Not sure its true of this one, but some groundstation networks use a bent pipe model, where the radio at the groundstation is doing a bare minimum and then forw

Not sure its true of this one, but some groundstation networks use a bent pipe model, where the radio at the groundstation is doing a bare minimum and then forwarding the data to a compute center located elsewhere. This gives you all the latency on the ground of getting from the physical groundstation site to another location, which could be quite far away, even opposite side of the globe if all the compute is in the same place. Edit: I see elsewhere in the thread that the ISS is using IP telephony over their geosynchronous satellite link. There's your latency.