ManageEngine™ VQManager is a powerful, web-based VoIP monitoring software that aids in troubleshooting VoIP calls for failures & quality deterioration. It monitors devices that support SIP, H.323, Cisco™ Skinny & RTP/RTCP. VQManager passively monitors VoIP QoS metrics and generates alarms based on user-configured alert parameters. Over 30 comprehensive, pre-defined reports allow for complete analysis & optimization of your VoIP infrastructure....
[ 
Problems downloading? Read our
downloading guide 
Support for ManageEngine VQManager is available from the
publisher/developer site