Some SIP phones will simply ring when they receive an INVITE SIP message. However many phones will only ring when the INVITE message contains the extension that the phone is configured to use. This tool identifies how if a phone will ring on any extension, or when no extension is specified, or when a specific extension is given. It will also attempt to find out which extension rings the phone by performing a bruteforce attack. This tool is used together with “Ghost call” to automate the process.