This attribute counts the calls from the interface which were
rejected by the far-end. This rejection could be due to:
1) no free channels at the end-point, or
2) a voice call going to a data only VoiceRoute, or
3) a data call going to a voice only VoiceRoute, or
4) a signalling protocol incompatibility between end-points.
The value wraps to zero when it reaches its maximum.