1.4 Wired and Wireless networks

1.4 Wired and Wireless networks

1. Networking

   • is a generic term in computing which refers to computers or nodes working together over a network. It may also mean: Cloud computing, a kind of Internet-based computing that provides shared processing resources and data to devices on demand. Distributed computing.

2. LAN

   • A local-area network (LAN) 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.
   • Small distance / Geographical Area. // Connected by own Hardware

3. WAN

   • Wireless Access Network
     • A computer network that spans a relatively large geographical area. Typically, a WAN 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.

4. Client Server

   • The client–server model 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.

5. Modem

   • modulator-demodulator
     • A demodulator is a circuit that is used in amplitude modulation and frequency modulation receivers in order to separate the information that was modulated onto the carrier from the carrier itself.
   • A modem is a device or program that enables a computer to transmit data over, for example, telephone or cable lines. Computer information is stored digitally, whereas information transmitted over telephone lines is transmitted in the form of analog waves.

6. Router

   • A router is a networking device that forwards data packets between computer networks.
   • Switch
     • A network switch (also called switching hub, bridging hub, officially MAC bridge) is a computer networking device that connects devices together on a computer network by using packet switching to receive, process, and forward data to the destination device.
   • Directs packets/data to destination // directs packets/data in a network  Receives packets/data from the network/Internet  Forwards packets/data to other computers on the network/Internet  Connects (different) networks together // e.g. joins home network to Internet  Has (public) IP address for LAN  Designates (private) IP addresses to network nodes

7. Packet

   • This is a small amount of computer data sent over a network. Any time you receive data from the Internet, it comes to your computer in the form of many little packets. Each packet contains the address of its origin and destination, and information that connects it to the related packets being sent.
   • holds 4 pieces of information
     • IP address from the sever
       • Life Span
     • IP address from the recipient
     • Sequence Number

8. NIC

   • Network
   • circuit board or card that is installed in a computer so that it can be connected to a network. A network interface card provides the computer with a dedicated, full-time connection to a network.

9. Transition Media

   • physical system used to carry a communication signal from one system to another. Examples of transmission media include twisted-pair cable, coaxial cable, and fiber optic cable.
     • Ethernet
       • Ethernet is the most widely installed local area network (LAN) technology. Ethernet is a link layer protocol in the TCP/IP stack, describing how networked devices can format data for transmission to other network devices on the same network segment, and how to put that data out on the network connection.
     • Fiber Optic
       • consisting of or using thin flexible fibres with a glass core through which light signals can be sent with very little loss of strength.
     • Coaxial Cable
       • a transmission line that consists of a tube of electrically conducting material surrounding a central conductor held in place by insulators and that is used to transmit telegraph, telephone, television, and Internet signals — called also coax cable.

10. Network Performance

    • Measures of computer network performance—sometimes called internet speed— are commonly stated in units of bits per second (bps). This quantity can represent either an actual data rate or a theoretical limit to available network bandwidth.

11. DNS

    • A domain name is an identification string that defines a realm of administrative autonomy, authority or control within the Internet. Domain names are formed by the rules and procedures of the Domain Name System

12. VPN

    • A virtual private network (VPN) is a network that is constructed using public wires — usually the Internet — to connect remote users or regional offices to a company's private, internal network.