keeping SATCOM up makes perfect sense
@Ornis
@D.S.
Here is why network links are kept up. Suppose you have a scenario generating LOTS of ACARS messages in succession (e.g. AF447). If each message has to set up and tear down the link there is tremendous overhead added. Just setting up and tearing down a connection involves the exchange of a bunch of messages. When networks are designed a lot of attention is given to the most efficient use of resources to meet the design objectives of the network. We can rest assured that the keepalive ping is actually very efficient use of the sat link.
Just think how handy it is to have a SAT link up, whether you need it or not, all for the low, low cost of 1 ping each hour!
By the way, the computer you are reading this on is sending periodic keepalive messages so it can keep using the network address it currently has been assigned (assuming you are using DHCP and not a static IP address). It wants to avoid the extra headache of having its address expire and being forced to renew it. This is a very, very common practice in networking.