Mr.SIP is a simple console based SIP-based Audit and Attack Tool. Originally it was developed to be used in academic work to help developing novel SIP-based DDoS attacks and then the idea has been converted into a fully functional SIP-based penetration testing tool. In the current state, Mr.SIP comprises 7 sub-modules named as SIP-NES (network scanner), SIP-ENUM (enumerator), SIP-DAS (DoS attack simulator), SIP-ASP (attack scenario player), SIP-EVA (eavesdropper), SIP-SIM (signaling manipulator) and SIP-CRACK (cracker).