Chapter 7

4 Layers of TCP/IP Reference Model :

1. Application layer - enables client application programs to access the other layers an defines the protocols that applications use to exchange data. 2. Transport layer - responsible for providing the application layer with communication and packer services. 3. Internet layer - responsible for addressing, routing, and packaging data packets called IP datagrams. 4. Network Interface layer - responsible for placing packers on and receiving them from the network medium, which could ne any networking technology.

3. Metropolitan area network (MAN) -

A city or metropolitan area

Modem -

A device for translating as computers digital signals into analog form for transmission over ordinary telephone lines, or for translating analog signals back into digital form for reception by a computer.

Protocol -

A set of rules and procedures that govern transmission between the components in a network.

Search Engines -

A tool for locating specific sites or info on the Internet.

4. Wide area network (WAN) -

A transcontinental or global area

Packet Switching -

Technology that breaks messages into small, fixed bundles of data ands routes them in the most economical way through any available communications channel.

The connection medium for linking network components can be :

Telephone wire, coaxial cable, or radio signal (cellular/Wi Fi)

What is the Internet?

The Internet has become the worlds most extensive, public communication system. Its also the worlds largest implementation of client/server computing and internetworking, linking millions of individual networks all over the world. This global network of networks began in the early 1970s as a US Department of Defense network to link scientists and university professors around the world.

DSL -

Digital Subscriber Line - A group of technologies providing high-capacity transmission over existing copper telephone lines.

Domain Name -

English-like name that corresponds to the unique 32-bit numeric Internet Protocol (IP) address for each computer connected to the Internet.

Client/Server Computing cont.. :

Has largely replaced centralized mainframe computing in which nearly all of the processing takes place on a central large mainframe computer. Client/server computing has extended computing to departments, workgroups, factory floors, and other parts of the business that could not ne served by a centralized architecture. It also makes it possible for personal computing devices such as PCs, laptops, and mobile phones, to be connected to networks such as the Internet. The Internet is the largest implementation of client/server computing.

HTTP -

Hypertext Transfer Protocol - The communications standard used to transfer pages on the Web. Defines how messages are formed and transmitted.

IP Address -

Internet Protocol Address - Four-part numeric address indicating a unique computer location on the Internet.

ISP -

Internet Service Provider - A commercial organization with a permanent connection to the Internet that sells temporary connections to subscribers.

Client/Server Computing :

Is a distributed computing model in which some of the processing power is located within small, inexpensive client computers, and resides literally on desktops, laptops, or in handheld devices. These powerful clients are linked to one another through a network that is controlled by a network server computer. The server sets the rules of communication for the network and provides every client with an address so others can find it on the network.

RFID -

Radio-Frequency Identification - Technology using tiny tags with embedded microchips containing data about an item and its location to transmit short-distance radio signals to special RFID readers that then pass the data on to a computer for processing.

Network Operating System (NOS) -

Special software that routes and manages communications on the network and coordinates network resources.

Router -

Specialized communications processor that forwards packets of data from one network to another network.

A _____ _____ consists of two or more connected computers.

Computer network

Switch -

Device to connect network components that has more intelligence than a hub and can filter and forward data to a specified destination.

Bandwidth -

The capacity of a communications channel as measured by the difference between the highest and lowest frequencies that can be transmitted by that channel.

TCP/IP -

Transmission Control Protocol/Internet Protocol - Dominant model for achieving connectivity among different networks. Provides a universally agree-on method for breaking up digital messages into packets, routing them to the proper addresses, and then reassembling them into coherent messages.

2. Campus area network (CAN) -

Up to 1,000 meters (a mile) A college campus or corporate facility

Types of Networks : 1. Local area network (LAN) -

Up to 500 meters (half a mile) An office or floor of a building

Hubs -

Very simple devices that connect network components, sending a packet of data to all other connected devices.

VoIP -

Voice Over IP - Facilities for managing the delivery of voice info using the Internet Protocol (IP).