node-to-node authentication when needed. The construction of an extended LAN is discussed     

Application level active network (alan) server management architecture

This paper presents the details of the policy-based security and resource management architecture for Application Level Active Network (alan) servers.alan is an active network architecture which enables deployment of user-customised processes (proxylets), which enhance the existing services or introduce new services to the end-user, on the select group of servers in anip network. The issues of security and resource management in this scenario are of crucial importance so as to efficiently facilitate and control the resource consumption of user-specified processes on the active servers, as well as to protect the server platforms from unauthorised proxylet deployment or malevolent behaviour. The architecture allowing efficient resource and security control is presented in this paper, including detaileduml diagrams capturing the management functionality, as well as a set of concrete management policies for thealan scenario. The examplexml policies are also given, and the deployment of this architecture in real-life trials is described. This development forms a part of a larger management architecture foralan-enabled networks developed in the context of theist projectandroid (Active Network DistRibuted Open Infrastructure Development).     

The double-layer network architecture for photonic switching

This paper introduces a new architecture for strictly nonblocking multistage photonic space networks implemented using the switched directional couplers. This switching architecture has the lowest path loss and the best SNR performance of any nondilated network. The architecture can also be dilated, giving it even better SNR     

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.     

The NetScript active network system

NetScript is a language system for dynamically programming and deploying protocol software in an active network. NetScript programs are packet flow processors composed out of dataflow components. They can be dynamically dispatched to remote nodes, composed with installed software, and executed to enhance node functions. NetScript has proven useful for implementing a variety of practical network systems including Internet protocol (IP) routers, firewalls, protocol analyzers, traffic shapers, load balancers, various queuing disciplines, intrusion detection systems, Web transport protocols, and IP telephony systems. The paper illustrates the principal concepts of NetScript with an example application, an active IP router that is dynamically extended to provide firewall protection     

The JOURNEY active network model

Faster processors are quickly enabling a new class of computationally intensive applications that actively transform information flows. Performing such computation at the terminal end is contrary to current trends toward low-power terminal devices. Moreover, scalability and efficiency concerns are also encouraging service providers to outsource computation when operating under loaded conditions. To address the problem of deploying such applications, we introduce the JOURNEY network model, which provides computation as an integrated network service. Contrary to other distributed computing models, JOURNEY does not attempt to guarantee that a given computational job will indeed be completed. Instead, the JOURNEY model trades off such hard guarantees in favor of architectural simplicity, and hence scalability. In order for the JOURNEY model to be applicable to real-time multimedia flows, we introduce the notion of soft quality-of-service (QoS) that provides a probabilistic bound on the unprocessed packet rate (UPR). Based on this notion, we describe a packet-processing admission control algorithm that additionally takes into consideration a flow's real-time constraints. We also propose a computing router architecture that is based on cluster technology. This architecture can track technology advances in both routing and computing independently. We further present a motivating multimedia application that employs a semantically driven video transcoding service within the JOURNEY framework we implemented, and describe our experience along with performance measurements     

Multiple-availability-level ATM network architecture

Because of their high flexibility, ATM networks have the potential to achieve two objectives: switch cost reduction and multi-level network availability. For that purpose, this article proposes to use virtual circuit (VC) route self-healing schemes to achieve a multiple-availability-level ATM network. Flexible multi-QoS logical ATM network (Full-Net), a new concept for ATM networks, is now being studied at NTT Laboratories. Full-Net is a very flexible network design strategy for survivable networks that is based on a self-healing VC network. Defining several logical configurations of the VC network allows us to support multiple levels of network availability, simplifies the adaptation to future and unknown service requirements, and significantly reduces overall ATM network cost. Offering different levels of availability not only saves the network's resources, but also allows the network operator to provide its customers with services at the most appropriate cost. We introduce the advantages of VC route restoration for ATM networks, and compare virtual path (VP) level and physical level restoration strategies. We explain Full-Net's concept, propose a VC route self-healing scheme, and show the impact of the logical network configurations on network survivability and resource management     

