计算机网络介绍中英文

计算机网络基础介绍（英文）
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Introduction to Computer Network
Computer network is a system connecting two or more computers. A computer network allows user to
exchange data quickly, access and share resources including equipments, application software, and
information.
Data communications systems are the electronic systems that transmit data over communications lines
from one location to another. You might use data communications through your microcomputer to send
information to a friend using another computer. You might work for an organization whose computer
system is spread throughout a building, or even throughout the country or world. That is, all the parts—
input and output units, processor, and storage devices—are in different places and linked by
communications. Or you might use telecommunications lines—telephone lines—to tap into information
located in an outside data bank. You could then transmit it to your microcomputer for your own reworking
and analysis.
To attach to a network, a special- purpose hardware component is used to handle all the transmission.
The hardware is called a network adapter card or network interface card (NIC), it is a printed circuit board
plugged into a computer's bus, and a cable connects it to a network medium.
Communications networks differ in geographical size. There are three important types: LANs, MANs, and
WANs.
Local Area Networks Networks with computers and peripheral devices in close physical proximity—within
the same building, for instance—are called local area networks (LANs). Linked by cable-telephone,
coaxial, or fiber optic. LANs often use a bus form organization. In a LAN, people can share different
equipments, which lower the cost of equipments. LAN may be linked to other LANs or to larger networks
by using a network gateway. With the gateway, one LAN may be connected to the LAN of another LAN of
another office group. It may also be connected to others in the wide world, even if their configurations are
different. Alternatively, a network bridge would be used to connect networks with the same
configurations.
There is a newly development for LANs: WLAN. A wireless LAN (WLAN) is a flexible data communication
system implemented as an extension to, or as an alternative for, a wired LAN within a building or campus.
Using electromagnetic waves, WLANs transmit and receive data over the air, minimizing the need for
wired connections. Thus, WLANs combine data connectivity with user mobility, and, through simplified
configuration, enable movable LANs.
Over the recent several years, WLANs have gained strong popularity in a number of vertical markets,
including the health-care, retail, manufacturing, warehousing, and academic arenas.

These industries have profited from the productivity gains of using hand-held terminals and notebook
computers to transmit real-time information to centralized hosts for processing. Today WLANs are
becoming more widely recognized as a general-purpose connectivity alternative for a broad range of
business customers.
Applications for Wireless LANs Wireless LANs frequently augment rather than replace wired LAN
networks—often providing the final few meters of connectivity between a backbone network and the
mobile user. The following list describes some of the many applications made possible through the power
and flexibility of wireless LANs:
●Doctors and nurses in hospitals are more productive because hand-held or notebook computers with
wireless LAN capability deliver patient information instantly.
●Consulting or accounting audit engagement teams or small workgroups increase productivity with
quick network setup.
●Network managers in dynamic environments minimize the overhead of moves, adds, and changes with
wireless LANs, thereby reducing the cost of LAN ownership.
●Training sites at corporations and students at universities use wireless connectivity to facilitate access
to information, information exchanges, and learning.
●Network managers installing networked computers in older buildings find that wireless LANs are a
cost-effective network infrastructure solution.
●Retail store owners use wireless networks to simply frequent network reconfiguration.
●Trade show and branch office workers minimize setup requirements by installing preconfigured
wireless LANs needing no local MIS support.
●Warehouse workers use wireless LANs to exchange information with central databases and increase
their productivity.
●Network managers implement wireless LANs to provide backup for mission-critical applications
running on wired networks.
●Senior executives in conference rooms make quicker decisions because they have real-time
information at their fingertips.
The increasingly mobile user also becomes a clear candidate for a wireless LAN. Portable access to
wireless networks can be achieved using laptop computers and wireless NICs. This enables the user to
travel to various locations–meeting rooms, hallways, lobbies, cafeterias, classrooms, etc.–and still
have access to their networked data. Without wireless access, the user would have to carry clumsy
cabling and find a network tap to plug into.

