Explore Quality of Service (QoS) concepts in this comprehensive video lecture from the CCNA 200-301 course. Learn about IP phones, voice VLANs, and Power over Ethernet (PoE). Dive into QoS fundamentals, including queuing techniques, TCP global synchronization, and Random Early Detection (RED). Test your knowledge with five quizzes and gain insights into the Boson ExSim practice exams for CCNA preparation.