In the telephony world VoIP is a hybrid.
A VoIP solution usually has dedicated Internet connections, dedicated T1 voice circuits, and at two or or more points in a call a digital to analog conversion.
On top of these common telephony components, you add the complexities associated with IP packets: latency, real time transport of packets, call control channels translations, and dial plan nuances.
One of the first questions to ask yourself when troubleshooting a VoIP call is whether or not a problem exhibits itself on all of your calls or just select ones.
In future posts we will begin to begin to isolate trouble to the various components of the call circuit and learn what clues to look for with each isolated issue or problem.