HTTP, on the other had, is a protocol that is used to request and deliver files such as Web pages and Web page components. When a browser requests a Web page from a Web server, it uses HTTP. 14. What is the difference between SMTP and MIME?

SMTP and MIME are both email protocols. SMTP is a transport protocol used for sending email. MIME, on the other hand, is a specification for formatting the email message itself, not for transporting the message.

15. What is the difference between Teleconferencing and Webcasting?

A teleconference can be a simple audio conference with one or both ends of the conference sharing a speaker phone. With additional equipment, a teleconference can be an interactive solution where multiple locations can be seen and heard. With webcasting, only one person presents while others view and listen to the presentation. A Webcast use streamlining media to distribute content and is therefore, better suited for delivery to a large audience if there are no requirements for interactivity.

16. What is the Physical Layer?

The Physical Layer is the first and lowest layer in the seven-layer OSI model of computer networking. The Physical Layer consists of the basic hardware transmission technologies of a network which are underneath the logical data structures of the higher level functions in a network.

17. How are digital signals (e.g. On the wire as measured on an oscilloscope) also in a sense analog?

Digital signals are non-continuous signals that change in individual steps while analog signals are continuous electrical signals that vary in time. However, a digital signal which is a discrete...

Give an example of half duplex communication.
An example of a half-duplex system is a "walkie-talkie" radio, where only one party at a time can transmit messages.

19. Which makes more effective use of available frequency FDM or TDM and why?

TDM makes more effective use of available frequency than TDM. Bit streams are transferred simultaneously as sub-channels in one communication channel, but are physically taking turns on the channel. The time domain is divided into several recurrent timeslots of fixed length, one for each sub-channel. On the other hand, FDM transmits signals over a common path by using a different frequency band for each signal.

20. What is the benefit of single mode fiber optics (using lasers) over multimode?

Single-mode fiber optics (using lasers) has advantages of greater bandwidth and reach for distances up to 50 times that of multimode.

21. What is the difference between serial and parallel communications?

Serial communication sends data one bit at one time, sequentially, over a communication channel or computer bus. In parallel communication, several bits are sent together, on a link with several parallel channels.

22. What is the difference between a MODEM and a CODEC?

A modem is a hardware device that can be either internal or external to a computer. It allows one computer to connect to another and transfer data over telephone lines. On the other hand, CODEC is software for compressing and decompressing audio and video files so that they don't take up so much disk space.