T-Fuzz: Model-Based Fuzzing for Robustness Testing of Telecommunication Protocols

Telecommunication networks are crucial in today\´s society since critical socio-economical and governmental functions depend upon them. High availability requirements, such as the "five nines" uptime availability, permeate the development of telecommunication applications from their design to their deployment. In this context, robustness testing plays a fundamental role in software quality assurance. We present T-Fuzz - a novel fuzzing framework that integrates with existing conformance testing environment. Automated model extraction of telecommunication protocols is provided to enable better code testing coverage. The T-Fuzz prototype has been fully implemented and tested on the implementation of a common LTE protocol within existing testing facilities. We provide an evaluation of our framework from both a technical and a qualitative point of view based on feedback from key testers. T-Fuzz has shown to enhance the existing development already in place by finding previously unseen unexpected behaviour in the system. Furthermore, according to the testers, T-Fuzz is easy to use and would likely result in time savings as well as more robust code.