1.4 Wired And Wireless

1.4 Wired And Wireless

1. LAN (Local Area Network)

   • is a computer network that spans a relatively small area. Most often, a LAN is confined to a single room, building or group of buildings, however, one LAN can be connected to other LANs over any distance via telephone lines and radio waves.

2. WAN (Wide Area Network)

   • consists of two or more local-area networks (LANs). Computers connected to a wide-area network are often connected through public networks, such as the telephone system. They can also be connected through leased lines or satellites.

3. Client-Server

   • is a distributed application structure that partitions tasks or workloads between the providers of a resource or service, called servers, and service requesters called clients. A server host runs one or more server programs which share their resources with clients.

4. Peer-to-Peer

   • is a distributed application architecture that partitions tasks or workloads between peers. Peers are equally privileged, equipotent participants in the application. They are said to form a peer-to-peer network of nodes.

5. 1.4 WIRED AND WIRELESS

   • QUESTIONS AND ANSWERS
     • What are the two advantages of networking advantages? (2)
       • Site (software) licences are likely to be cheaper than buying several standalone licences. Network users can communicate by email and instant messenger. Security is good - users cannot see other users' files unlike on stand-alone machines.
       • You can socialise around the world and also can connect with other networks share data
     • What are the two disadvantages of networking advantages? (2)
       • Purchasing the network cabling and file servers can be expensive. Managing a large network is complicated, requires training and a network manager usually needs to be employed.
       • If the file server breaks down the files on the file server become inaccessible. Email might still work if it is on a separate server. The computers can still be used but are isolated.
       • Viruses can spread to other computers throughout a computer network. There is a danger of hacking, particularly with wide area networks. Security procedures are needed to prevent such abuse, eg a firewall.
     • What does WAN mean? (1)
       • Wide Area Network
     • What is the definition of 'Bandwidth' ?
       • a range of frequencies within a given band, in particular that used for transmitting a signal.
   • KEY NOTES
     • A client-server relies on a central server
       • Includes high traffic environmement
     • In peer to peer, each device can act as a client & a server and which all files stored on their own computer
       • All computers have equal status
       • Whilst peer to peer has a low traffic environment
       • Installation for peer to peer has to happen locally (one at a time)
     • WAN (Wide Area Network) has a large geographic are whilst LAN (Local Area Network) has a small geographic area
       • It is the biggest network- Internet
       • LAN (Local Area Network) e.g. home, school, in a shop
     • High end powerful services/servers can store all files centrally and you access the files from any computer
       • Print services/file services
     • WAN(Wide Area Network) has an external hardware and infrastructure
     • Client Server
       • Antivirus
       • Firewall
       • Installed and configured from a central location
     • Speed Bandwidth
       • Up to 1000 megabits per second
     • Arpenet
       • First ever network
       • Joined devices together

6. Cabeling Network

   • are networking hardware used to connect one network device to other network devices or to connect two or more computers to share printers, scanners? Electrical connections using twisted pair or coaxial cable are used within a building.

7. Router Protocol

   • specifies how routers communicate with each other, distributing information that enables them to select routes between any two nodes on a computer network. Each router has a prior knowledge only of networks attached to it directly.

8. Network Interface Card (NIC)

   • controls the wired and wireless connections of a computer to exchange information with other computers and the Internet.

9. Sequence Number

   • is a 32-bit internal numerical sequence number assigned to data fragments by Stream Control Transmission Protocol (SCTP). TSNs are independent of other stream sequence level numbers and acknowledged by receiving end points, even during sequencing gaps.

10. Physical Hardware

    • is the collection of physical parts of a computer system. This includes the computer case, monitor, keyboard, and mouse. It also includes all the parts inside the computer case, such as the hard disk drive, motherboard, video card, and many others.

11. Fiber Optic

    • is a high-speed data transmission medium. It contains tiny glass or plastic filaments that carry light beams.The receiving end of a fiber optic transmission translates the light pulses into binary values, which can be read by a computer.

12. Coaxial Cable

    • is a type of shielded and insulated copper cable that is used in computer networks and to deliver cable TV services to end users. Coaxial cable is also known as coax, which is derived from the geometric axis created between a shield and insulator.