Network Services

Introduction

Network service provides functionality to the user, e.g. e-mail, WWW, DNS. The service has a common name, e.g the e-mail, but the technical side of it is governed by so-called protocols (in the case of email, it could be IMAP4 or POP3 protocols).

Internet service examples

• DNS: Domain Name System translates the domain names to IP addresses

• E-mail: messages are being transferred using the Simple Mail Transfer Protocol (SMTP). The client mail is submitted by user passes through a msender ail server, from there to mreciever mail server. nce the final server accepts the incoming message, it saves it the relevant mailbox from where they can be downloaded by reciever (governed by POP3 protocol)
• WWW: World Wide Web is a system of interlinked, hypertext documents accessed through the Internet. It is controlled mainly by HTTP protocol

• File sharing: File sharing is a technology that allows any networked computer to copy files located on other computers (domain owners).

• Instant messaging: IM is real-time text transmission with the use of internet technologies. It allows people to communicate with each other in different chat forums. Where all the participants in the chat group can see the posted messages. Chat services such as Skype and MSN Messenger allows users to create private channels. Instant messaging system will also alert users when a person is online

• Grid computng: GC is a computer network in which each computer's resources (processing power, memory) are shared with every other computer in the system. CP provides a huge computing power for demanding tasks (e.g genome sequencing)

• Voice over IP: Voice over Internet Protocol is a method and group of technologies for the delivery of voice communications and multimedia sessions over IP networks, such as the Internet.

• HW sharing: e.g. printers sharing