MOS (our overall VoIP Ready score)
The Mean Opinion Score assesses the packet quality for VoIP. The MOS ranges from 1-5 and generally any score above 4 signifies your connection is VoIP Ready.
Jitter occurs when a stream of packets from one caller to another is received incomplete or out of order and is measured in milliseconds of delay. Optimally you have no delay.
Packet loss measures by percentage how many packets were transmitted vs. received for both inbound and outbound media traffic. Since VoIP greatly depends on all media packets being delivered, even a very low percentage of loss may affect call quality.
Round Trip Time (RTT)
Round trip time is important as is measures the speed of a packet traveling to/from the caller to the voice gateway and back. Like jitter, it is measured in milliseconds and should always be less than 150ms.