WEBMASTER 3224 PHYSICAL VS LOGICAL COMPONENTS OF THE INTERNET AND NETWORKS

THE INTERNET The Internet is a worldwide system of computer networks A Network of networks in which users at one computer can get information from another computer.

THE INTERNET What most people think of when referring to the Internet is the World Wide Web (WWW) The collection of web pages created with HTML coding (HTML5) that you view in a browser. Remember from pervious classes; the term WWW is not the same as the Internet.

THE LOGICAL COMPONENTS OF THE INTERNET The Logical Components of the Internet include a collection of data systems. The WWW is actually only one of these data systems providing the services that make up the Internet. Other data systems include , chat, Newsgroups, Telnet and Videoconferencing.

THE PHYSICAL COMPONENTS OF THE INTERNET The physical components of the internet are the actual devices and hardware that allow the logical components to function This is what makes up the infrastructure of the Internet. These physical components include but not limited to; servers, personal computers, modems, routers, cables, printers, etc…

HOW LOGICAL AND PHYSICAL COMPONENTS WORK TOGETHER Some major services available on the Internet require certain software programs and hardware to be installed along with Internet access, before one can use it. For example “Chat” Session (Logical Component)

CHAT SESSION The “Chat” session will use both audio and video capability It would require a computer to connected to the Internet Instant messaging software A web cam A microphone, and Speakers A Network is required if you are trying to access the Internet from a school or business. (All Physical Components)

THE NETWORK In order to access the Internet from the school; a Network needs to be established. The Network is also made up both Logical and Physical Components Logical Topology shows how data flows within a network, regardless of its physical design. Physical topology is the placement of the various components of a network, including device location and cable installation

PHYSICAL TOPOLOGY This is the networking of the devices topology It refers to the layout of connected devices. Network topologies are categorized into the multiple basic types, three common ones are; 1.bus 2.ring 3.star

BUS TOPOLOGY NETWORK Bus Topology Network use a common device to connect all the devices. This would include a single cable called an Ethernet cable. The cable functions as a shared communication medium that the devices attach into with an interface connector. A device such as a personal computer wanting to communicate with another personal computer on the network sends a broadcast message into the wire (ETHERNET) that all other devices see, but only the intended recipient actually accepts and processes the message.

BUS TOPOLOGY NETWORK The BUS topology is easy to install Don't require much cabling BUS Topology Networks work best with a limited number of devices.

PROBLEMS WITH THE BUS TOPOLOGY NETWORK If more than a few dozen computers are added to a network bus, performance problems will likely result. In addition, if the Ethernet cable fails, the entire network effectively becomes unusable.

RING TOPOLOGY NETWORK In a ring network, every device has exactly two neighbors for communication purposes. All messages travel through a ring in the same direction (either "clockwise" or "counterclockwise").

A failure in any cable or device breaks the loop and can take down the entire network. To implement a ring network, one typically uses FDDI, Sonet, or Token Ring technology.

STAR TOPOLOGY NETWORK A STAR Topology Network has a central connection point called a “HUB NODE” This may be known as a network hub, switch or router. Devices such as personal computers, or printers connect to the HUB with unshielded Twisted Pair “UTP” Ethernet cable.

The Star Topology Network requires more cable compared to the BUS Topology Network. Benefit to the STAR Topology Network is a failure in any star network cable will only take down one computer's network access and not the entire LAN. If the hub fails, however, the entire network also fails.

ETHERNET They also tend to use certain connectivity technologies, primarily Ethernet Ethernet is the transmission of data from the different devices such as a computer to the Internet, or from device to device. The rate of transmission of data is measured by data rate of 10 to 1000 megabits per second. Most school use Ethernet.

LAN- LOCAL AREA NETWORK A school, office building or home will use a LAN setup. A LAN connects all the network devices over a short distance. LANs are usually managed, controlled and owned by a single person or organization. For example: In a school the students and staff will have to contact an individual on staff for their user name and password in order to gain access to the computers and the Internet.

WAN - WIDE AREA NETWORK WAN spans a large physical distance. The Internet is the largest WAN, spanning the Earth. WAN is a geographically-dispersed collection of LANs. A network device called a router connects LANs to a WAN. In IP networking, the router maintains both a LAN address and a WAN address.

DIFFERENCE BETWEEN LAN AND WAN Most WANs (like the Internet) are not owned by any one organization but rather exist under collective or distributed ownership and management. WANs tend to use technology like ATM, FRAME, FRAME RELAY and X.25 for connectivity over the longer distances.

LAN, WAN AND HOME NETWORKING Residences typically employ one LAN and connect to the Internet WAN via an Internet Service Provider (ISP) Some examples would include EASTLINK, BELL or Rodgers These service providers use a broadband modem. The ISP provides a WAN IP Address to the modem and all the computers on the home network use the LAN IP address. All the devices on the LAN can transfer data directly with each other. They however much go through a central gateway, which is known as a broadband router, which is used to reach the ISP.

Most common Network present in homes and schools today is the Wireless Local Area Network (WLAN). This is based on a WiFi wireless network technology

OTHER TYPES OF AREA NETWORK Metropolitan Area Network - a network spanning a physical area larger than a LAN but smaller than a WAN, such as a city. A MAN is typically owned an operated by a single entity such as a government body or large corporation. Campus Area Network - a network spanning multiple LANs but smaller than a MAN, such as on a university or local business campus. Storage Area Network - connects servers to data storage devices through a technology like the cloud. System Area Network - links high-performance computers with high-speed connections in a cluster configuration. Also known as Cluster Area Network.