Metropolitan Area Networks These networks are used as links between office buildings in a city. Cellular
phone systems expand the flexibility of MAN by allowing links to car phones and portable phones.
Wide Area Networks Wide area networks are countrywide and worldwide networks. Among other
kinds of channels, they use microwave relays and satellites to reach users over long distances. One
of the most widely used WANs is Internet, which allows users to connect to other users and
facilities worldwide.
计算机网络基础介绍（译文）
计算 机网络是连接两个或多个计算机的系统，它允许用户快速地交换数据，访问和共享包括设备、应用软
件和 信息在内的资源。
数据通信系统是通过通信线路将数据从一个地方传送到另外一个地方的电子系统。你 可以使用数据通信通
过你的微机将信息发送给使用另外一台机器的朋友。你有可能在为一家公司工作，其 计算机系统遍布一座
大楼，或者甚至是全国乃至世界。也就是说，所有的部分——输入和输出单元、处理 器和存储设备——都
在不同的地方，是通过信息连接起来的。或者你可能使用远程通信线——电话线—— 接进位于外部数据单
元的信息。然后你可能将信息传送到自己的微机上用于重新工作和分析。
为了连接到网络上，需要使用特殊用途的硬件部件来处理所有的传送。这个硬件被称为是网络适配卡或网
络接口卡，它是插入到计算机总路线上的印刷电路板，由电缆将它连接到网络介质。
通信网络由于其占据的地理范围大小而不同。有三种重要的类型：局域网、城市网和广域网。
局域网 计算机和外部设备在很近的物理范围内的网络被称为是局域网，例如在一座大楼内，由电缆链接 —
—电话线、同轴电缆或光缆。局域网通常使用总线型的结构。在局域网中人们可以共享不同的设备，这 样
可以降低设备的费用。局域网可以通过使用网关连接到另外一个局域网或者更大的网。使用网关，一个 局
域网可以被连接到另一个办公团体的局域网，它也可被连接到世界范围的其他局域网上，即使它们的配 置
不同。另外一种方法是用网桥来连接具有相同配置的网络。
对于相同局域网有一个新开发的 网络：无线局域网。无线局域网是灵活的数据传输系统，实现了大楼或校
园内有线局域网的延伸或替换。 无线局域网使用电磁波通过空气传送和接收数据，最低限度地减少了有线
连接。这样，无线局域网把数据 连接和用户移动性结合起来，通过简化的配置，形成了移动的局域网。
随着近几年的发展，无线局域网 在一些市场领域已经获得了广泛的普及，其中包括健康保健、零售业、制
造业、仓储业和学术界。这些工 业通过手提终端和笔记本电脑将实时信息传送到中央主机进行处理，从获
得的生产率中已获益百浅。如今 ，对于广泛的商业客户来说，无线局域网正成为公认的通用连接的替代品。
无线局域网的应用 无线局 域网通常是增加而不是代替有线局域网的功能——通常是在中枢网络和移动用
户间提供最后几米的连接。 通过无线局域网的灵活性和功能，以下所列描述了可能实现的许多应用当中的
一些：
●医院的 医生和护士利用手提或笔记本电脑与无线局域网连接的性能，及时传递了病人的信息，提高了效
率。

●顾问或会计审计事务组或一些小的工作组使用快速搭建的网络提高了工作效率。
●在动态环 境下的网络管理者使用无线局域网最大限度地减少了经常的移动、添加和修改工作，从而降低
了局域网所 有者的费用。
●公司的培训点和大学的学生使用无线连接便于访问信息，进行信息交换以及学习。
●在旧的建筑物内安装网络计算机的网络管理员发现无线局域网是划算的网络基础结构的解决方案。
●零售商店的老板使用无线局域网简化经常性的网络重新配置(问题)。
●贸易展览部门工作 人员通过安装预先配置的无线局域网最大限度地降低了配置需求，而不需要当地信息
管理系统的支持。
●仓储工人使用无线局域网和中心数据库交换信息提高了生产率。
●网络管理员使用无线局域网提供运行在有线网络上的关键应用程序的备份。
●在会议室的高级行政官因为播送有实时信息可供使用，因此可以做出快速的决定。
日益拉长 的移动用户也成为无线局域网的坚实的后备力量。使用膝上电脑和无线网络接口卡就可实现移动
访问无线 局域网，这就使得用户可以在不同的地方穿梭——会议室、门厅、休息室、自助食堂、教室等地
方——仍 然可以访问其网络数据。假如没有无线局域网，用户就不得不携带笨重的电缆寻找网络插头。
大城市网 这些网络用于一个地市内的建筑物之间的连接。移动电话系统通过允许将汽车电话和移动电话接
入而扩展 了大城市网的灵活性。
宽域网 宽域网是国家和世界范围内的网络。在其他的信道种类中，宽域网使用 微波中继和卫星通信远距离到
达用户。使用最广泛的宽域网是Internet，它允许在世界范围内用 户和用户及设备的连接。
1.
Researches on Some Problems of Network Security Service in Large Dynamic
Multicast System
大型动态组播系统网络安全服务的若干问题研究
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2.
IPSec (Internet protocol security) is a IETF standard network security protocol to
provide transparent security service for IP network communication, to protect
TCPIP communication from wiretapping and juggle, to withstand the attack of
networks, to maintain facility at the same time, and provide strong security
guarantee for the implement of VPN client system.

