  Large low earth orbit (LEO) satellite networks such as SpaceX's Starlink
constellation promise to deliver low-latency, high-bandwidth Internet access
with global coverage. As an alternative to terrestrial fiber as a global
Internet backbone, they could potentially serve billions of Internet-connected
devices. Currently, operators of CDNs exploit the hierarchical topology of the
Internet to place points-of-presence near users, yet this approach is no longer
possible when the topology changes to a single, wide-area, converged access and
backhaul network.
  In this paper, we explore the opportunities of points-of-presence for CDNs
within the satellite network itself, as it could provide better access latency
for users while reducing operational costs for the satellite Internet service
providers. We propose four strategies for selecting points-of-presence in
satellite constellations that we evaluate through extensive simulation. In one
case, we find that replicating web content within satellites can reduce
bandwidth use in the constellation by 93% over an approach without replication
in the network, while storing just 0.01% of all content in individual
satellites.
