Checking real VoIP quality?

[vibrantdream3]

How do I check the real quality of VoIP traffic before signing a contract?

[winterbreeze14]

Usually I ask for a test account and make dozens of calls to different destinations, checking average call durations (ASR, ACD) and latency.

[starrynight11]

I listen to call recordings: if there’s persistent echo or disconnections, quality is lacking.