Network And

Synchronous and Asynchronous mode:

In telecommunication signaling within a network or between networks, synchronous signals are those that occur at the same clock rate when all clocks are based on a single reference clock. Synchronous communication requires that each end of an exchange of communication respond in turn without initiating a new communication.

An asynchronous signal is one that is transmitted at a different clock rate than another signal. Asynchronous operation also means that a process operates independently of other processes, whereas synchronous operation means that the process runs only as a result of some other process being completed or handing off operation.

Analog and Digital:

Analog communication employs continuous transmission of an electromagnetic wave form that varies in frequency and amplitude.

A digital communication system uses discontinuous transmission that may vary in frequency, amplitude and/or phase to represent binary data.

Simplex and Duplex:

A communications network can provide many types of service. The most basic type of service is known as simplex. This service provides one-way communication. Examples of this type of service are TV distribution, and the transmission of burglar alarm messages.

Most networks transfer data in two directions and are known as duplex communications links. Duplex links are classified as either full duplex or half duplex (also known as two ways alternate), depending upon whether both local and remote nodes may simultaneously transmit, or whether one must wait for the other to finish before starting transmission.

Serial and Parallel Transmission:

In telecommunication, serial transmission is the sequential transmission of the signal elements of a group representing a character or other entity of data. The characters are transmitted in a sequence over a single line, rather than simultaneously over two or more lines, as in parallel transmission. The sequential elements may be transmitted with or without interruption.

A parallel link transmits several streams of data (representing particular bits of a stream of bytes) along multiple channels (wires, printed circuit tracks, optical fibres, etc.).

Serial Line Internet Protocol (SLIP)and Point-to-Point Protocol (PPP):

SLIP and PPP are two communication protocols which allow a computer connected to a server via a serial line (such as a modem) to become an actual node on the internet. This allows you to run network applications on your home computer directly. While SLIP and PPP are largely similar, there are some key differences. PPP is a newer protocol, better designed, and more acceptable to the sort of people who like to standardize protocol specifications. PPP has some additional benefits. Unlike SLIP (which can only transport TCP/IP traffic), PPP is a multi-protocol transport mechanism. This means that PPP not only transports TCP/IP traffic, but can also transport IPX and Apple-talk traffic, to name just a few. Better yet, PPP lets you transport all of these protocols at the same time - on the same connection.

Hypertext Tranfer Protocol (HTTP) and File Transfer Protocol (FTP):

File Transfer Protocol, or FTP, is a protocol used to upload files from a workstation to a FTP server or download files from a FTP server to a workstation. It is the way that files get transferred from one device to another in order for the files