HFC网络设备管理系统在保定市广电网络的应用

本文重点介绍了保定市区HFC网络设备管理系统组成、总体架构以及主要功能。     

Diagnosing Traffic Anomalies Using a Two-Phase Model

Network traffic anomalies are unusual changes in a network,so diagnosing anomalies is important for network management.Feature-based anomaly detection models (ab)normal network traffic behavior by analyzing packet header features.PCA-subspace method (Principal Component Analysis) has been verified as an efficient feature-based way in network-wide anomaly detection.Despite the powerful ability of PCA-subspace method for network-wide traffic detection,it cannot be effectively used for detection on a single link.In this paper,different from most works focusing on detection on flow-level traffic,based on observations of six traffic features for packet-level traffic,we propose a new approach B6SVM to detect anomalies for packet-level traffic on a single link.The basic idea of B6-SVM is to diagnose anomalies in a multi-dimensional view of traffic features using Support Vector Machine (SVM).Through two-phase classification,B6-SVM can detect anomalies with high detection rate and low false alarm rate.The test results demonstrate the effectiveness and potential of our technique in diagnosing anomalies.Further,compared to previous feature-based anomaly detection approaches,B6-SVM provides a framework to automatically identify possible anomalous types.The framework of B6-SVM is generic and therefore,we expect the derived insights will be helpful for similar future research efforts.     

1550nm HFC城域网双向传输方式和新技术的探讨

近年来，随着有线电视数字化的不断推进，有线电视网络正由单一的模拟广播业务平台向综合业务平台的方向发展。国家-省-地市-县之间的广电网络也逐步通过光纤上下贯通，一个世界上最大的有线电视网络正在我国编织起来。     

浅析中等城市双向HFC光纤环网的构建及设备配置

随着中国的有线电视向数字化、多功能化、产业化和全国联网的方向发展．各地有线电视网都在积极地进行网络的改造升级。以光纤为骨干．光节点到小区，同轴电缆接入用户的HFC网络正成为全国有线电视城域网改造升级的首选目标。公众对信息需求量的不断增加，促使有线电视网由单一广播式传送到双向交互式的多媒体宽带网络方向发展。有线电视传输网将建成一个大容量、宽频带、标准化、数字化的双向传输广播电视节目和综合数据信息的传输系统。     

基于流量信息结构的异常检测

由于人们对网络流量规律的认识还不够深入,大型高速网络流量的异常检测仍然是目前测量领域研究的一个难点问题.通过对网络流量结构和流量信息结构的研究发现,在一定范围内,正常网络流量的IP、端口等具有重尾分布和自相似特性等较为稳定的流量结构,这种结构对应的信息熵值较为稳定.异常流量和抽样流量的信息熵值以正常流量信息熵值为中心波动,构成以IP、端口和活跃IP数量为维度的空间信息结构.据此对流量进行建模,提出了基于流量信息结构的支持向量机(support vector machine,简称SVM)的二值分类算法,其核心是将流量异常检测转化为基于SVM的分类决策问题.实验结果表明,该算法具有很高的检测效率,还初步验证了该算法的抽样检测能力.因此,将该算法应用到大型高速骨干网络具有实际意义.