Phone systems have been long forgotten in favor of more modern technology. The phreakers of the past left us a wealth of information, however while moving forward the environments as a whole have become more complex. As a result they are often forgotten, side tracked or neglected to be thoroughly tested. We’ll cover the VoIP landscape, how to test the various components while focussing on PBX and IVR testing. The security issues that may be encountered are mapped to the relative OWASP category for familiarity. Moving on I’ll demonstrate other fun ways that you can utilize a PBX within your future offensive endeavours.