Lecture 7. Networking and telecommunications

Purpose Basic concepts and LAN components Types of networks Architecture of a network. Technologies of connection to the Internet

Vocabulary Computer Network Local area network Metropolitan area network Wide area network Communication hardware Network Topology Switch Hub Router Twisted-pair cable Fiber-optics Coax-Cable компьютерная сеть локальная вычислительная сеть общегородская сеть глобальная сеть коммуникационное оборудование топология сети переключатель хаб маршрутизатор Витая пара Волоконная оптика Коаксиальный кабель

1. Basic concepts and LAN components Computer Network - An interconnection of computers and computing equipment using either wires or radio waves over small or large geographic distances.

The network usually includes four things: 1. Protocol - a set of communication rules to make sure that everyone speaks the same language. 2. Network interface card (NIC) - card that plugs into the back (or side) of your computers and lets them send and receive messages from other computers. 3. Cable - the medium to connect all of the computers together. 4. Hub (switch or router) - hardware to perform traffic control.

A network interface card (NIC) is a circuit board or card that is installed in a computer so that it can be connected to a network. 

Communication hardware A modem is a device or program that enables a computer to transmit data over, for example, telephone or cable lines.

Communication hardware

Physical Transmission Media Coax-Cable plastic outer coating woven or braided metal insulating material copper wire Twisted-pair cable protective coating glass cladding optical fiber core Fiber-optics

2. Types of networks Some of the different networks based on size are: Personal area network, or PAN Local area network, or LAN Metropolitan area network, or MAN Wide area network, or WAN

Types of networks PAN

Wireless Local Area Network This is a LAN which works using wireless network technology such as Wi-Fi.

3. Architecture of a network The architecture of a network is a logical design that determines how the devices in the network communicate. The commonly used architectures for computer networks are:  Client-server architecture  Peer-to-peer architecture  Hybrid architecture

Client-server architecture is a computing model in which the server hosts, delivers and manages most of the resources and services to be consumed by the client.

Peer-to-peer architecture is a decentralized communications model in which each party has the same capabilities and either party can initiate a communication session.

The OSI model OSI ( Open System Interconnect ) describes a framework to subdivide connection problems in networks into almost independent sub-problems

Network Topology Network Topology is an arrangement of nodes, nodes are basically components of network.