VoIP has two calls legs. Incoming and out-going. Different parameters refer to different call legs. For incoming call legs you will see the counters refused and accepted. For outgoing call legs you will see counter failed, successful,and incomplete.
dial-peer voice 123 pots
destination-pattern 123
max connections 5
voice-port 1:D
dial-peer voice 456 voip
destination-pattern 456
When a call comes from the telephony interface, port 0:D tries to make a call to some number (456),
the dial-peer 123 gets matched for the incoming call-leg and the dial-peer 456 gets matched for the outgoing call-leg.
Refused counter would get incremented if this call was one more than max connection defined under the dial peer (6th call).
Failed Counter would get incremented, if you are unable to reach phone 456 for any network reason
Incomplete calls are a subset of failed calls in order to maintain compatibility with existing network management applications.
Check out the CSCdr42851, it has some more explanations that you may find useful.
hope that helps
Javed