An all-optical network architecture

A novel photonic network, MATRIX (for multi-wavelength all-optical transparent information exchange), is proposed in this paper. The all-optical multihop network supports wavelength continuity and provides a very high network capacity. Spatial reuse of wavelengths as well as the multiplicity of fibers in optical fiber cables are exploited and enable the interconnection of N² network nodes with merely N wavelengths. The node structure is simple since neither tunable devices nor wavelength converters are required. Packets are routed through the network by photonic fast packet switching as well as by wavelength and experience a maximum hop number of two. Multiple optical paths between any pair of nodes provide a good network survivability     

RACE telecommunications management network architecture

An implementation architecture for a telecommunications management network (TMN) suitable for the management of integrated broadband communications in the CEC RACE programme is described. The architecture is intended to support the future implementation of TMN systems within Europe and elsewhere. Having outlined some of the motivations for the development of a TMN architecture, the paper introduces the various functions associated with a TMN. An overview is given of the functional and physical views of the TMN. One of the major components of any network management system is the management information base. This is described in some detail because of its central role in the architecture. Finally a list of some of the open issues still remaining concludes the paper     

MIRAI architecture for heterogeneous network

One of the keywords that describe next-generation wireless communications is "seamless." As part of the e-Japan Plan promoted by the Japanese Government, the Multimedia Integrated Network by Radio Access Innovation project has as its goal the development of new technologies to enable seamless integration of various wireless access systems for practical use by 2005. This article describes a heterogeneous network architecture including a common tool, a common platform, and a common access. In particular, software-defined radio technologies are used to develop a multiservice user terminal to access different wireless networks. The common platform for various wireless networks is based on a wireless-supporting IPv6 network. A basic access network, separated from other wireless access networks, is used as a means for wireless system discovery, signaling, and paging. A proof-of-concept experimental demonstration system is available     

FTTH网络结构分析

文章描述了光纤到户（FTTH）在通信网中的位置及作用,FTTH系统的网络结构及功能要求。在FTTH的网络结构方面,通过对各种方案进行比较,建议在不同的应用环境中采取不同的网络方案。这些方案包括光纤到大楼（FTTB）的光网络,基于点到点的纤分方式,基于点到点结构的有源光网络,基于IEEE的以太网无源光网络（EPON）系统和基于ITU—T的吉比特无源光网络（GPON）的系统。     

The dilated slipped Banyan switching network architecture for usein an all-optical local-area network

A modification of the classical banyan switching network architecture, called the dilated slipped banyan, is described. This architecture is recursive and switching networks of any size perform permutation switching under a simple switching rule. They also exhibit column-control and dilation, properties that are particularly relevant to guided-wave and free-space photonic technologies. A photonic switching network, with this dilated slipped banyan architecture, is proposed as the hub of an all-optical active-star local-area network. The switching assignment at this hub is time-multiplexed on a fixed schedule that is known to all the terminals. This all-optical local-area network provides the equivalent of full-connectivity with high simultaneous data rates between every pair of terminals. A 16-terminal local-area network with 100 Mb/s of contention-free bandwidth between every pair of terminals is described     

网络病毒主动预警模型

对比于传统的主机病毒，在开放式网络环境中，网络病毒疫情的蔓延更加迅速、破坏力也更强，建立行之有效的预警体系，是尽早发现新型网络病毒，并控制其蔓延的有力举措。本文研究主动式病毒疫情预警体系结构模型，实时分析网络上的疫情信息；通过基于流量的检测，实现对于新型未知网络病毒的挖掘。     

传送网体制的革命--智能交换光网络

基于IP over WDM技术的光互联网被公认是目前实现数据网和光网融合的最有前途的网络解决方案。围绕这种方案出现了多种IP层和光层的新适配技术和新思路，如多协议标签交换(MPLS)及其扩展的通用多协议标签交换(GMPLS)、多协议波长标签交换、SDH、10G以太网、简单数据链路（SDL）和数字包封(DW)等，但由于IP业务量本身的不确定性和不可预见性，对网络带宽的动态分配要求显得尤为迫切，传统的人工或半永久性的网络连接配置方式难以满足业务拓展和市场竞争的需要。一种能够自动完成网络连接的新型网络—自动交换传送网(ASTN)应运而…     

