that time. Eg. the time of ARPANET and MILNET. 2. Message transmission protocols - TCP and UDP These form the base of message transmissions. You cannot go ahead without understanding these topics. 3. Understand IPv4 addressing 4. Domain Name Server (DNA) -Forward Look-up -Reverse Look-up -Zones -Resource Mapping 5. Types of Communication Networks This will include Wired communication and wireless communication. Also, try to focus more on satellite communication as this technology is at a boost right now! 6. Data - Flow in netwokrs Packet-Switching mechanism Circuit-Switching mechanism This will explain you how the data is broken down into multiple pieces and then transmitted across the network. Also, once received, how it is checked and combined to form the original message. Learn processes like Multiplexing, De-Multiplexing, FHSS, BSSS, etc. is important as they are/have been used in many communication technologies since a long itme now. 8. The 7-Layered OSI Model 9. Technologies like ATM, SONET, X.25 10. Understand how a router, modem, bus and bridge works in a network. 11. Understand IPv6 (the new generation) addressing 12. Install tools/softwares which will help you buld your own networks and test them virtually before actual implementation.