Warvox

Overview:
WarVOX is a free, open-source VOIP-based war dialing tool for exploring, classifying, and auditing phone systems. WarVOX processes audio from each call by using signal processing techniques and without the need of modems.[1] WarVOX uses VoIP providers over the Internet instead of modems used by other war dialers.[2] It compares the pauses between words to identify numbers using particular voicemail systems