Unit 1: Network Fundamentals — OSI Model, TCP/IP Stack

Unit 2: Data Link Layer — Framing, Error Control, MAC Protocols

Unit 3: Network Layer — IP Addressing, Routing Protocols (OSPF, BGP)

Unit 4: Transport Layer — TCP, UDP, Congestion Control

Unit 5: Application Layer — HTTP, DNS, FTP, Email Protocols

Unit 6: Network Security — Cryptography Basics, SSL/TLS