A demonstration of "sipautohack" scanning an internal network that has 3 SIP devices. For each SIP device that acts as a PBX (registrar) it then identifies the extensions by trying to guess commonly used extension names. For example 1234,2345, 5000,6000 etc. Once it identifies a valid extension such as 6001, it will try to identify neighboring extensions such as 6002,6003 etc. Finally it will try to crack the password for each extension on the PBX. In this example, the target PBX servers are Communigate Pro and Asterisk.