ATMTN: a telemammography network architecture

One of the goals of the National Cancer Institute (NCI) to reach more than 80% of eligible women in mammography screening by the year 2000 yet remains as a challenge. In fact, a recent medical report reveals that while other types of cancer are experiencing negative growth, breast cancer has been the only one with a positive growth rate over the last few years. This is primarily due to the fact that 1) examination process is a complex and lengthy one and 2) it is not available to the majority of women who live in remote sites. Currently for mammography screening, women have to go to doctors or cancer centers/hospitals annually while high-risk patients may have to visit more often. One way to resolve these problems is by the use of advanced networking technologies and signal processing algorithms. On one hand, software modules can help detect, with high precision, true negatives (TN), while marking true positives (TP) for further investigation. Unavoidably, in this process some false negatives (FN) will be generated that are potentially life threatening; however, inclusion of the detection software improves the TP detection and, hence, reduces FNs drastically. Since TNs are the majority of examinations on a randomly selected population, this first step reduces the load on radiologists by a tremendous amount. On the other hand, high-speed networking equipment can accelerate the required clinic-lab connection and make detection, segmentation, and image enhancement algorithms readily available to the radiologists. This will bring the breast cancer care, caregiver, and the facilities to the patients and expand diagnostics and treatment to the remote sites. This research describes asynchronous transfer mode telemammography network (ATMTN) architecture for real-time, online screening, detection and diagnosis of breast cancer. ATMTN is a unique high-speed network integrated with automatic robust computer-assisted diagnosis-detection/digital signal processing (CAD/DSP) methods for mass detection, region of interest (ROI) compression algorithms using Digital Imaging and Communications in Medicine (DICOM) 3.0 medical image standard. While ATMTN has the advantage of higher penetration for cancer screening, it provides the diagnosis with higher efficiency, better accuracy and potentially lower cost. This paper presents the development of the infrastructure and algorithm design for ATMTN-based telemammography. The research goals involved: 1) networking stations for telemammography to demonstrate, evaluate, and validate technologies and methods for delivering mammography screening services via high-speed (155 MB/s) links, performing real-time network-transmitted, high-resolution mammograms for immediate diagnosis as a "second opinion" strategy; 2) development of object-oriented compression methods for storage, retrieval and transmission of mammograms; 3) inclusion and optimization of detection algorithms for identification of normal images in different resolutions to increase the speed and effectiveness of telemammography as a "second opinion" strategy; 4) resolving the compatibility issues between images from different equipment (DICOM standards); and 5) optimization of an integrated ATMTN with adaptive CAD/DSP methods that are robust for large image databases and input sources.     

Wireless in-building network architecture and protocols

The topology, protocols and architecture for an 18-GHz wireless in-building network (WIN) aimed at office environments are described. The problems of controlling an array of directional antennas, using half-duplex radios and compensating for channel errors are addressed. The protocols provide robustness in the face of changing radio environment that requires no user intervention and provides low user delay and high system throughput     

A federated peer-to-peer network game architecture

A federated peer-to-peer game is one in which many small areas of interest within a game each supported using a peer-to-peer model are "knitted" together to form a game capable of supporting a very large number of players. Our work has involved determining whether such an architecture is a feasible alternative to the more common central server architecture for supporting large multiplayer network games.     

An hierarchical VLSI neural network architecture

As neural network systems are scaled up in size it will become extremely difficult, if not impossible, to maintain full connectivity. A digital architecture which exhibits hierarchical connectivity similar to that observed in many biological neural networks is described. At the lowest level, clusters of fully connected neurons correspond to subnetworks. These subnetworks are then sparsely connected to form the complete neural network system. The architecture exploits the inherent density and large bandwidth of on-chip RAM and can use either a large number of bit-serial processors or a reduced number of bit-parallel processors. A prototype chip which implements a complete subnetwork has been fabricated in 3-μm CMOS and is fully functional