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CCNA Networking Fundamentals: Part 1

Posted in Cisco Certification with tags , , , , , , , , , , , , , , , , , , , , , on March 31, 2011 by jjrinehart

To have a complete knowledge needed to successfully achieve the CCNA certification, you and I need to have a good grasp of how networks move information from one place to another.  Since all the bits, bytes, masks, and rules can be confusing, I am a big fan of analogies, comparing the concepts to something more familiar.

Networking is really just communication,  namely, communication between electronic devices, which is similar to the process of a conversation.  In classic communication theory, you have the following elements in most situations:

1. Sender.  One individual is creating the information and initiating the conversation.  This person has a series of thoughts or ideas that he/she wants to convey to another person.

2. Receiver.  One individual is receiving the information being sent by the sender.  Ideally, the thoughts or ideas of the sender will be accurately reproduced in the mind of the receiving person.

3. Medium.  No, this doesn’t mean a psychic (nice try though), bur rather, the way in which the message is being sent and received.  In conversations, this is typically the air by means of sound.

All three of these elements actively participate in the actual communication process, which happens in the following manner.  Keep in mind that in a real conversation this process is repeated constantly, and the roles of sender and receiver switch back and forth:

1.  Thoughts: This/these are the concepts in the mind of the sender wanting to be conveyed.

2.  Words: Since humans are not usually psychic, the idea(s) have to be converted into a format suitable for transmission.  This is referred to as encoding.

3.  Transmission: Words are spoken audibly, creating sound waves which travel from the mouth of the speaker to the ear of the listener.  Hopefully he/she is paying attention!

4.  Reception: The receiver/listener hears the sound waves, and the words are interpreted in their mind.  This is the reverse process of #2, and predictably referred to as decoding.

5.  Thoughts:  Using the meaning(s) of the words, the receiver reconstructs the concept/idea in their mind, hopefully reflecting the original.

Sounds simple, right (no pun intended)?  Any of us that have been in any sort of significant relationship, however, can attest that many times the idea understood on the other end of the conversation isn’t even close to the same (“how does this dress make me look?”)  There are lots of things that can distort the message, including language (even accents), background noise, nature of the relationship, and cultural understandings.  The same is true with network communication, which we will look at in more detail in the next post.