Networks L4 Client-Server Networks PDF

Client-Server Networks Networks Learning Objectives Understand what constitutes a client-server network Contrast a client-server network with a peer-to-peer network Be able to list advantages and disadvantages of each model Understand what is meant by cloud computing List the main advantages of clo...

Client-Server Networks Networks Learning Objectives Understand what constitutes a client-server network Contrast a client-server network with a peer-to-peer network Be able to list advantages and disadvantages of each model Understand what is meant by cloud computing List the main advantages of cloud computing A client-server network The clients are the computers which people log on to in order to use the network The server is a powerful computer which provides services required by any of the clients Client Query Response Search Data Server A Google server room in Council Bluffs, Iowa Photo: Google/Connie Zhou See more images of Google data centres Advantages of a client-server network Data and applications are held centrally, so: All data can be backed up centrally rather than on each individual computer Anti-virus software can be kept up to date and run by the server Security is better because data is held in one location rather than all over the organisation Users can log in from any computer on the network Disadvantages of a client-server network Expensive to install If the server goes down the whole network is out of action Server can be overloaded and be slow if too many clients are using it Peer-to-Peer (P2P) Networks An alternative to a client-server network There is no central server. Each computer holds its own applications and data Commonly used in homes and small offices Advantages of P2P Networks A printer or a scanner, for example, can be shared Each user can access data on another computer in the network A single router can provide access to the Internet for all users on the network Easier and less expensive to set up than a client-server network Peer-to-peer file sharing File sharing websites use peer-to-peer networking over a Wide Area Network This can encourage illegal sharing of copyright protected material such as music and software Cloud Computing: what is it? Software applications and data are held on the network of computers that make up the “Cloud” Typically accessed using a Web browser such as Chrome or Internet Explorer. Cloud Computing: how do I access it? If you have an email account such as Gmail or Hotmail, you are already using cloud computing! The software and storage for your account is not held on your computer – it’s on the service provider’s cloud Usually, each application will have its own dedicated server Cloud Computing applications Store your data, music and photos on the cloud. E.g. Google Drive, SkyDrive or Dropbox The applications are potentially limitless, from word processing or database software, business applications and online exams, to apps that you run on your smartphone Online applications Advantages of Cloud Computing You can access your data and applications from anywhere at any time You don’t need a powerful computer with a huge hard drive – everything is stored and run on a remote computer Backing up data is no longer crucial – it is done by the service provider Disadvantages of Cloud Computing The idea of handing over important data to another company worries some people Sensitive data could be more vulnerable to hacking While you can usually store a limited amount of data for free, you have to pay to store more than the free allowance