广播电视信息网络公司的建设与运营

广电网络公司对传输有线电视节目、开展多功能业务具有重要的作用，建设与运营好广电网络公司对开展宣传和广电信息化建设具有重要的意义，通过对网络公司业务的分析，提出广电网络公司建设与运营的设想。     

无线移动网络的综合服务模型与资源预留研究

本文讨论了无线移动网络的综合服务模型,提出应按照服务承诺是否移动相关以及资源是否独占来对实时服务进行分类,并定义了组成该综合服务模型的五种服务承诺.本文同时还讨论了移动无关与移动相关服务的资源预留解决方案,提出在移动无关服务中用移动代理技术建立端-端的主动预留与被动预留,而在移动相关服务中只建立主动的端-端预留并在相关的无线链路上被动预留资源.     

一种构建CORBA Trader服务集群的方法

OMG的Trader服务是分布对象的“中介”服务，在大规模分布环境下，对Trader服务的需求日益显得迫切．单一节点的Trader服务其本身会变成分布应用的性能瓶颈．本文提出了一种基于一致性Hash方法的Cache节点定位算法和Trader Cache集群框架，并对该框架的负载均衡能力和请求响应能力进行了测试。     

Workloads and waiting times in single-server systems with multiple customer classes

One of the most fundamental properties that single-server multi-class service systems may possess is the property of work conservation. Under certain restrictions, the work conservation property gives rise to a conservation law for mean waiting times, i.e., a linear relation between the mean waiting times of the various classes of customers. This paper is devoted to single-server multi-class service systems in which work conservation is violated in the sense that the server's activities may be interrupted although work is still present. For a large class of such systems with interruptions, a decomposition of the amount of work into two independent components is obtained; one of these components is the amount of work in the corresponding systemwithout interruptions. The work decomposition gives rise to a (pseudo)conservation law for mean waiting times, just as work conservation did for the system without interruptions.     

线程池技术的研究

服务器程序利用线程技术响应客户请求已经司空见惯 ,但不同的实现方式可能会对服务器的效率产生很大影响。使用线程池技术可以显著地改善服务器应用程序的性能。文章介绍了线程池技术的设计模型、基本原理及优化方法 ,并讨论了服务器程序如何利用线程池来优化性能     

基于流量工程的新型Internet网络规划研究

本文根据Internet的新兴发展和对服务质量的要求，提出一种新型网络规划的模型，根据模型的特点分析了新型网络规划需要处理的约束和需要使用的路由策略，并应用进化算法一遗传算法对此模型进行求解。求解时，对需要解决的几个关键问题都给出了相应的解决方法。最后的软件仿真结果证实了方法的可行性和优越性。新型网络规划的研究对现在和未来的网络优化和网络规划的研究有重要的启发和应用价值。     

A hop‐by‐hop delay‐constrained routing algorithm with explicit loop avoidance and backup routing information

QoS Routing is crucial for QoS provisioning in high‐speed networks. In general, QoS routing can be classified into two paradigms: source routing and hop‐by‐hop routing. In source routing, the entire path to the destination node of a communication request is locally computed at the source node based on the global state that it maintains, which does not scale well to large networks. In hop‐by‐hop routing, a path‐selecting process is shared among intermediate nodes between the source node and the destination node, which can largely improve the protocol scalability. In this paper, we present the design of hop‐by‐hop routing with backup route information such that each intermediate node can recursively update the best known feasible path, if possible, by collectively utilizing the routing information gathered thus far and the information that it locally stores. Such a route is kept as a backup route and its path cost is used as a reference to guide the subsequent routing process to search for a lower‐cost constrained path and avoid performance degradation. In this way, the information gathered is maximally utilized for improved performance. We prove the correctness of our presented algorithm and deduce its worst message complexity to be O(∣V∣²), where ∣V∣ is the number of network nodes. Simulation results indicate that, however, the designed algorithm requires much fewer messages on average. Therefore it scales well with respect to the network size. Moreover, simulation results demonstrate that the cost performance of our algorithm is near‐optimal. Copyright © 2004 John Wiley & Sons, Ltd.     

走向网络的多媒体视频服务展望

本文着眼于未来，论述了多媒体技术的发展，在视频服务方面的应用，以及它的发展和对未来的广播电视事业产生的影响。     

Analysis of a discrete-time queueing system with time-limited service

We analyze a discrete-time, single-server queueing system in which the length of each service period is limited. The server takes a vacation when the limit expires or the queue empties, whichever occurs first. In the former case, the preempted service is resumed after the vacation without loss or creation of any work. This system models the transmission of message frames from a station on timed-token local-area networks (for example, FDDI and IEEE 802.4 token bus). We study the process of the unfinished work and the joint process of the queue size and the remaining service time. By using the technique of discrete Fourier transforms to determine some unknown functions in the governing equations, we numerically obtain exact mean waiting times.A part of the work of H. Takagi was done while he was with IBM Research, Tokyo Research Laboratory.     

FMD: A DoS mitigation scheme based on flow migration in software‐defined networking

Software‐defined networking (SDN) emerges as the next generation of networking architecture, aiming to improve the network manageability and adaptability. However, because of the centralized control policy, SDN is liable to suffering from the denial of service attack in both the data plane and the control plane. To resist the attack and prevent the network from being paralyzed, we propose a novel mitigation scheme named flow migration defense, which uses a slave controller as a substitution to endure flooding requests mitigated from the master controller. Considering the special case that the normal requests may be regarded as the malicious ones, these requests are reforwarded back to the master controller on the basis of the round‐robin scheduling. To prevent the master controller from being flooded by the reforwarded requests, we design the adaptive rate adjustment method to adjust the reforwarding rate. Compared with multilevel feedback queue and FloodDefender, simulations demonstrate that flow migration defense can mitigate the SDN‐aimed denial of service attack efficiently with a better performance in terms of request response time, packet loss rate, and mitigation time.