Intuitive Labs is offering at this moment a time-limited by-invitation beta-trial without any warranties. If you are interested in the trial, proceed as follows:
Prerequsities: make sure you have administrative accesss to a Linux machine which stands in the path between the Internet and your VoIP equipment: router or a SIP PBX
Sign Up: Request an Account by clicking here.
Sign In: to see and analyze your SIP traffic.
That's all! You know have visibility in SIP calls, and you can block dangerous traffic without administering yet-another security appliance.