Network characteristics
According to cover range, the network can be divided into LAN, wan and man, this is the most common computer network classification method. Each network have different features.
(a local area network (LAN)
LAN is the most network application form, is also the subject of a Internet. A computer can construct LAN in just a few or hundreds of Taiwan between. In fact, thanks to the support network game domain has become the basic function of the computer operating system, so in a way, you can also put a computer as a local area network. The Internet is the set of countless LAN.
In a local area network, we are Shared between procedures, such as the document resources, and don’t have to passing back and forth disk, U plate and storage medium; But also through the network to enable computers sharing the same hardware, such as printer, modem, etc.; We can also with through Internet use computer to send and receive fax, convenient and quick and and the economy.
The characteristics of the local area HP CQ40 battery network
The distribution of local area network of small, less investment, simple configuration, it basically has the following features:
The transmission rate high: generally is 1-1000 Mbps, optical fiber high-speed network of up to 100 Mbps, 1000 Mbps;
Support the transmission medium variety;
Communication processing general by nic complete;
Transmission of good quality, low; ber
There are rules of topological structure.
The composition of the local area network:
LAN by server, users generally workstations, nic, transmission medium to four parts.
Server: running a network operating system, provide the hard disk,
File data and printer sharing and so on the service functions, is the core of the network control system. Common NOS mainly NetWare, Unix and Windows series 3 kinds.
NetWare: is the first real network operating system, its popular version has V3.12, V4.11, V5.0, demand for hardware, technology to improve, reliable low, a hold DuoZhong workstations and agreement, is suitable for the local area network operating system, as the document, print server service good performance. Novell NetWare is the product of the company, especially the development of the local area network to network made very great contribution, but not often unfortunately, the products and the company has been close to disappear, because they face opponent is Microsoft and Windows. Unix:-kind of typical multi-user NOS, mainly used in MSI Wind U100 battery super minicomputer, large machine. Support network file system service, provides the data applications, powerful, not easy control, command complex, from AT&T and introduced the remoted SCO.
Unix has DuoGe version and manufacturers, is also the most stable network operating system. But, early bad (known as professional > operation interface make it far from the big wide user groups.
Linux: a source close to the development and free Unix, the two big advantages decided their won’t be optional.
Windows series: a graphic application For distributed the integrity of the platform, the first of all network version comes from Windows3.1 version, is also the Windows For Workgroup later turned into Windows NT. It is easy to install and management, and the integration of a network management tools than India, wide wide prospect. This is at present the most popular system, although there are many shortcomings. The server is divided into a file server, to print the server, database server, in the Internet, and the Web, FTP, such as E-mail server. Network OS can support DuoZhong toward communication protocol, DuoZhong network adapter and workstations the direction of development.
The workstation: can have their own OS, independent work, through the operation work station network software, access Server sharing resources.
Network card: will the workstation type server even to the web, to realize the resource share and mutual communication, data transformation and electrical signals match.
Transmission medium: the common transmission medium have twisted pair, coaxial cable, optical fiber, etc.
Field work mode. Several kinds of nets
A dedicated server structure
Also known as “the workstation/file server” structure, with several microcomputer workstations and one or multiple file server through the communication lines connected workstation access server of files, sharing storage devices.
The file server natural by sharing the disk file for the main purpose. For the average for data transfer have been will be enough, but when database systems and other complex and be increased users with the use of the application system comes, service is already can’t take such tasks, because for the increase of the number of users, with the door for each service programs are increasing, every application is independent running large files, to the user feels very slow, resulting in a client 7 server mode.
Customer intends to server mode which one or several sets of large computer focus on a Shared database management and access, called the server, and other applications will handle work across the network computer, go up do other form of distributed processing system.
C/S model development mainly attributed to the database server. As the database of theory and technology in mature, a large number of data into the computer management. Rely on gradually with the network into technology and information system, form the professional Toshiba PA3450U-1BRS battery database server, the computer for data management way by the file management rise of database management mode.
The database, and file systems, focused on a different definition and access data backup and restore security, concurrent control and transaction management, implement such as choice retrieval and index sort and several library management function, it according to have enough power to do through its deal with the after that part of the customer need data and not the entire file through the network transmits to the client to reduce the transmission of the network, the load. C/S structure is database technology development and common application and bureau domain nets technology development of combining the results.
The network topology structure of equation in with special Server and C/S the same. In the equation, the network structure 1 without dedicated server, each workstation can up client effect might also be the server role.
With the computer processing power and speed to get substantially rise, a common PC has more than the original server processing power, enough to complete the server, so any affairs peer-to-peer network has become the mainstream of a local area network, especially in the daily do male environment.
