TERENA was requested by some members to start an investigation into IP telephony in September 2001. The response was very positive and suggestions were made to coordinate the creation of a cookbook with recommendations for setting up IP telephony solutions at university and national level, providing information about protocols and interoperability of equipment, as well as integration with the existing international hierarchies for IP videoconferencing. For this reason, a number of people in the TERENA community with significant expertise in the area of IP telephony decided to undertake this task and to write this document hereinafter referred to as IP telephony Cookbook.