iQoS is an open source software that evaluates quality of service metrics (Bandwidth, Jitter, Latency, Packet Loss) in Voice Over IP. It can predict de voice quality and the behavior of a VoIP call in both endpoints. For demo please select both eth0 interfaces. Video demo:
https://www.dropbox.com/sh/d682hqgg3q6uzi5/AACXaLJS2QiZeUe38...