Network is a group of computers, printers, and other devices that are connected to a cable. Sharing data and resources. Information is passed over cables, enabling network users to exchange documents and data, print on the same printers, and generally share any hardware or software that is connected to the network. Each computer, printer, or peripheral device connected to another network is called a node. The networks can have ten, thousands, or even millions of nodes.
The two most popular types of power cables are twisted pair (also called 10BaseT) and thin coaxial (also known as 10Base2). 10BaseT cabling looks like a conventional phone cord, except that it has four wires instead of 4. The thin coaxial look is a copper coaxial wiring that is often used to connect the VCR and the TV.
A network computer is connected to network cabling with a network card (called "NIC", "nick", or AC adapter). Some network cards are built into the computer: the computer is open and a network card is connected directly to the computer's internal slots. 286, 386 and many 486 computers have 16 bit slots, so 16 bit NIC is required. Faster computers, such as high-speed 486 and Pentium, often have 32-bit or PCI slots. These PCs require 32-bit NICs to reach the fastest network speed for speed-critical applications, such as desktop video, multimedia, publishing, and databases. And if you use a computer for the Fast Ethernet network, you will need a network adapter that supports the 100 Mbps data rate.
The last piece of the network puzzle is called a hub. The hub is a box that is used to collect PC sets in a central location with 10BaseT cabling. If a small group is connected to a network, you can access a hub, a 10BaseT cable, and a handful of network adapters. Larger networks often use a thin, co-axial "backbone" containing a series of 10BaseT nodes. Each hub, on the other hand, can connect 10BaseT cabling to a useful computer that allows you to create ten, hundreds or thousands of nodes.
As with network cards, hubs are available both in standard (10 Mbps) and Fast Ethernet (100 Mbps) versions.
Network is a collection of independent computers that communicate with each other through a shared network. Local networks are networks that typically relate to a geographic area, such as a building or university campus. LANs can be small and connect only to three computers, but often connect computers used by thousands of computers. The development of standard network protocols and media has resulted in the worldwide spread of LANs through business and education organizations.
WANs (Wide Networks)
Often a network is located in more physical locations. Wide networking combines several geographically separate networks. This is achieved by using different LANs with services like, for example, Dedicated leased lines, dial lines (synchronous and asynchronous), satellite connections and data packet service providers. Wide networking is as easy as a modem and a remote access server for employees who can count or even become complicated by using globally-linked branch offices through various management protocols and filters, minimizing long distance sending costs.
The Internet is a system of affiliated networks that are in force throughout the world and facilitate data transfer services, such as remote logging, file transfer, electronic mail, the world wide web and newsgroups.
With the meteoric rise in demand for connectivity, the Internet has become a communications highway for millions of users. The internet was initially confined to military and university institutions, but is now a full channel of information and trade. Web sites now provide personal, educational, political and economic resources in every corner of the planet.
With the advancement in web browser-based software, many private organizations implement intranets. The intranet is a private network that uses web-based tools, but is accessible only within that organization. For larger organizations, the intranet provides easy access to corporate information for employees.
Ethernet is the most popular physical layer of LAN technology used today. Other LAN types include Token Ring, Fast Ethernet, Fiber Distributed Data Interface (FDDI), Asynchronous Transfer Mode (ATM), and LocalTalk. Ethernet is popular because it provides a good balance between speed, cost, and ease of installation. These benefits, broad acceptance of the computer market and popular network protocols, Ethernet is the ideal networking technology for Internet users. According to IEEE 802.3, the IEEE standard defines the Ethernet standard. This standard specifies the rules for configuring the Ethernet network and determines how the elements of the Ethernet networks interact. By complying with the IEEE standard, networking devices and network protocols can communicate effectively.
Network protocols are standards that allow computer communication. The protocol determines how computers identify each other on the network, the form that the data needs to pass and how to process this information once it reaches its final destination. The protocols also define procedures for managing lost or damaged data transmissions or "packets". TCP / IP (UNIX, Windows NT, Windows 95 and other platforms), IPX (Novell NetWare), DECnet (Digital Equipment Corp. for computers), AppleTalk (Macintosh computers), NetBIOS / NetBEUI and Windows NT networks) main types.
Although each network protocol is different, each one has the same physical wiring. This common way of accessing a physical network allows multiple protocols to stand in peace on the network media and allow the network builder to use shared hardware for different protocols. This concept is known as "protocol independence", meaning that devices compatible with physical and data link layers allow the user to run different protocols across the same medium.
