A Simple One-pot Synthesis of Indeno[2,1-f]quinolin-3-one Derivatives under Microwave Irradiation

A series of new indeno[2,1‐f]quinolin‐3(2H)‐one derivatives were synthesized by a reaction of aromatic aldehyde with Meldrum's acid (2,2‐dimethyl‐1,3‐dioxane‐4,6‐dione) and 9H‐fluoren‐2‐amine under microwave irradiation without catalyst in glacial acetic acid. This reaction has notable advantages of short reaction time, high yield and convenient operation.     

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.     

TCP/IP协议及其安全性分析

介绍TCP／IP协议内容，以及TCP／IP中协议的功能IP，TCP，UDP，ICMP；并详细介绍了提高TCP／IP协议中网络层、传输层、应用层安全性的方法。     

高速网络TCP/IP减荷的研究

近十年来,随着网络技术的发展,网络带宽迅速增长,而同期CPU的性能未得到相应的提高.在吉比特网络下,网络终端CPU处理TCP/IP协议的能力已经成为限制网络应用的瓶颈.为了使终端用户能充分利用广阔的带宽资源,需要提高网络终端的协议处理能力.文中基于FPGA的硬件设计,将原来由软件完成的IP层协议功能完全卸载出来,向CPU提供硬件支持.并且通过功能仿真、综合后仿真、布局布线后仿真验证了设计的可行性,由静态时序分析可知,协议处理器的时钟频率可达50 MHz,处理IP数据流的能力可以达到1.6 Gb/s的网络线速度.     

基于MPLS的VPN技术原理

随着Internet的蓬勃发展，人们对其应用提出了更高的要求。但Internet缺乏有效的流量和网络带宽管理手段，经常会发生阻塞。无法对服务质量(QoS)提供保证，许多应用对于目前的IP技术(如语音和视频等)显得力不从心。而新兴的多协议标记交换技术(MPLS：Multi Protocol Label Switching)有望解决这一问题。     

基于GPRS与X.25网络的数据传输

分析了GPRS网络的特点和以往数据传输设备存在的缺陷,介绍了GPRS网络在数据传输中的优势和特点,讨论了GPRS的网络结构、协议模型和路由管理的问题.介绍了如何利用GPRS实现与X.25网络的数据传输.最后对其应用前景进行了展望.     

下一代光网络的发展和关键技术

近年来，随着经济的发展和计算机的普及，Internet业务出现了爆炸性的增长，现有的网络应付大量的数据业务和各种类型的服务业务已显得有些力不从心。为了适应未来发展的需求，并针对IP业务的主导地位和光传输技术的发展，下一步不仅要提高传输链路的带宽和利用率，还要提高光网络的智能性，以满足IP业务对传输和交换系统的要求。因此我们提出发展以IP层和光层融合的下一代智能光网络（OTN）。并针对下一代光网络的发展和关键技术进行了简单的阐述。     

Strand空间中基于安全密钥概念的证明思路

提出了Strand空间模型中证明安全协议的一个新思路,它从安全密钥的概念出发,参照基于理想概念的证明方法,得出证明所需的预备结论,从而对协议的秘密属性与认证属性进行证明。此外,还给出了一个针对Yahalom-BAN协议安全性的证明实例,从中可以看到该思路非常适于采用对称加密体制且具有密钥分发功能的三方认证协议的证明,并且它还使得证明过程简洁而直观。     

A comparison of different paging mechanisms for mobile IP

This paper proposes two Individual paging schemes, then presents a comparative analysis on the signaling cost functions of Mobile IP (MIP) with different paging protocols and paging schemes and investigates constructing optimal paging areas using discrete system model as a mobility model. In wireless mobile Internet, mobile hosts often visit foreign networks that might be far away from their home networks and the occurrences of their inter-domain movement are relatively rare. In this scenario, our analytical results show that paging, particularly individual paging, can significantly improve the total signaling cost of MIP. We show that Domain paging can bring about considerable cost saving compared to FA (Foreign Agent) paging. Our results also demonstrate the significant advantages of Individual Paging over Static Aggregate Paging. The results show that specifying the optimal paging area size is critical in saving signaling cost of MIP with paging support. Hung Tuan Do received the B.E. degree in Electrical Engineeing and Computer Science from Hanoi University of Technology, Vietnam, and the M.E. and the Ph.D. both from Gunma University, Japan. His research interests include Mobility Management, Wireless Internet and Mobile Ad hoc Networks. Yoshikuni Onozato is a Professor with Gunma University. His research interests are in satellite systems, computer communication networks and distributed computing systems and span the entire spectrum from the design and performance evaluation of these systems to their implementation. He is a member of IEEE, ACM, IPSJ, ORSJ and IEICE.     

Petri net model of protocol conversion for CTF service: its universal coupling criteria and property analysis

Protocol conversion is a critical issue requiring much research attention. In this paper, the protocol conversion methodology proposed originally by Green is extended with the Petri nets theory to study application layer protocol conversion among more than two interfaces. The click‐to‐fax (CTF) service based on the Internet intelligent network (IIN) model is taken as an example to illustrate the extended part. A two‐step Petri net modelling method is proposed, which is easier compared to constructing the overall model directly in just one step. Universal coupling criteria of Petri net model of protocol conversion (PNPC) are abstracted. The PNPC of CTF service is analysed using analytical techniques of Petri nets, which are proved to be effective in finding and eliminating potential bugs. The necessity of the concept of service layer is also emphasized. Copyright © 2006 John Wiley & Sons, Ltd.