基于LDP的MPLS网络流量统计功能的研究

随着MPLS(Multi-Protocol Label Switch)技术的逐步成熟,其承载的业务越来越丰富,网络流量成为描述网络行为的重要指标之一.主要介绍了分布式设备中基于LDP(Label Distribute Protocol)的MPLS网络流量统计功能的实现,详细阐述了系统模块的交互关系、处理流程以及主要的函数接口与数据结构,最后对该功能进行组网测试.测试结果证明了LSP(Label Switch Path)流量统计功能的有效性,能很好地满足用户、运营商的业务需求.     

Recovery from control plane failures in the LDP signalling protocol

The Label Distribution Protocol (LDP) needs to recover its state information after a control plane failure, so that the established connections in the data plane are not disrupted by any new connection set-up. We propose a backup mechanism to store the LDP state information in an upstream neighbour node. The backup LDP state information is synchronized with the original LDP state information in a downstream node when the LDP sets up or tears down connections. Then, we propose a two-step LDP state information recovery, which uses a fast LDP state information recovery to recover what labels are idle before a control plane failure, and a detailed LDP state information recovery to fully recover all LDP state information. The fast LDP state information recovery is realized as part of the LDP initialization, allowing a restarting LDP session to process new connection set-up requests as soon as possible, without interfering existing connections. The detailed LDP state information recovery performs in the background in parallel to the normal LDP operations. When an LDP connection teardown requires the LDP state information that has not yet been recovered, an on-demand query based LDP state information recovery is conducted. The performance analysis demonstrates that our proposal achieves fast LDP recovery for the core label state information. It features scalable LDP state information storage and recovery by only involving a pair of neighbour nodes.     

ATM和MPLS网络互通技术的研究

ATM（Asynchronous Transfer Mode）网络与MPLS（Multi Protocol Label Suitching）网络之间的互通是一个尚待解决的问题，目前国际上对ATM和MPLS网络之间的互通还没有形成最终方案。研究了ATM和MPLS之间的互通，根据ATM论坛提出的互通模型探讨了两个ATM网络经过一个MPLS网络时遇到的问题。研究结果表明，ATM—MPLS网络的互通可以支持原有的业务，并实现原有网络的平滑过渡与升级。     

对芳香聚酰胺海水反渗透复合膜元件高压测试系统的修正

以简便实用的公式，介绍了芳香聚酰胺海水反渗透复合膜元件在非标准条件下的膜指标Fa(T,Cf,p,Y)与标准测试条件下的膜指标Fs(25℃，32000mg/L,5500kPa,8%）的相互关系。     

凹印蚀刻制作RFID标签天线应注意的问题

RFID标签（无线射频系统）已在许多领域推广应用。在RFID标签制作中，蚀刻法是常见的一种制作方法。文章主要介绍凹印蚀刻制作RFID标签天线的技术要领。     

MPLS组播流量工程综述

介绍了MPLS网络、组播技术和流量工程技术的特点与特征,结合它们之间的优势和对单播与组播流量工程的比较,重点综述了目前在MPLS网络上实施组播流量工程的几种建树方法、发展现状和存在的问题,最后对MPLS组播流量工程的研究作出了展望.     

Label propagation via bootstrapped support vectors for semantic relation extraction between named entities

This paper proposes a semi-supervised learning method for semantic relation extraction between named entities. Given a small amount of labeled data, it benefits much from a large amount of unlabeled data by first bootstrapping a moderate number of weighted support vectors from all the available data through a co-training procedure on top of support vector machines (SVM) with feature projection and then applying a label propagation (LP) algorithm via the bootstrapped support vectors and the remaining hard unlabeled instances after SVM bootstrapping to classify unseen instances. Evaluation on the ACE RDC corpora shows that our method can integrate the advantages of both SVM bootstrapping and label propagation. It shows that our LP algorithm via the bootstrapped support vectors and hard unlabeled instances significantly outperforms the normal LP algorithm via all the available data without SVM bootstrapping. Moreover, our LP algorithm can significantly reduce the computational burden, especially when a large amount of labeled and unlabeled data is taken into consideration.     

Fast connected-component labeling

Labeling of connected components in a binary image is one of the most fundamental operations in pattern recognition: labeling is required whenever a computer needs to recognize objects (connected components) in a binary image. This paper presents a fast two-scan algorithm for labeling of connected components in binary images. We propose an efficient procedure for assigning provisional labels to object pixels and checking label equivalence. Our algorithm is very simple in principle, easy to implement, and suitable for hardware and parallel implementation. We show the correctness of our algorithm, analyze its complexity, and compare it with other labeling algorithms. Experimental results demonstrated that our algorithm is superior to conventional labeling algorithms.     

基于MPLS流量工程的路径最优排序算法

针对多协议标记交换（MPLS）网络流量工程的路由选择问题,在分析已有算法的基础上,提出一种路径最优排序算法。该算法使用一种学习机,根据随机网络环境提供的信息自动学习,计算出最佳路由优先顺序,按此顺序确定最佳转发路径。仿真结果表明该算法路由拒绝率低、计算速度快,并且能够有效地保证网络服务质量,是一种高效快捷的路由选择算法。     

基于IPv6流标签的服务质量研究

IPv6作为新一代的互联网协议,对IP网络的服务质量提供了很好的支持,尤其是其报头中20位的流标签的使用,更是比IPv4的尽力而为服务有了很大的提高。本文介绍了IPv6流标签的定义和使用规范,分析了流标签在两种主要体系结构中对QoS如何支持,并用实际数据分析表现出流标签对于传统协议更能较好的支持QoS。