共查询到19条相似文献,搜索用时 109 毫秒
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本文讨论了校园网环境下外网用户访问内网非直通主机的有关问题,提出了一种解决方案。该方案利用校内的GATE服务器作为桥梁解决了外部用户的接入问题,实践效果表明该方案可以使得外部用户成功接入校园网。 相似文献
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提出一种利用B/S架构设计的智能家居远程控制系统的设计。将智能家居系统控制主机接入互联网,在控制主机上架设网站,用户可以利用网站对连接到主机的USB设备进行操作,从而通过USB设备控制家庭内的智能家居。该系统利用了B/S架构的优点,用户能够很方便地对家庭智能家居系统进行远程控制。 相似文献
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路由器POS接入解决方案 总被引:1,自引:0,他引:1
深圳华为技术有限公司 《现代电信科技》2002,(8):55-56
销售点(POS)接入本身并非什么新概念.用户在POS终端上刷卡,POS终端将获得的信息(卡号、业务数据等)通过通信线路传给银行主机,主机对信息进行处理,并向POS终端返回相应的处理结果,于是完成一笔交易.在POS终端和银行的主机之间就必须有POS接入设备来完成双方的通信.相应地,POS接入设备和解决方案的提供也就成为一个颇具规模的市场. 相似文献
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DHCP及Option82安全机制的原理与实现 总被引:2,自引:0,他引:2
动态主机配置协议(DHCP)主要用来动态提供配置参数给因特网上的主机,一方面从DHCP服务器传送主机特定的协议配置参数到主机,同时自动分配网络地址给主机。目前本地局域网大多使用高速公共因特网接入技术和高速调制器,并使用动态主机配置协议分配用户的主机地址。然而,大量的公用主机地址的使用,也会引进安全问题。本文针对目前在局域网普遍使用的DHCP及其为解决安全问题而引进的Option82机制作了简单的描述,并具体阐述其在IPDSLAM的一种具体实现方式。 相似文献
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基于用户公平的随机早期检测算法改进 总被引:3,自引:1,他引:2
边界路由器通常为多个接入用户提供访问Internet的共享上行链路,当所有用户的接入带宽大于上行链路带宽时,可能产生拥塞。在这种典型接入方式下,存在基于用户的公平性问题:一旦边界路由器发生拥塞,各接入用户在共享链路上所获得的吞吐率应该与接入带宽成正比。对不同接入带宽用户的吞吐率进行了理论分析和仿真实验,结果表明,随机早期检测算法(RED)不能提供较好的用户公平性服务,针对这一问题,对RED算法的丢包概率的计算进行了改进:在计算某一个包的丢弃概率时,根据其输入接口的链路带宽进行修正。仿真结果表明,改进的算法在解决基于用户公平性方面具有良好效果。 相似文献
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黄东 《电子产品维修与制作》2009,(24):109-110
某校园网有近3000个用户主机接入,但同时在线的用户主机最多时在1000左右,出口流量一般在70~100M/s,流量大时可达到120多M/s。由于学校申请了8个教育网C网的IP,如果每台电脑分配一个IP就不够用,所以学校教学楼、办公楼分配了从教育网申请的IP,学生机房、家属院和学生宿舍分配了私有IP。该校校园网未改造之前的网络结构如图1所示。 相似文献
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移动IP作为Internet的移动接入技术,为大范围内慢速的漫游提供了移动性支持。蜂窝IP解决了无线接入Internet主机频繁移动性问题。弥补了移动IIP的不足,为基于小区的快速频繁的移动提供了有效支持,二的结合能有效地支持全球范围内的主机的移动性。本介绍了这两种协议 ,并对它们的网络实体和关键技术进行了探讨和分析。 相似文献
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为了实现为不同接入等级用户提供不同紧急程度的接入服务,保证高优先级用户的优先接入。TD-SCDMA系统提供了接入等级控制机制。通过使用接入等级、接入服务等级、坚持度检查、UpPCH子信道分配等机制,TD-SCDMA系统实现了用户的接入优先级控制。本文从理论和实际的角度对此机制进行了分析,并进行了仿真验证,仿真结果表明该机制能有效实现不同优先级用户的接入优先级控制。 相似文献
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1 IntroductionTheAccessNetworkisaseriesoftransferenti tiesbetweenservicenodeinterfacesandtherespon dentusernetworkinterfaces,providingtransfer ring ,multiplexer,cross connectionandotherloadtelecommunicationservices[1 ] .AstheCommunica tionTechnologiesdevelop… 相似文献
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Support for host mobility an essential and necessary feature for roaming users who connect to wireless networks via access
points. Access points may have different capabilities, be connected to different networks and be installed by different providers.