IPSec(Internet安全协议)是一个IETF标 准网络安全协议,为IP网络通信提供透明的安全服务,
保护TCPIP通信免遭窃听和篡改,可以有效 抵御网络攻击,同时保持易用性,并为VPN客户端
系统的实现提供了强有力的安全保障。
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3.
The

key technologies of NGI are addressed, referring

to network scalability, networkavailability, network manageability, network security,
QoS control, and IPv6 technologies.

文章重点探讨了下一代互联网的关键技术: 网络可扩展技术、网络可用性技术、网络管理控
制技术、网络安全技术、服务质量(QoS)业务控制技 术和IPv6技术。
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4.
After analysing the distributed power monitoring system, this paper provides an
integrated safety service, including solution to the certificate authority, distributed
monitoring station and the whole link layer safety issues.

本文在分析电力监控系统特点的基础 上为监控网络提供了一个完整的安全服务,该服务包括
对安全认证中心、各个分布式监控站点和整个网络 传输过程中安全问题的考虑。
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5.
IP Security Protocol (IPSec) is the standard security IP protocols defined by
theInternet Engineering Task Force (IETF) , and it provides cryptographically-based
security at network layer .

IP安全协议IPsec是IETF制定的安全IP协议建议标准，在网络层 提供基于密码学的安全服
务。
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6.
Network security includes a series network security technique that fireproofing wall
is representation. Those are IP address transition technique, service deputy,
dummy special network technique, system separating inner net and outer net, and
so on.

网络安全技术包括以防火墙技术为代 表的系列网络安全技术，即IP地址转换技术、服务代
理技术、虚拟专用网络技术、将系统分为内网同外 网等。
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7.
It furnishes management seeking and technology support of EIP, Business
Cooperation, Information Plat,Video Conference System and Internet Security
Products and so on.

定向为政府和大中型企业提供网络信息化整体解决方案，包括电子政务、协同商务、信 息平
台、视频会议、网络安全等全方位管理咨询和技术服务。
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8.
The experimental data show that the prototyping system can provide
active,transparent and efficient information security service.

实验数据分析表明:所设计的信息安全服务机制,可对 网络中的应用系统提供主动式、透明、
高效的信息安全服务。
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9.
At current, the only infrastructure that crm afford trust and security service is the
public key infrastructure (PKI) that will disscussed in this paper.

目前在网络空间中能提供信任和安全 服务的基础设施就是本文将要讨论的公开密钥基础设
施(PKI)。
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10.
This paper discusses the design idea of the architecture of EFT network in terms
of requirement of EFT in data security, and describes how the security service and
mechanism are used to implement data security of EFT system in the
architecture.

本文根据EFT系统对数据安全的要求,讨论了EFT 网络体系结构的设计思想,以及在这样的
体系结构下,如何利用安全服务、安全机制来保证EFT系统的 数据安全

Computer network security and to guard against
计算机网络安全防范


Abstract: When mankind entered the 21st century information society, the
network society of the time, China will establish a complete set of network
security system, especially from the policy and law to establish China's own
characteristics, network security system.
文摘:在人类进入二十一号世纪的信息社会,网络社会道德危机的时候,中国将建立 一套完整的网
络安全体系,特别是法律与政策,建立中国自己的特点、网络安全系统。

