This course introduces the student to the fundamentals of telecommunication systems. Telephony systems and voice over internet protocol (VoIP) systems are used to explain such fundamentals. The topics include classification of telecommunication systems, traffic engineering and the concepts of trunking. Specifications of transmission and switching systems are introduced, and the design of non-blocking switching is practiced. For VoIP, the course covers the session initiation protocol (SIP) as well as the H.323 architecture. Link delay budgets are calculated for carrier grade VoIP systems.