Networking Relationships

What is a computer network?

What is a Computer Network?

– a network is: • group of two or more nodes

• connected together by transmission media

• for the purpose of sharing resources

Network Elements

– Node• a node is any hardware device that is directly

connected to a network

• Examples include:– Assorted types of computer systems

– Printers and plotters

– Scanners

– Communication hardware (modems, etc.)

– Hard Disk Drives

Network Elements

– Transmission Media• the transmission media consists of the physical

connections, that facilitate the transmission of signals, between nodes on a network

– Telephone lines

– Twisted Pair cable

– Coaxial Cable

– Fiber-optic Cable

– Microwave Transmission

– Satellite Transmission

Network Elements

– Resource• a resource is a hardware, software, or data source

• Examples include:– Storage space on Secondary Storage

– Ability to send a email from an iPhone

– Processing power of high performance CPU

– Outputting to high quality printer

– Application executed from HD of remote system

– Transfer of data files from node to node

– Web Pages requested and received

Types of Nodes– A typical network includes several nodes; some nodes

act as server, some as client, and some as both server and client

– Server• a server is a node that makes its resources available to and for

use by other network nodes; therefore, a server shares its resources across the network

– Client• a client is a node that requests and uses resources on a network

which are made available and shared by a server on the network

How are Resources Shared?

– Resources are shared across networks through network services

– Service• a service is a communication scheme or standard

supplying some public demand for shared resources on a network; scheme consists of user interaction characteristics and the protocol for transmitting signal.

Network Services

– Lets look at a specific network, the Internet– Internet

• the Internet is a global public network facilitating all sorts of services; the Internet is the largest world-wide network

• Like in smaller networks, resources are shared over the Internet using services

Network Services

– Some of the services facilitated by the Internet are:• E-mail

– the email service is a network service that facilitates exchange of messages

• World Wide Web– the world wide web service (WWW) is a network service

facilitating the transfer and display of hypertext document files

• File Transfer Protocol– the file transfer protocol service (FTP) is a network service that

allows for relatively fast transfer of whole files