A mobile host will discover multiple access points in this environment. In such an environment, a mobile host should be able
to use the best available connection to communicate with a correspondent host and perhaps use multiple connections for different
hosts. In areas with wireless local area network access, pockets with limited or no coverage could exist. Such restricted
connectivity could be compensated by neighbor hosts who form an ad hoc network and relay packets until they reach an access
point. This paper describes and discusses a proposed solution towards enabling and supporting connectivity in wireless networks.
In the proposed solution the network layer software will evaluate and decide which wireless network connections to use. A
Running Variance Metric (RVM) and a Relative Network Load(RNL) are used to measure the traffic load of access points in wireless access networks. RVM and RNL can be efficiently used
for both infrastructure networks and ad hoc networks. Multihomed Mobile IP (M-MIP) is an extension of Mobile IP that enables
mobile hosts to use multiple care-of addresses simultaneously. The extension enhances network connectivity by enabling the
mobile host, the home agent and correspondent hosts to evaluate and select the best connection. A proposed gateway architecture
using M-MIP that integrates wired IP networks with ad hoc networks is described. The M-MIP and gateway architecture using
the RVM and RNL metrics have been validated with simulation studies and results are presented. 相似文献
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Designing a solution for multihop cognitive radio networks poses several challenges such as the realization of the control channel, the detection of primary users, and the coordination of secondary users for dynamic spectrum access purposes. In this article we discuss these challenges and propose a solution that aims to meet most of them. The proposed solution is completely distributed, and does not need dedicated spectrum resources for control purposes, but rather leverages on a virtual control channel that is implemented by having users exchange control information whenever they meet in a particular channel, using network coding techniques for better dissemination performance. Due to these aspects, our proposal represents a significant improvement over existing dynamic spectrum access and multichannel MAC solutions. We discuss the effectiveness of our scheme in multihop cognitive ad hoc networks, where secondary users need to opportunistically access the spectrum at those locations and times at which it is not used by primary users. Finally, we report the results of an evaluation study assessing the performance of the proposed scheme with respect to different system and scenario parameters. 相似文献
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Internet网络环境中认证与密钥分配的研究 总被引:11,自引:0,他引:11
本文根据ISO制定的OSI安全结构,提出了一种解决intranet安全性问题的全面安全模式,并设计了一个适用于Internet环境的认证与密钥分配协议;新协议采用分层机制,在低层利用intranet本地网的已有认证与密钥分配协议,在高层则采用双钥密码体制来设计跨intranet的认证与密钥分配协议。新协议与已有密码协议有很好的兼容性,且不降低原协议的安全性,并为in-tranet的各种远程访问提供安全保护,有利于网络的安全管理 相似文献
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Dynamic bandwidth allocation for quality-of-service over Ethernet PONs 总被引:24,自引:0,他引:24
Assi C.M. Yinghua Ye Sudhir Dixit Ali M.A. 《Selected Areas in Communications, IEEE Journal on》2003,21(9):1467-1477
Ethernet-based passive optical network (EPON) technology is being considered as a promising solution for next-generation broadband access networks due to the convergence of low-cost Ethernet equipment and low-cost fiber infrastructures. A major feature for this new architecture is the use of a shared transmission media between all users; hence, medium access control arbitration mechanisms are essential for the successful implementation of EPON: i.e., to ensure a contention-free transmission and provide end users with equal access to the shared media. We propose to use the multipoint control protocol defined by the IEEE 802.3ah task force to arbitrate the transmission of different users, and we present different dynamic bandwidth allocation (DBA) algorithms to allocate bandwidths effectively and fairly between end users. These DBA algorithms are also augmented to support differentiated services, a crucial requirement for a converged broadband access network with heterogeneous traffic. We show that queueing delays under strict bandwidth allocation algorithms result in an unexpected behavior for certain traffic classes, and we suggest the use of DBA with appropriate local queue management to alleviate this inappropriate behavior. We conduct detailed simulation experiments to study the performance and validate the effectiveness of the proposed protocols. 相似文献
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针对动态IP地址配置方式下出现的伪DHCP对校园网用户的影响问题,研究了DHCP的工作原理,剖析了伪DHCP影响校园网用户的原因,提出了通过调整网络结构并利用访问控制列表和PVLAN等技术联合解决问题的方案. 相似文献
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为了解决既能在异地访问内网资源,又能充分保证内网资源的高度安全,将VPN与DMZ技术应用于校园网络的升级改造。提出了针对DMZ专区的三类IP地址映射算法与合法外网用户通过VPN访问内网资源需要的虚拟IP地址转换函数,并在此基础上提出了VPN与DMZ技术在校园网上集成应用的解决方案。通过在校园网中合理构建DMZ专区与VPN网络,巧妙设置DMZ与VPN的访问规则,在充分保证校内资源安全的前提下,成功解决了异地用户共享内网资源的难题。 相似文献