Using existing tools to diagnose problems in a VoIP environment is a complex and tedious job. Unlike generic protocol analyzers, Hammer Call Analyzer enables users to visualize signaling and voice quality problems in VoIP networks. For example, the unique call list and multistage call flow display features walk engineers through the legs of a particular call. In addition, Hammer Call Analyzer displays waveforms and the Stream Quality Signature for any call. These features allow engineers to visualize problems in the exchange of messages between the various devices and quickly solve them.