Key words: computer; network; security; prevent
关键词:计算机、网络;安全;防止

In the information age, information can help groups or individuals so that they
benefit from, the same information can also be used to pose a threat to them,
caused damage. Therefore network security, including the composition of
network hardware, software and network transmission of information security,
so that they do not because of accidental or malicious destruction of the
attacks, network security not only the technical aspects, but also management
issues, both complement each other, are indispensable. 在信息时代,信息能够帮助团体或个人,使他们受益于同样的信息也可以被用来威胁他们,造成的
损 害。因此,网络安全,包括组成的网络硬件、软件和网络传输的信息安全,这样他们就不会因意
外或蓄意 破坏攻击,网络安全技术方面不仅,而且管理问题,两者相辅相成,是必不可少的。

First, the concept of computer network security
International Organization for Standardization of
as:
management of security protection, the protection of computer hardware,
software, data is not due to accidental and malicious destruction of reasons,
change and leakage.
physical security and logical security of both the contents of the contents of the

logic of security could be understood as we often say that the information
security, information refers to the confidentiality, integrity and availability of
protection, and network security Information security is the meaning of the
extension, that network security is a network of information confidentiality,
integrity and availability protection. Computer network security as the specific
meaning of the user changes, the user is different on the network security
awareness and requirements will be different. From the ordinary user's point of
view, could only hope that personal privacy or confidential information
transmission on the network be protected against eavesdropping, tampering
and forgery; and network provider in addition to care about these network
information security, we must also consider how to deal with sudden natural
disasters, such as military strikes against the destruction of network hardware,
as well as unusual in the network how to restore network communications, and
maintain the continuity of network communications.
第一,计算机网络安全的概念
国际标 准化组织对“计算机安全”定义为:“建立一个数据处理系统所采用的技术和管理的安全保
护,保护计算 机硬件,软件,数据不是由于偶然的、蓄意破坏原因,改变和泄漏。”上述定义的计算
机安全包括物理安 全、逻辑安全双方的内容的内容的逻辑可以被理解为安全我们常说,信息安全
是指,信息的保密性,完整 性和可用性保护,而信息安全是网络安全的意义,网络安全扩展是一个
网络信息的保密性,完整性和可用 性的保护。计算机网络安全中的具体意义的变化,是用户不同用
户在网络安全意识和要求也有所不同。从 普通用户的角度来看,只能希望个人隐私或机密信息的
传输在网络上被保护防止窃听,捣弄和伪造的;以 及网络提供商除了关心这些网络信息安全,我们
也必须考虑如何处理突发的自然灾害,如军事打击网络硬 件的破坏,以及不寻常的在网络中如何
恢复网络通信,维护网络通信的连续性。

In essence, the network security, including the composition of network
hardware, software and network transmission of information security, so that
they do not because of accidental or malicious attacks on the destruction of
both the technical aspects of network security issues, there are management
issues, the two sides complement each other, are indispensable. Man-made
network intrusion and attacks makes network security is facing new
challenges.
在本质上,网 络安全,包括组成的网络硬件、软件和网络传输的信息安全,这样他们就不会因意外
或恶意攻击破坏两个 技术方面的网络安全问题,还有管理问题,双方相互补充,是必不可少的。人
造网络入侵和攻击使网络安 全面临新的挑战。

Second, computer network security status quo
Computer network security is the network hardware, software and data
systems are protected from accidental or malicious destruction of reasons,
alteration, disclosure, the system continuous, reliable, normal operation of
network services without disruption. Computer and network technology has the
complexity and diversity, makes computer and network security has become a

