The IP Multimedia Subsystem (IMS), standardized by the 3GPP, is becoming deployed productively, such that many legacy circuit switched services must be migrated to the packet switched domain within the next few years. The project Performance in IMS and related Topics 6 (PIMS 6) focuses on two core aspects of this migration, namely Long Term Service (R)Evolution and IMS Performance and Security Issues. Its theoretical aspects include, but are not restricted to finding existing work in the respective area (e.g., state-of-the art, applicable standards, tools, and implementations) but concerns also development of new concepts and architectures. The practical part is devoted to implementation topics like, e.g., adaption, testing and evaluation of existing tools or the implementation of new prototypes.