Computer Networks Ing. Vladimír Horák Review •Computer architecture – the logical structure that a computer is made up of •Hardware – all physical components of a computer •Software – all computer programs and applications •Peopleware – the human factor in technology •Orgware – rules and regulations related to the use of technology Review •Computer components – computer case, motherboard, CPU, RAM, drive, graphics card, power supply •Input devices – devices used to give the computer instructions •Output devices – devices used by the computer to provide feedback • • • Today's lecture • Computer networks • Classification of computer networks • Network devices Computer Network • A “system” created by interconnecting computers • • It consists of: • Stations (computers) • Network hardware (network cards, cables, ...) • Network software (programs for working on a network) • • Computer Network • Depending on the role a computer performs in the network, computers are divided into: • Servers • Workstations (Workstation) • • Servers • A computer that provides certain services to others (file, application, mail, ...) • Acts as a control station • There can be an “unlimited” number of servers on the network • • • • What Is A Server? Everything You Need To Know Workstation • A computer used by a user • Uses services provided by a server • Generally a more powerful device than a standard PC • • Classification of Computer Networks • Based on scope • Based on the relationship between nodes • Based on topology • • Classification by Scope • PAN - Personal Area Network, personal network (bluetooth) • LAN - Local Area Network, local network (Wi-Fi) • MAN - Metropolitan Area Network, metropolitan networks • WAN - Wide Area Network – wide-area sítě • • Classification by Node Relationship • Peer-to-Peer •“equal to equal” • A PC connects to a printer and shares it locally with others •Client – Server • One computer offers its services to others • SAN – Storage Area Network • Storage network • Specialized for transferring large amounts of data • • Classification by Topology • Physical •Based on the actual interconnection of devices in the network • Ring, star, ... • • Logical • Based on the communication of individual elements • Bus, ring, ... • Network Devices • Enable connections • Extend the network • Modify its properties • Network Card • Facilitates communication between the computer and the cable • Converts data from a form understood by the computer so that it can be transmitted over the medium • Each network card has its own unique MAC address • Repeater • Used for better signal coverage • Receives the signal, amplifies it, and sends it on • It helps extend the signal into previously inaccessible areas • HUB (network hub) • Used to branch the signal • It can both amplify and modify the signal • Bridge • A device that connects networks using different standards • It can be found, for example, in smart-home devices • Router • A device used to distribute the connection • From home use, we know Wi-Fi routers – “boxes” that create a Wi-Fi network and allow individual devices to connect to the internet • Any questions? Final assignment • We have been talking about networks all this time today. Networks allow us to do many positive things, but there are also negatives associated with them. • • Write down at least 10 different types of threats that can attack us over the network. • Thank you for your attention