The network topology is a geometric arrangement of nodes and wiring harnesses in a LAN and is used in two general configurations: bus and star. These two topologies determine how junctions are interconnected. A node is an active device that connects to a network, such as a computer or a printer. The node can be a network device, such as a hub, switch, or router. The bus topology consists of junctions that are connected in a row and each node is connected to a long cable or bus. Many nodes can access the bus and begin communication with other nodes in the particular cable segment. Any section of the cable usually makes the entire segment inoperative until the break is improved. Examples of bus topology: 10BASE2 and 10BASE5.
10BASE-T Ethernet and Fast Ethernet use a star topology in which access is controlled by a central computer. Usually, a computer is located at one end of the segment and the other end ends in a central location with a hub. Because UTP is often operated with the telephone wiring, this central location can be a telephone box or other area where the UTP segment should be connected to a spine. The primary advantage of this type of network is reliability, since if one of the "point" segments breaks down, only the two nodes of the link are affected. Other network users in the network will continue to operate as if this segment did not exist.
Peer-to-Peer Network allows two or more computers to pool their resources. Some resources, such as disk drives, CD-ROM drives, and printers, are transformed into shared, collective resources that are accessible from any PC.
Unlike client-to-server networks where network information is stored on a centralized file server computer and there are ten, hundreds or thousands of client computers available, data stored on interconnected networks is decently decentralized. As peer-to-peer PCs have their own hard disk drives available for each computer, each PC client (information requester) and server (information provider). A peer-to-peer network can be built up with 10BaseT cabling, either a hub or a thin coaxial spine. 10BaseT can reach a minimum of 16 or fewer workgroups that do not travel long distances or workgroups with one or more of their portable computers from time to time disconnected from the network.
After you install the network hardware, you must install a parallel network software package on each computer. Such a package allows users to pass data from a computer, hard drives, and other devices when requested by users. Included in popular peer-to-peer NOS software
Most NOSs allow each peer-to-peer user to determine which resource is available to other users. Special hard drives, libraries, or files, printers, and other resources can be connected or disconnected from the network through software. When a user's disk is set to be "shared", it usually appears as a new drive for other users. In other words, if user A contains a drive A and C on his computer and user B configures his own C drive, user A suddenly drives A, C and D (The drive of the user is actually the user's B & C drive). Libraries work in a similar way. If drives A and C and user B configure "C: WINDOWS" and "C: DOS" directories, user A suddenly drives A, C, D and E
(A & s D is user C: WINDOWS, and E is user B: C: DOS). Did you get all this?
Because drives can be easily shared between peer-to-peer PCs, applications need to be installed on only one computer – not two or three. For example, if users have a copy of Microsoft Word, they can be installed on the user's computer – and can continue to use user B.
Peer-to-peer over client server NOS benefits are:
· No network administrator required
· Quick and inexpensive network setup and maintenance
· All computers can back up data computers for security reasons. The cheapest networking, the peer-to-peer network, is perfectly suited for home and office use.
Client Server Networks
In a client-server environment such as Windows NT or Novell NetWare, files are stored on a centralized high-speed file server that is available to client computers. Network access speeds are typically faster than peer-to-peer networks, which is reasonable because the architecture supports a large number of clients. Almost all network services, such as printing and e-mail, run through the file server, allowing network tasks to be tracked. Ineffective network segments can be reworked to make it faster and users can closely monitor activities. Public data and applications are stored on the file server where they run on client computers. Sites that simplify software upgrades – Network administrators can easily update applications stored on a file server rather than physical updates to individual client computers.
In the following client-server diagram, client computers are separate and the file server is considered subordinate. Customers have primary applications and files stored in common locations. File servers are often set up so that all users have access to their own "directory" on the network as well as a number of "public" libraries where applications are stored. If you want the following two clients to communicate with each other, you have to go through the file server. You send a message sent from one client to the file server first, and then sends it to the destination server. For ten or more client computers, the file server is the only way to handle complex, simultaneous operations that are required by large networks.
The computer network is a very important and critical part of Informatics. Millions of computers are interconnected to create the Internet. Networking plays an important role in all small and medium-sized organizations, banks, multinational corporations, stock exchanges, airports, hospitals, police, post offices, colleges, universities and even at home. plays an important role wherever computers are used. This article will be interesting for students, network specialists and people interested in computer networks