Fase De Planeación

Andrés Felipe Quiceno

Alejandro Álvarez

10-4

Institución Educativa Académico

SENA CTA

Cartago (valle)

Octubre 2015

A local area network or LAN (for the abbreviation of Local Area Network) is a computer network covering a small area of a house, an apartment or a building.

The network topology defines the structure of a network. One part of the topology definition is the physical topology, which is the actual layout of the wire or media. The other part is the logical topology, which defines how the hosts access the media to send data.

The term local network includes both hardware needed for the interconnection of different devices and data processing software.

Characteristics:* Technology Broadcast (diffusion) with shared transmission medium.* Specified layout usually installed on purpose.* Transmission capacity ranging from 1 Mbps to 1 Gbps.* Maximum length not exceeding 3 km (One FDDI can reach 200 km)* Use of a private media.* The simplicity of the transmission medium used (coaxial cable, telephone cable and optical fiber).* The ease with which you can make changes to the hardware and software.* Wide range and number of connected devices.* Can be connected to other networks.

ComponentsServer: The server is one or those computers that will share their hardware and software resources with other computers on the network. Its characteristics are computing power, importance of information that stores and connection with resources to share.Workstation: the computers that take the role of leverage or workstations have at their disposal the resources offered by the network and the services provided by servers that can access.

Physical Topologies

Topologies most commonly used are:

A bus topology uses only one backbone cable that is terminated at both ends . All the hosts connect directly to this backbone. Its operation is simple and very easy to install, but is very sensitive to traffic problems and a failure or a break in the cable stops all transmissions.

A star topology connects all nodes with a hub. The hub connects directly to the nodes, sending node information source, constituting a point to point network. If a node fails, the network continues to operate, but if the central node fails, the transmissions are interrupted

An extended star topology links individual stars together by connecting hubs (hubs) or switches. This topology can extend the scope and coverage of the network.

A hierarchical topology is similar to an extended star. But instead of linking the hubs or switches together, the system is connected to a computer that controls the traffic on the topology.

The tree topology has several terminals connected in a network that branches from a server base. A failure or breakage in the cable interrupted transmissions.

The mixed topology is one in which a mixture of any of the other topologies applies: bus, star or ring. Mainly we can find two mixed topologies: Star- bus and star - ring. The most used cables are the twisted pair, coaxial cable and fiber optics.

Logical topologies

The logical topology of a network is how the hosts communicate across the medium. The two most common types of logical topologies are broadcast and token passing.

Broadcast topology simply means that each host sends its data to all other hosts on the network medium. There is no order that the stations must follow to use the network. It is first come, Ethernet's how it works.Topology token passing controls network access by passing an electronic token to each host sequentially. When a host receives the token, that host can send data over the network. If the host has no data to send, it passes the token to the next host and the process repeats. Two examples of networks that use token passing are Token Ring interface and Fiber Distributed Data (FDDI). Arc net is a variation of Token Ring and FDDI. Arc net is token passing on a bus topology.