IP router architectures: an overview

In the emerging environment of high performance IP networks, it is expected that local and campus area backbones, enterprise networks, and internet service providers (ISPs) will use multigigabit and terabit networking technologies where IP routers will be used not only to interconnect backbone segments but also to act as points of attachments to high performance wide area links. Special attention must be given to new powerful architectures for routers in order to play that demanding role. In this paper, we identify important trends in router design and outline some design issues facing the next generation of routers. It is also observed that the achievement of high throughput IP routers is possible if the critical tasks are identified and special purpose modules are properly tailored to perform them. Copyright © 2001 John Wiley & Sons, Ltd.     

Advances in photonic packet switching: an overview

The current fast-growing Internet traffic is demanding more and more network capacity every day. The concept of wavelength-division multiplexing has provided us an opportunity to multiply network capacity. Current optical switching technologies allow us to rapidly deliver the enormous bandwidth of WDM networks. Photonic packet switching offers high-speed, data rate/format transparency, and configurability, which are some of the important characteristics needed in future networks supporting different forms of data. In this article we present some of the critical issues involved in designing and implementing all-optical packet-switched networks     

An overview of routing optimization for internet traffic engineering

Traffic engineering is an important mechanism for Internet network providers seeking to optimize network performance and traffic delivery. Routing optimization plays a key role in traffic engineering, finding efficient routes so as to achieve the desired network performance. In this survey we review Internet traffic engineering from the perspective of routing optimization. A taxonomy of routing algorithms in the literature is provided, dating from the advent of the TE concept in the late 1990s. We classify the algorithms into multiple dimensions: unicast/multicast, intra-/inter- domain, IP-/MPLS-based and offline/online TE schemes. In addition, we investigate some important traffic engineering issues, including robustness, TE interactions, and interoperability with overlay selfish routing. In addition to a review of existing solutions, we also point out some challenges in TE operation and important issues that are worthy of investigation in future research activities.     

面向多网络体制并存的开放式可重构路由器体系结构设计与实践

针对现有网络设备在支持可重构和多网络体制并存方面存在的不足,提出了一种面向多网络体制并存的开放式可重构路由器体系结构。通过在控制、转发和交换体系结构设计上,采用虚拟化和硬件分区配置技术,能够对控制、转发和交换进行资源划分与隔离,将路由器中同一个硬件资源虚拟化为多个功能上独立、资源上隔绝的逻辑路由器实例,提高了核心路由器设备的开放性和安全性。     

线速路由器分组并行处理体系结构与性能分析

本文在分析路由器报文献处理需求的基础上,探讨了报文多处理模块并处理的体系结构,并以四个处理模块为例对分组处理时延做了定量分析和仿真。分析表明,当各模块处理能力总和与单独模块结构处理能力相同时,多模块结构处理时延将大于单模块结构;当各模块处理能力总和大于单处理模块结构处理能力的同时,系统处理的时延特性可得到明显改善,并且系统具有较好的可扩充性。     

Performance analysis of a traffic engineering solution for multilayer networks based on the GMPLS paradigm

This paper presents an integrated traffic engineering (TE) system for new generation multilayer networks based on the generalized multiprotocol label switching (GMPLS) paradigm, and reports the performance analysis of such a system. The proposed TE system aims at dynamically reacting to traffic changes and, at the same time, fulfilling quality of service (QoS) requirements for different classes of service. The proposed solution consists of a hybrid routing approach and a bandwidth management strategy. The former makes use of both off-line and on-line methods to accommodate traffic requests. The latter, based on an "elastic" use of the bandwidth, allows the handling of different priorities among data flows, possible preemptions, and rerouting. The proposed TE permits the accommodation of the largest amount of traffic, while guaranteeing good performance to mission-critical services. The main building blocks and the operations of the system are reported and the major advantages are discussed. The performance of the proposed system are compared with the ones relating to a reasonable alternative system based on overprovisioning, to highlight its advantages of in terms of traffic volume that can be accommodated for a given network infrastructure.     

The generic framing procedure (GFP): an overview

The generic framing procedure (GFP) is a standardized traffic adaptation protocol for broadband transport applications. It provides an efficiency and QoS-friendly mechanism to map either a physical layer or logical link layer signal to a byte-synchronous channel. It also supports basic client control functions for client management purposes. This article presents a brief overview of GFP     

Wafer level chip scale packaging (WL-CSP): an overview

Several wafer level chip scale package (WLCSP) technologies have been developed which generate fully packaged and tested chips on the wafer prior to dicing. Many of these technologies are based on simple peripheral pad redistribution technology followed by attachment of 0.3-0.5 mm solder balls. The larger standoff generated by these solder balls result in better reliability for the WLCSP's when underfill is not used than for equivalent flip chip parts. Rambus^TM RDRAM and integrated passives are two applications that should see wide acceptance of WLCSP packages     

On intranode impairments and engineering rules for an optical label switching router supporting an FSK/IM labeling scheme

This paper presents a study on intranode impairments and engineering rules for a label switching router supporting intensity modulated (IM) optical payload data signals labeled by using frequency-shift key (FSK) modulation. Engineering rules and design guidelines are presented regarding the choice of system parameters such as IM extinction ratio, FSK frequency deviation, alignment of optical filtering stages, label swapping, and node cascadability. The presented rules are derived from insights obtained from computer simulations and experimental validation for a 10-Gb/s IM payload signal.     

