无秩序的） enough, the "mayor" (the user) wants to come through right now. Somehow, everyone gets through.
The computer’s operating system (OS
A computer is an electronic（adj.操作，使用） other forms of information.
The modern world of high technology could not have c
Intranets and extranets
One common configuration of a LAN is an intranet. Intranet Web servers differ from public Web servers in that the public must have the proper permissions and passwords to access the
Virtual private network (×××)
A vitual private network (***) is a private network that is constructed within a public network infrastructure such as the global Internet. Using ***, a telecommuter can remotely ac
MANs and SANs
Metropolitan-area networks (MANs)
Wireless bridge technologies that send signals across public areas can also be used to create a MAN. A MAN usually consists of t
Wide-area networks (WANs)
WANs interconnect LANs, which then provide access to computers or file servers in other locations. Because WANs connect user networks over a large geographical area, they make it po
Local-eare networks (LANs)
LANs consist of the following components:
Network interface cards
LANs allow businesses to lo
Protocol suites are collections of protocols that enable network communication between hosts. A protocol is a formal description of a set of rules and conventions that govern a part
Network topology defines the structure of the network. One part of the topology definition is the physical topology, which is the actual layout of the wire or media. The other part
Equipment that connects directly to a network segment is referred to as a device. These devices are broken up into two classifications. The first classification is end-user devices.
The history of computer networking is complex. It has involved many people from all over the world over the past 35 years. Presented here is a simplified view of how the
Data networks developed as a result of business applications that were written for microcomputers.
The microcomputers were not connected so there was
Converting between decimal numbers and 8-bit binary numbers
1、Convert the decimal number 168 to a binary number:
128 is less than 168 so the left most bit in the binary number is a 1. 168 - 128 = 40.
64 is not less than or equal to 40 so the second bit from
Base 2 number system
The number system that computers use to recognize and process data, which is binary, or Base 2.
The binary system uses only two symbols, which are 0
Base 10 number system
Numbering systems consist of symbols and rules for their use.
Base 10 uses the ten symbols 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9. These symbols, can be combine
Bits and bytes
A binary 0 might be represented by 0 volts of electricity.
A binary 1 might be represented by +5 volts of electricity.
Binary presentation of data
Computers work with and store data using electronic switches that are either ON or OFF. Computers can only understand and use data that is in this two-state or binary format. The 1s
Web browser and plug-ins
A Web browser is software that interprets HTML, which is one of the languages used to code Web page content. Some new technologies use other markup languages with more advanced feat
Testing connectivity with ping
Ping is a basic program that verifies a particular IP address exists and can accept requests. The computer acronym ping stands for Packet Internet or Inter-Network Groper. The name
TCP/IP description and configuration
TCP/IP(Transmission Control Protocol/Internet ProtocolTransmission Control Protocol/Internet Protocol） is a set of protocols or rules that have been developed to allow computers to