The number of RTP packets sent by the remote end point to this
MG on this flow. Comparing this with the local number of RTP
packets received from the remote end point gives an indication
of how many incoming packets were dropped on this leg of the
call. This information is from RTCP packet. Not all endpoints
report this statistic, if it is not available it will be set to
zero. This statistic will not be available for signaling flows.