Power-domain non orthogonal multiple access (PD-NOMA) in cooperative networks: an overview

Wireless Networks - Non-orthogonal multiple access (NOMA) scheme is emerging as a favourable multiple access scheme for future 5G networks. Compared to orthogonal multiple access techniques, NOMA...     

TOR（洋葱路由）应用面临的挑战与对策建议

匿名通信系统洋葱路由器(TOR)在网络通信中可以有效地防止流量分析和监听,很好地保护用户隐私,但是也正因为其"匿名通信"的特性,面临着被犯罪分子滥用、情报机构监控等的风险与挑战。技术本身是中立的,如何使技术为人类发展所用是人们进行技术研发的最终目的。在介绍TOR基本原理、应用现状的基础上,重点对TOR应用中面临的风险和挑战进行了分析,并从技术设计、技术滥用的控制以及网络信息保护等方面提出了相应的对策建议。     

会议电视会场系统工程设计概述

结合《会议电视会场系统工程设计规范》GB50635-2010的要求,介绍了会议电视会场系统中音频系统、视频系统、灯光系统和会场环境设计的主要内容,并通过工程实例进一步阐述会场系统的设计方案.     

Terahipas: a modular and expandable terabit/second hierarchicallymultiplexing photonic ATM switch architecture

A terabit/second hierarchically multiplexing photonic asynchronous transfer mode (ATM) switch network architecture, called Terahipas, is proposed. It combines the advantages of photonics (a large bandwidth for transport of cells) and electronics (advanced logical functions for controlling, processing, and routing). It uses a hierarchical photonic multiplexing structure in which several tens of channels with a relatively low bit rate, say 2.4 Gb/s, are first time-multiplexed on an optical highway by shrinking the interval between optical pulses, then a number of optical highways are wavelength-multiplexed (or space-division multiplexed). As a result, the switch capacity can be expanded from the order of 100 Gb/s to the order of 10 Tb/s in a modular fashion. A new implementation scheme for cell buffering is used for eliminating the bottleneck when receiving and storing concurrent optical cells at bit rates as high as 100 Gb/s. This new architecture can serve as the basis of a modular, expandable, high-performance ATM switching system for future broad band integrated service digital networks (B-ISDN's)     

高效可扩展的应用层流量识别架构

提出一种采用自定义识别方法描述语言和识别操作树的高效可扩展的应用层流量识别架构(ARTIST).在流量识别方法的描述模型分析的基础上,设计了识别方法和识别规则描述语言以及对应的识别引擎,实现各种主要流量识别方法,并可动态扩展新的识别方法.采用识别规则树结构维护识别规则,缩短了协议识别流程,提高了识别性能.实验证明ARTIST不仅能够支持对各类的流量识别方法和规则的动态更新,而且能够提高系统识别性能.     

Wireless communications and networking: an overview

This paper presents an overview of wireless local-area networks (LANs) and wireless personal area networks (PANS), with emphasis on the two most popular standards: IEEE 802.11, and Bluetooth. While there are many such surveys in the current literature and online, we attempt here to present wireless LANs and PANS in a unified fashion as a viable alternative to wired LANs, while stressing the remaining challenges and limitations     

Absolute band gap engineering of anisotropic square and triangular photonic crystals

We analyze the band gap properties of two-dimensional photonic crystals created by square and triangular lattices of rods, considering that the rods are formed of a dielectric core surrounded by an interfacial layer of anisotropic tellurium. Using the plane wave analysis, we study the modification of the band gap spectrum when the rods are infiltrated with different dielectric core and discuss the optimization strategies leading to the maximum value of the absolute band gap.     

Video transcoding architectures and techniques: an overview

Throughout this article, we concentrate on the transcoding of block-based video coding schemes that use hybrid discrete cosine transform (DCT) and motion compensation (MC). In such schemes, the frames of the video sequence are divided into macroblocks (MBs), where each MB typically consists of a luminance block (e.g., of size 16 /spl times/ 16, or alternatively, four 8 /spl times/ 8 blocks) along with corresponding chrominance blocks (e.g., 8 /spl times/ 8 Cb and 8 /spl times/ 8 Cr). This article emphasizes the processing that is done on the luminance components of the video. In general, the chrominance components can be handled similarly and will not be discussed in this article. We first provide an overview of the techniques used for bit-rate reduction and the corresponding architectures that have been proposed. Then, we describe the advances regarding spatial and temporal resolution reduction techniques and architectures. Additionally, an overview of error resilient transcoding is also provided, as well as a discussion of scalable coding techniques and how they relate to video transcoding. Finally, the article ends with concluding remarks, including pointers to other works on video transcoding that have not been covered in this article, as well as some future directions.     

Testing communication and computer networks: an overview

Many activities in today's organizations are becoming ever more dependent on communications and computer networks, and network managers are faced with the enormous challenge of increasing the availability and efficiency of their infrastructures, which grow both in size and complexity. This makes it crucial to plan network operation systematically, to define and implement appropriate procedures for regular monitoring and performance assessment, and to set up proper tools for maintenance and troubleshooting purposes. Furthermore, proactive network testing must be pursued; it is vital to gather some ideas of normal network operation documented in order to have a comparison term when problems occur. The article has dealt with the measurement instruments and procedures currently adopted for network testing and advances in the field for the I&M research community.