This module introduces participants to the role of the IP Multimedia Subsystems (IMS) in Next Generation Networking. It elaborates in details the IMS architecture, including charging, security, and Policy and Charging Control (PCC). Henceforth, it defines the prime IMS protocols such as SIP, SDP, and Diameter. The course provides an in-depth analysis of their role in the registration of the IMS and the procedures of session control. Finally, it offers a brief examination of a few applications empowered by the IMS.