Yeastar Certified Integration Specialist Free Online Training Course Taken entirely online, this free training course is the most convenient way for anyone who is interested in Yeastar P-Series PBX System or becoming a Yeastar Certified Integration Specialist to acquire particular skills to secure your PBX system. In this lesson, you will learn the following aspects of Yeastar P-Series PBX System： 1. Integrate Legacy PBX with Yeastar P-Series PBX 2. Interconnection Between 2 Yeastar P-Series PBXs For more technical training and certification services, please check: