How much do you know about packet switching? Definitely, this term will appear in Cisco CCNA certification exam. There are many new terms to learn, most of which are ambiguous words at first. An example of these is packet switching. This term is absolutely needed to fully understand in order to pass a Cisco CCNA certification exam. This article aims to clearly define and explain terms such as packet switching and how it is compared to message switching.

Basically, packets from "point A" to "point B" will naturally transmit to the same point of destination, but through packet switching, they do not necessarily take the same route to its final goal. – These packets will take different paths, but in the end, they will successfully reach the destination. The packets are then reassembled to take the form of the original message.

Similarly, packet switching is a message switching that uses short messages. If the message is too lengthy and exceeds a network-defined maximum length, it will be automatically divided into shorter units, called packets, for transmission; the packets, each with an associated header, are then transmitted individually through the network. However, the basic difference in packet communication is that the data is formed into packets with a pre-defined header format (i.e. PCI), and well-known "idle" patterns. They occupy the link if there is no data to be communicated.

The “idle patterns” are discarded between packets through the packet network equipment and processes the entire packet as one piece of data. It simply investigates the packet header information (PCI) and then either removes the header directly (in an end system) or forwards the packet to another system. If the out-going link is not accessible at the moment, then the packet is placed in a queue until the link becomes free. A packet network is created by links which purposely connect packet network equipment.