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Networks:

A group of two or more computer systems linked together. There are many types of computer networks, including:

•local-area networks (LANs) : The computers are geographically close together (that is in the same building). (# relevant for Ecolog-Net)

•wide-area networks (WANs) : The computers are farther apart and are connected by telephone lines or radio waves.

•campus-area networks (CANs): The computers are within a limited geographic area, such as a campus or military base.

•metropolitan-area networks (MANs): A data network designed for a town or city.

•home-area networks (HANs): A network contained within a user's home that connects a person's digital devices.

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Network topology

Topology/structure Advantages Disadvantages

Bus structure -easy to install

-simply expandable

-short cable lengths

-net expansion limits

-by cable interrupt the net precipitates

-complicated access methods

Ring structure -large net expansion -complex error tracing

-high wiring expenditure

-when disturbances net failure

Star structure -simple cross-linking

-simple extension

-high reliability

-high wiring expenditure

-net failure in case of failure or overloading of the hubs

(# relevant for Ecolog-Net)

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LAN – local area network

Simple network:

A simple network consists of at least two computers, which are connected by a direct connection (crossover cable) or with a Hub or Switch.

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LAN – local area network

Hub:

A common connection point for devices in a network. Hubs are commonly used to connect segments of a LAN. A hub contains multiple ports. When a packet arrives at one port, it is copied to the other ports so that all segments of the LAN can see all packets.

Switch:

In networks, a device that filters and forwards packets between LAN segments.

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LAN – local area network

Network with Internet entrance and print server

Router: A device that forwards data packets along networks.A router is connected to at least two networks, commonly two LANs or WANs or a LAN and its ISP’s network (Internet Service Provider).Routers are located at gateways, the places where two or more networks connect.

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LAN – local area network

Radio network - Wireless LAN - WLAN

Instead of cable-based connections;

A simple Wireless LAN is a local network with an ACCESS POINT for WLAN adapter (network interface cards with antenna), which is attached to the computer or inserted.

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LAN – local area network

Access point:AP Short for Access Point, a hardware device or a computer's software that acts as a communication hub for users of a wireless device to connect to a wired LAN. APs are important for providing heightened wireless security and for extending the physical range of service a wireless user has access to.

Network interface card:Often abbreviated as NIC, an expansion board you insert into a computer so the computer can be connected to a network. Most NICs are designed for a particular type of network, protocol, and media, although some can serve multiple networks.