In this chapter, you will learn one type of virtual private network architecture: the MPLS-based VPN, and in particular, a Layer 2 VPN (L2VPN). We’ll also briefly look at using PPTP over DSL for ...remote access, another type of arrangement that is often considered a VPN.
You will learn how an L2VPN can make CE1 and CE2 appear to be connected by a single LAN, creating a virtual private LAN service (VPLS) between them. We’ll also configure a complete VPLS based on L2VPNs.
It is very important to learn the operation and the management of a server computer from not only lecture but also experience. In the department of Electronics and Information Engineering, ..."Construction experiment of the network server", using the laboratory LAN system was carried out as a theme of the student experiment for the fourth grade. The WWW server and the Mail Server, which were often used in the Internet, were con figured after the installation of the operation system Linux. An open lecture on "Introduction to the home network" for citizens was given referring to the student experiment. Configuration of several servers related to the multimedia was performed in the open lecture. This paper describes the details of these two practical experiments.
This paper describes the necessary of the remote monitoring system for energy-saving streetlight. The system consists of streetlight energy-saving control system, cable anti-theft system, wireless ...communication network, remote monitoring platform, database server, network server and specific end-users. In general, the design of the system is based on the network and database technology. The software of the system is based on B/S Model and uses the embedded database technology and IIS information services. In addition, the system can control each light individually, reduce electricity resource wasting and increase utilization ratio of streetlight. The system has better real-time performance and effectiveness than the common streetlight monitoring system.
To attain a performance improvement obtained from an effi cient operation of the network server is one of themost important objectives of the system construction and maintenance.For such purposes a ...variety of benchmark programs and analytical tools on an application level has beendeveloped.On the other hand, many benchmark programs have also been developed for each hardware as the systemcomponent, such as CPU's, memories, networks, disk-drives and so forth.However, most of the effi ciency measurement results so far published have been those which were tested froman application performance point of view on an average concept and very few of them have been those derivedfrom testing of the performance limit of the component of hardware.This study is concerned with a measurement of the performance limit of component of hardware and itscomparison with theoretical values which are calculated from the data sheet.Thus, the adequacy of such test methods is examined.In the next step the performance is measured in an environment, where each component of hardware reachesits performance limit and fi nally, a method of technique, which may help the system attain an overall optimumeffi ciency, is proposed.
In this paper, we have created VoIP terminals that use virtual private network (VPN) to eliminate security risks due to the complexity of protocols involved and network equipments used. ...Point-to-point tunneling protocol (PPTP) is used on the session initiation protocol (SIP) stack, which is enabled by Internet telephony terminal to test its performance and feasibility. To measure the performance of call quality, we have built the experiment environment and observed that the delay caused by encapsulation between internet and VoIP telephones is under 8 ms at most. The major delay is assumed the time required to capsulate the packet for tunneling of VPN. Because the difference of average delay time is under 4 ms~5 ms, the difference of call quality between VoIP and VoIP telephone adopting VPN is negligible. We have concluded that the capsulation process between PPTP access concentrator (PAC) and PPTP network server (PNS) is the major factor influencing the network load by changing the number of fames in a packet during communication. Also, we have concluded that the most suitable frame numbers is two or three by adding the frame numbers in a packet to obtain the suitable frames in a packet and setting up end to end delay to be 160 ms~170 ms. We have suggested, developed, and evaluated an internet telephony system that implements secure user authentication and data transmission. Through measuring the delay time between a conventional VoIP telephone and the proposed system, the quality of call made through the proposed system and its' feasibility are discussed.
This paper presents the design and implementation of a user-level real-time network system in Real-Time Mach. Traditional network systems for microkernel based operating systems, which tend to focus ...on high performance and flexibility, are not suitable for real-time communication. Our network system provides a framework for implementing real-time network protocols which require to bound protocol processing time, and it is suitable for implementing on microkernel based operating systems. In this paper, we especially focus on the aspects to avoid the priority inversion problem in order to make network systems more preemptable and predictable. We also describe the feasibility of our network system for building distributed multimedia systems.
In this paper, the Internet-based automation equipment intelligent monitor system is researched. It focuses on the ARM9 and Ethernet interface method, CAN/Ethernet protocol conversion and terminal ...building. Terminal mainly includes monitoring interface and Web database. The experiment results show that the system meets the accuracy, real-time and reliability of automatic maintenance equipment. And it implements effectively the remote monitoring.
Blockchain, as the underlying technology of crypto-currencies, has attracted significant attention. It has been adopted in numerous applications, such as smart grid and Internet-of-Things. However, ...there is a significant scalability barrier for blockchain, which limits its ability to support services with frequent transactions. On the other side, edge computing is introduced to extend the cloud resources and services to be distributed at the edge of the network, but currently faces challenges in its decentralized management and security. The integration of blockchain and edge computing into one system can enable reliable access and control of the network, storage, and computation distributed at the edges, hence providing a large scale of network servers, data storage, and validity computation near the end in a secure manner. Despite the prospect of integrated blockchain and edge computing systems, its scalability enhancement, self organization, functions integration, resource management, and new security issues remain to be addressed before widespread deployment. In this survey, we investigate some of the work that has been done to enable the integrated blockchain and edge computing system and discuss the research challenges. We identify several vital aspects of the integration of blockchain and edge computing: motivations, frameworks, enabling functionalities, and challenges. Finally, some broader perspectives are explored.
