Exercise 3 – Networked Computing

A small team of students providing a consultancy service to a client such as the owner of an Internet café wishing to network the computers.

 List the advantages of networked computing relative to standalone computing

Following are the advantages of networked computing relative to standalone computing:-

1. Fewer Peripherals Needed -many devices can be connected on a network. Each computer on the network does not need to have its own printer, scanner, or backup device. Multiple printers can be set up in a central location and shared among the network users. All network users send print jobs to a central print server that manages the print requests. The print server can distribute print jobs over multiple printers, or queue jobs that require a specific printer.

2. Increased Communication Capabilities-Networks provide several different collaboration tools that can be used to communicate between network users. Online collaboration tools include e-mail, forums and chats, voice and video, and instant messaging. With these tools, users can communicate with friends, family, and colleagues.

3. Avoid File Duplication and Corruption-A server manages network resources. Servers store data and share it with users on a network. Confidential or sensitive data can be protected and shared with the users who have permission to access that data. Document tracking software can be used to prevent users from overwriting files, or changing files that others are accessing at the same time.

4. Lower Cost Licensing- Application licensing can be expensive for individual computers. Many software vendors offer site licenses for networks, which can dramatically reduce the cost of software. The site license allows a group of people or an entire organization to use the application for a single fee.

5. Centralized Administration -Centralized administration reduces the number of people needed to manage the devices and data on the network, reducing time and cost to the company. Individual network users do not need to manage their own data and devices. One administrator can control the data, devices, and permissions of users on the network. Backing up data is easier because the data is stored in a central location. 6. Conserve Resources -Data processing can be distributed across many computers to prevent one computer from becoming overloaded with processing tasks.  Distinguish between client/server and peer-to-peer networks

There are essentially two types of network architectures—client-server and peer-to-peer.

A client-server model can be defined as a centralized environment, where all users, objects, resources, and so on are administered in a centralized location and can, if configured, use any network resources on any workstation on the domain. A Peer-to-peer model can be defined as a decentralized environment, where the user must be assigned permissions on each workstation in order to access any available resources.

 List elements common to all client/server networks

There are three elements common to all client/server networks which are as follows:-

1. Clients: The devices that request information from servers 2. Medium: The devices that allow clients to communication with servers and vice versa 3. Server(s): Devices that contain and retain information/data and fulfill requests of clients.

 Describe several specific uses for a network

1. File sharing –Network file sharing between computers gives you more flexibity than using floppy drives or Zip drives. Not only can you share photos, music files, and documents, you can also use a home network to save copies of all of your important data on a different computer. Backups are one of the most critical yet overlooked tasks in home networking.

2. Printer / peripheral sharing –Once a home network is in place, it's easy to then set up all of the computers to share a single printer. No longer will you need to bounce from one system or another just to print out an email message. Other computer peripherals can be shared similarly such as network scanners, Web cams, and CD burners.

3. Internet connection sharing - Using a home network, multiple family members can access the Internet simultaneously without having to pay an ISP for multiple accounts. You will notice the Internet connection slows down when several people share it, but broadband Internet can handle the extra load with little trouble. Sharing dial-up Internet connections works, too. Painfully slow sometimes, you will still appreciate having shared dial-up on those occasions you really need it.

4. Multi-player games - Many popular home computer games support LAN mode where friends and family can play together, if they have their computers networked.

5. Internet telephone service - So-called Voice over IP services allow you to make and receive phone calls through your home network across the Internet, saving you money.  What is a network

The network allows computers to communicate with each other and share resources and information.

 What is a Local Area Network (LAN)

A local area network (LAN) is a computer network covering a small physical area, like a home, office, or small group of buildings, such as a school, or an airport. Current wired LANs are most likely to be based on Ethernet technology, although new standards like ITU-T G.hn also provide a way to create a wired LAN using existing home wires (coaxial cables, phone lines and power lines).

 What is a Wide Area Network (WAN)

A wide area network (WAN) is a computer network that covers a broad area (i.e. any network whose communications links cross metropolitan, regional, or national boundaries ). Less formally, a WAN is a network that uses routers and public communications links Contrast with personal area networks (PANs), local area networks (LANs), campus area networks (CANs), or metropolitan area networks (MANs), which are usually limited to a room, building, campus or specific metropolitan area (e.g., a city) respectively. The largest and most well-known example of a WAN is the Internet. A WAN is a data communications network that covers a relatively broad geographic area (i.e. one city to another and one country to another country) and that often uses transmission facilities provided by common carriers, such as telephone companies. WAN technologies generally function at the lower three layers of the OSI reference model, the physical layer, the data link layer, and the network layer.  Sketch a Basic Ethernet LAN

Examples of Ethernet LAN Diagram  Sketch for the networks

With Edraw Network Diagram you can diagram a network or create a computer network diagram using specialized libraries of network symbols such as computers, hubs, routers, smart connectors etc. that simulate network design topologies and devices, network architectures.  Sketch a Peer-to-peer network

A peer-to-peer distributed network architecture is composed of participants that make a portion of their resources (such as processing power, disk storage, and network bandwidth) available directly to their peers without intermediary network hosts or servers. Peers are both suppliers and consumers of resources, in contrast to the traditional client-server model where only servers supply, and clients consume. .

 Sketch a Client/server network

There are various ways to arrange computers on a network. One of these arrangements is called the 'client \ server' model. In this arrangement, a single computer called a 'server' is given the duty to provide a particular service on behalf of one or more 'client' computers. The clients make requests to the server and the server responds to the requests.

There are many kinds of server that include File server - stores, handles and serves files to clients Print server - stores, handles and organizes printing jobs for its clients FTP server - provides a means to move large amounts of data Video server - stores and distributes video files Backup server - sits on the network taking periodic backups of clients. ………………………………………………………………………………………………….