The protocol testing technology used in the next generation Internet should satisfy some new challenges and requirements. This paper focuses on the test suite de-scription and test implementation techniques. TTCN-3 is chosen as the test suite description language and extended in both syntax and semantics to satisfy the requirements of protocol robustness testing. PITSv3,a protocol integrated testing system based on TTCN-3,is developed,and the extensions for robustness testing are implemented. Finally,two practical test applications are presented. The protocol testing technology used in the next generation Internet 互 satisfy some new challenges and requirements. This paper focuses on the test suite de-scription and test implementation techniques. TTCN-3 is chosen as the test suite description language and extended in both syntax and semantics to satisfy the requirements of protocol robustness testing. PITSv3, a protocol integrated testing system based on TTCN-3, is developed, and the extensions for robustness testing are implemented. Finally, two practical test applications are presented.