need to continue to update and improve the area. At present, hackers method
has been more than the type of computer virus, and many attacks are fatal. In
the Internet network, because the Internet does not have the time and
geographical constraints, whenever there is a means to generate new attacks,
we can in a week around the world, these attacks means the use of network
and system vulnerabilities to attack computer systems and resulting in network
paralysis. Worms, backdoor (Back-doors), Rootkits, DOS (DenialofServices)
and Sniffer (network monitor) is a familiar means of several hacker attacks.
However, none of these attacks means they reflect the astonishing power of
today become worse. These types of attacks means the new variant, with
previous attacks appeared methods, more intelligent, targeted against
Internet-based protocols and operating system level. From the Web process
control procedures to the kernel-level Rootlets. Hackers practices escalating
renovation, to the user's ability to guard against information security challenge.
第二,计算机网络安全的现状
计算机网络安全是网络硬件、软件、 数据系统受到意外或蓄意破坏原因、变更、信息披露制度、
连续、可靠、系统正常运行的网络服务没有中 断。计算机及网络技术的复杂性和多样性,使计算
机和网络安全已成为一个需要不断更新和改进的区域。 目前,黑客方法已超过一种型号的电脑病
毒,和许多攻击是致命的。在互联网络,因为,互联网也不会有 时间和地域限制,每当有一种手段来
产生新的袭击一个星期,我们会在世界各地,这些攻击是指利用网络 和系统漏洞攻击电脑系统和
导致网络瘫痪。蠕虫、秘密(Back-doors),Rootkits、 DOS(DenialofServices)和嗅探(网络监控)
是一种常见的几种方式遭到黑客攻击 。然而,所有这些袭击意味着他们反映了惊人的力量的今天
变得更糟。这些类型的攻击手段,新变种先前 袭击出现方法,更聪明,有针对性的对网络协议和操
作系统级。从网络过程控制程序到内核级Rootl ets。黑客升级改造、实践能力,对用户的防范信
息安全的挑战。


Third, computer network security precautions
1, to strengthen the internal network management and the use of safety
awareness among staff, many computer systems commonly used passwords
to control access to system resources, which is anti-virus process, the most
vulnerable and the most economical methods. Network administrator and
terminal operator privileges in accordance with their responsibilities, choose a
different password for the application data legitimate operation, to prevent
unauthorized users to access the data and the use of network resources.
On the network, software installation and management is crucial, it is not only
related to network maintenance and management efficiency and quality, but
also to the network security. A good antivirus software can be easily installed
within minutes to the organization each NT server can also be downloaded
and spread to all the purpose of the machine by the network administrator set
up and manage to focus, it will work with the operating system and other

security is closely linked to become a part of network security management,
and automatically provide the best network virus defensive measures. When
the computer virus on-line resources applications attack, such as the virus
exists in the information-sharing network of media, it is necessary to the
security at the gateway, on the network front- end for antivirus.
第三,计算机网络安全措施
1、加强内部网络管 理和使用安全意识在职员中,许多计算机系统常用的密码控制访问系统资源,
是病毒的过程中,最易受伤 害的,最经济的方法。网络管理员及终端操作员特权依照他们的职责,
选择不同的密码的应用数据合法运 作,防止未经授权的用户访问数据和网络资源的使用。
在网络上,软件安装和管理至关重要,它不仅涉 及到网络维护和管理效率和质量,同时也给网络安
全。一个好的杀毒软件可以很容易地安装在几分钟之内 组织每一个NT服务器也可以下载并扩散到
所有的目的的机器由网络管理员建立和管理集中精力,它会工 作的操作系统和其他安全息息相关,
成为网络安全管理,并自动提供最佳的网络病毒防御措施。当计算机 病毒攻击网上资源应用,如病
毒存在于网络媒体的信息共享,有必要对安全网关,在网络上的前端进行杀 毒。


2, network firewall technology
Is a kind of used to strengthen the network access control to prevent the
external network users to illegal means to enter the external network through
the internal network, access internal network resources and protect the
internal network operating environment special for Network Interconnection
Devices. It is between two or more networks such as packet transmission link
in accordance with a certain degree of security strategy to implement the
inspection, to determine whether the network communication between are
allowed to, and monitor the network running. Although the firewall is to protect
the network from an effective means of hacking, but there are obviously
inadequate: through the firewall can not protect against outside attack other
means, can not prevent defectors from the inside and inadvertent threats
posed by users, but also can not completely prevent the transmission of the
virus have been infected with the software or documents, and can not protect
against data- driven attacks.
二、网络防火墙技术
是一种用来加强网络访问控制,防 止非法手段外部网络用户进入外部网络的内部网络,通过访问
内部网络资源和保护内部网络运行环境为网 络互连的特殊设备。这是两个或两个以上的封包传输
连接网络,比如按照一定的安全战略实施查验,以决 定是否允许网络之间的通信、监控网络运行。
虽然防火墙是保护网络入侵的一种有效方法,但存在着明显 的不足:通过防火墙不能保护免受外
部攻击其他的手段,不能防止叛逃者从内部威胁和无意用户,但也不 能完全防止禽流感病毒传播
的已经感染上了软体或文件,并不能防止数据驱动的攻击。
3, security encryption technology

Encryption technology for the global e-commerce to provide a guarantee, so
that Internet-based electronic trading system has become possible, thus
improving the symmetric encryption and asymmetric encryption technology is
still the mainstream of the 21st century. Symmetric encryption to the
conventional password-based technology, computing encryption and
decryption operations use the same key. Asymmetric encryption, encryption
key that is different from the decryption key, encryption keys are made public,
anyone can use, only the decryption key to decrypt people know.
三、安全加密技术
加密技术,为全球电子商务提供担保,所以网络电子交易系统已经成为可能 ,从而提高对称加密和
非对称加密技术仍然是主流的二十一号世纪。传统的基于口令的对称加密技术,电 脑操作加密和
解密使用相同的钥匙。不对称密钥加密,是不同于解密钥匙,加密密钥公开,任何人都可以 使用,
只有密钥进行解密人们知道。


4, the network host operating system security and physical security measures
Network firewall as the first line of defense and can not fully protect the internal
network, must be combined with other measures to improve the safety of the
system level. After the firewall is based on the network host operating system
security and physical security measures. In accordance with the level from low
to high, namely, the physical security of the host system, the core operating
system security, system security, application services security and file system
security; At the same time, host security checks and bug fixes, as well as a
backup safety system as a supplementary safety measures. These constitute
the entire network system, the second line of defense, the main part of a
breakthrough to prevent the firewall as well as attacks from within. System
backup is the last line of defense network system, used to attack after the
System Restore. The firewall and host security measures is the overall system
security by auditing, intrusion detection and response processor constitute the
overall safety inspection and response measures. It from the network system
firewall, network host or even directly from the network link layer on the
extraction of network status information, as input to the intrusion detection
subsystem. Intrusion Detection System in accordance with certain rules to
determine whether there is any invasion of the incident, if the invasion
occurred, the emergency treatment measures, and generate a warning
message. Moreover, the system's security audit also can be used as the future
consequences of aggressive behavior and to deal with security policy on the
system to improve sources of information.
四、网络主机操作系统安全及物理安全措施
防火墙作为网络的第一道防线,不能很好地保护内 部网络,必须密切结合其他措施,以提高系统的
安全水平。在防火墙是基于网络主机操作系统安全及物理 安全措施。按照从低到高的水平,即物

理安全的主机系统、核心操 作系统安全、系统安全、应用系统安全、档案系统安全性;同时,主人
的安全检查和修复错误,还有一个 备用的安全系统作为一种辅助安全措施。这些构成整个网络系
统、第二防线的主体,防止一个突破防火墙 以及攻击在里面。系统备份是最后一道防线网络系统,
用来攻击后系统恢复。防火墙与主机安全措施是一 个全面的系统安全审计、入侵检测和响应处理
器构成的整体安全性检验和因应措施。它从网络系统防火墙 ,网络服务器或甚至直接从网络链路
层的网络状态信息的提取,作为神经网络的输入,入侵检测系统。入 侵检测系统在按照一定的规则
来决定是否有任何入侵事件的发生,如果入侵、应急处理措施,并产生一个 警示。此外,系统的安
全审计也可做为未来后果的攻击性行为和处理安全政策体系,改善信息来源。


In short, network security is a comprehensive issue, involving technology,
management, use and many other aspects, including both its own information
system security issues, there are physical and logical technical measures, a
kind of technology can only solve the problem on the one hand, rather than a
panacea. To this end the establishment of a network with Chinese
characteristics, security system, the need for national policies and regulations
to support and joint research and development group. Security and
anti- security like two sides of contradictions, always pick-up, so the security
industry is a future with the development of new technologies and the
continuous development of industry.
简而言之, 网络安全是一个综合性的问题,涉及技术、管理、使用和其他许多方面,包括它自己的
信息系统安全问题 ,还有物理和逻辑的技术措施,一种技术只能解决问题;另一方面,而不是万灵
药。为此建立具有中国特 色的网络安全体系,需要国家政策法规支持和共同研究开发小组。安全
与anti-security矛 盾的两个方面,就像总是拾音器,所以安全产业是未来与新技术的发展和不断
发展的工业。