Hi Jens,
Just to add to what Toni has said. Connections are not actually good representations of traffic. Take RTSP for example. One RTSP stream will actually have 5 connections associated with it:
RTSP channel
RTP video channel
RTCP video sync channel
RTP audio channel
RTCP audio sync channel
The converse of this is one RTMP connection can actually have multiple streams associated with it. So you could be doubling your traffic without ever seeing an increase in connection count.
This is why most of the events that are used revolve around streams, as they are the logical representation of "client connections".
Hope this helps clear things up!
Bryan