OSI Layers 0-3 Focus: Deep dive into Physical Layer (signal propagation, modulation, BER), Data Link (MAC protocols, switching, VLANs), and Network Layer (BGP, OSPF, EIGRP, MPLS, IPv6) functionalities. Using Riverbed Modeler (OPNET), you will simulate, troubleshoot, and optimize complex network scenarios, focusing on Physical (L1), Data Link (L2), and Network (L3) layers, including physical medium modeling (L0).