Packet loss on an oversubscribed tdma, contended, shared access cheap VSAT system is a result of too much traffic and not enough pipe. For an analogy think of a big office sharing a 5Mbps DSL line. A properly implemented dedicated geostationary link doesn't have packet loss except under sun transit events, extreme rain fade (for ku and higher bands), and when too many people try to stuff too much traffic through too narrow of a link without appropriate QoS.

From the point of view of an end user on a LAN at a site dependent on two way satellite it may not be possible for them to determine exact why they're seeing packet loss.