1. Source Computer/Source Host Device where computer messages (data) originate (start from)

2. Receiving Computer/ Destination Host where data should arrive

3. Data Packet encapsulated bits (data) –Binary Digits –1s and 0s extra information added to ensure reliable communication –source address –destination address used to transport messages

4. Media Where the data packets travel STP, UTP, Coaxial cable, optical fiber, wireless –5 media studied in CCNA curriculum

5. Wireless Networking uses electromagnetic (EM) waves –these waves travel in a vacuum at the speed of light –in our atmosphere or in outer space –power waves, radio waves, microwaves, infrared light, violet light, visible light, ultraviolet light, x-rays, gamma rays

6. Protocols The rules that govern a specific layer of communication –A set of rules that make communication more efficient –Allows data packets to travel from source to destination without misunderstanding –Technical definition: A set of rules, or an agreement, that determines the format and transmission of data

7. Layer Protocols Network communication occurs layer-to- layer –Layer N on source communicates with Layer N on destination –The rules and conventions for this communication are called the Layer N Protocol

8. Evolution of Standards Mid 1980’s –Tremendous increase in the number of networks –Many different specifications and implementations –Proprietary systems in use blocked interoperability

9. Proprietary vs. Open Technologies Proprietary –Privately developed, owned, and controlled –One company or a small group of companies controls all usage of the technology Open –Free usage of the technology is available to the public

10. Interoperability The ability of networks to communicate & work together

11. ISO (International Organization for Standards) Researched network schemes currently in use Created a conceptual model to help vendors create networks that would work together –this model breaks a complex communication process down into smaller discrete parts 1984, released OSI reference model –A set of standards to enhance interoperability