Ways To Build Local Networks
Computer network – a complex set of interrelated and coordinated functioning of software and hardware components.
Computer network model can provide a multilayer consisting of layers:
- communications equipment;
- operating systems;
- network applications.
The foundation of any network are PCs that are connected to the network using a network card. All computers local networks can be divided into two classes: servers and workstations.
Network adapter – a special device that is designed for interfacing with a local computer network and to arrange a bi-directional communication network. The network card is inserted into a free slot on the motherboard and is equipped with its own processor and memory, and to connect to the network has a connector RJ-45. The most common type of card PCI, which are inserted into the PCI expansion slot on the motherboard. Depending on the technology used Ethernet, Fast Ethernet or Gigabit Ethernet network card and data transmission rate in the network may be 10, 100 or 1000 megabits / sec.
As a separate cable connects PCs and communications equipment used in local area networks:
- Twisted Pair – transmission line connection which consists of two wires twisted together with a certain pitch in order to reduce the effects of electromagnetic fields.
- Coaxial cable – cable, which consists of a central conductor and the second conductor insulator located on top of the insulator.
- Optical cable – a cable in which the information carrier is the light beam propagating through the optical fiber.
Furthermore, as a transmission medium in a wireless local area network using radio waves in the microwave range.
For communications equipment LANs include transceivers, repeaters, hubs, bridges, switches, routers, and gateways.
Part of the equipment (transceivers or transceivers, repeaters and hubs or repeaters or hubs) is used to connect several computers to the desired network configuration. PC connected to a hub to form a local network segment, i.e. Hubs are a means of structuring the physical network as well as breaking the network into segments that make it easy to connect to the network of a large number of PCs.
Another piece of equipment (bridges, switches) are used for logical structuring of the network. Since LANs are broadcast (Ethernet and Token Ring), then with an increase in the number of computers in a network built on the basis of hubs, increased latency access to computer networks and the emergence of conflicts. Therefore, in networks built on hubs or switches installed bridges between every three or four hubs, ie perform a logical structuring of the network in order to avoid collisions.
The third piece of equipment designed to combine multiple local area networks into a single network routers (routers), Gateways (gateways). This piece of equipment can be attributed, and bridges (bridges), and switches (switches).
- Repeaters – a device for recovery and amplification of signals in a network, serving to increase its length.
- Transceiver – a device for receiving packets from the network controller workstations and transfer them to the network. Transceivers (converters) can convert electrical signals into other signals (optical or radio) to use other transmission media.
- Hub – multiple-access device that combines one point separate physical cable lengths, form a common data transmission medium or network segments, ie Hubs are used to create segments and are a means of structuring the physical network.
- Bridges – a software – hardware devices that provide a combination of several LANs together. The bridges are intended for structuring the logical network connections or substantially identical networks having certain physical differences.
- Switche– software – hardware devices are fast analogue bridges that share a common environment data into logical segments. Logical segment formed by combining multiple physical segments via one or more hubs. Each logical segment is connected to a single port on the switch. When you receive data from the computer – send to any of the ports of the switch will transfer the data, but not on all ports in the Hub, but only to the port that is connected to a segment containing computer – the data receiver.
- Router – These devices provide data path selection between multiple networks having different architectures or protocols. They provide a sophisticated level of service as they can carry out “intelligent” functions: selection of the best route for the transmission of a message addressed to a different network; protection data; buffering data transferred; various protocol conversion. Routers are used only for communication homogeneous networks.
- Gateway) – device (computer), serving to consolidate disparate networks with different communication protocols. The gateways perform protocol conversion to the network, in particular the conversion of messages from one format to another.
The efficiency of the LAN is determined by the parameters defined for the network. Network configuration is based on existing technology and international expertise, as well as internationally accepted standards of building LAN and determined the requirements for it, as well as the financial capacity of organizations.
Based on the existing conditions and requirements in each case selected network topology, cabling, communications equipment, protocols and data transmission techniques, methods of interaction devices, network operating system