KKN
Based on my review of the underlying protocols there are a couple of candidates for "pings". There are requests to establish a comm link between the a/c and ground station via satellite that involve underlying requests to use a particular communication channel with an exchange of packets negotiating that connection (AMSS). Then there are keepalive packets (IDRP) exchanged once a connection is established that occur periodically. I suspect that there were 4 connection requests with more numerous keepalive packets exchanged in between. Of course this is conjecture. I have no way of knowing but someone does!
In the end, I suspect that BOTH are true - 4 pings of one kind and numerous pings of another kind.