Local area networks

Local area networks

Local area networks or LAN (Local Area Network) are private networks that enable connection with subsequent exchange of information between multiple devices in a limited geographical.

The networks generally have different names according to the geographical area covered:

. Networks WAN (Wide Area Network)

. Networking MAN (Metropolitan Area Network)

. Networking LAN (Local Area Network)

. Networks WLAN (Wireless Local Area Network)

Networks to:

. Access to databases of nearby areas;

. Sharing programs between expensive equipment of the same environment;

. Provide internal users of a given area services of the Internet.

The architecture of a network can be a star or ring.

A structure may have different frame.

. The frame of the plan, which is developing the distribution horizontal facing up users.

. The frame of a building from which develops the backbone or vertical distribution of building and connecting the various permutations of the plan of that 'building.

The components that make up a typical LAN are:

. Stations: all stations are defined as the devices that are source and / or destination of the data exchanged in the network can handle the functions of communication and control network.

. The devices: are the devices connected to a station, such as printers, disks, plotters and so on. These devices are not considered because of the stations are not able to fully manage the network functions. Devices of each station must be accessible by the stations of the network and all users in order to achieve a sharing of resources.

. The communication channel is also known as system wiring. It includes the transmission medium consists of a set of cables that defines the interconnection between the stations, peripheral devices and all devices that need to send or receive signals. In cases where stations are far apart you need to put repeaters rigenerino signal that the signal on a regular route in order to have a program as good as possible.

. The switch is a device able to route data packets in a point to point. This is because the switch is to designate a table of all addresses of the network adapters connected and when a package arrives knows who the recipient and sends it only to him.

When one comes to the switch is analyzed, and reading the header of the frame you can know who has sent the data, and then sent to the recipient. In this way the data is running a route point to point (from point to point), saving a considerable amount of bandwidth.

. The router is a 'routing' of information to sort the information traveling in the form of packages, which is used to manage access to the Internet.

. The server corresponds to the station providing the resources (applications and services) which acquire the computers connected to the network.

. The clients are the workstations that require services to servers.

To install a local area network must know the type of transmission medium and the technique of transmission that we use.

. type of transmission medium: the physical connection may be generally of three types, namely the telephone shielded twisted pair, coaxial cable and fiber optics;

. transmission technique are of two types, base-band and broadband, employees of the means of transmission;

Once the physical connection between all parties concerned, we proceed to the configuration of your network card. For communication between the PC in the network must install a special protocol called TCP / IP which assigns to every client:

. An IP address;

. A domain name;

. A subnet mask;

. A gateway address;

. A DNS address.

IP Address: Every computer connected to the network must be labeled with an address called IP address, consisting of four numerical dot, like this: 192.168.xy, which uniquely identifies a resource on the network (a PC, a printer, a router etc..).

The domain name represents the name of the PC in the network identified in a particular domain assigned by the provider.

Subnet mask: used to understand what 'is the network of a PC.

Gateway address is a numeric address four points representing the PC that connects your network to the Internet. Represents the address of the machine that connects to the internet provider.

Address DNS (Domain Name System) is a service used to resolve host names into IP addresses and vice versa. The service is realized through a distributed database consisting of the DNS server.