There are various ways that are employed to protect a local area network (LAN) from harmful threats, as discussed below. Encryption method is used to prevent unauthorized users from accessing classified information within a local area network. In addition, a proxy is used to filter out websites that contain harmful or irrelevant information from reaching a given network (Chaudhury, n.d). Besides, installing a spam filter helps to protect a computer in a network from junk mails. An antivirus is yet another crucial security feature in a network. It should be always updated for effectiveness.
Synchronous transmission is a type of communication system whereby signals are transmitted in real time such as in a phone call. On the other hand, asynchronous transmission is a transmission system that does not necessitate all involved parties be available simultaneously, such as electronic mail. The sender and the receiver do not have to be online at the same time to communicate (Hancock & Gallo, 2002).
The major difference between analog and digital signals is that analog communication involves representing a waveform as it is found in its original format. However, in digital communication, the wave is sampled at similar time intervals and then represented in terms of strings of zeros and ones (Garza, 2011). X-ON/ X-OFF are communication protocols that control the flow of information between computing devices that are connected in an asynchronous serial mode. XON means that a transmitter is on, whereas XOFF means that the transmitter is off.
Simplex is a mode used in communication whereby signals are sent in one direction only such as in radio broadcasting. On the other hand, duplex refers to a communication mode that involves simultaneous sending and receiving of data (Chaudhury, n.d). Serial transmission involves sending data one bit at a time in a single channel where as parallel transmission involves sending data of considerable bit length, such as eight bits at a time, over various parallel channels.
In baseband transmission, the whole bandwidth of a communication channel is taken up by a signal while in broadband transmission, various channels shares the capacity of one communication medium. Both serial line internet protocol (SLIP) and point-to-point Protocol (PPP) are ways of connecting to the internet (Chaudhury, n.d). However, SLIP connection is done manually while PPP connection is done automatically.
File Transfer Protocol (FTP) is a protocol that is used to transfer files form one computer to another in a network. However, HyperText Transfer Protocol (HTTP) is applied the in transfer of documents and files between web servers and a web browser (Garza, 2011). Transmission Control Protocol (TCP) is a transport layer protocol that is employed by computing devices in a network to guarantee delivery of transmitted data. On the other hand, Internet Protocol (IP) is a method of data transmission from one computing device to another over the internet.