>The painful move from IPv4 to IPv6 suggests that this is unlikely. More likely is an overlay over IP, TCP, or even HTTPS.
GNUnet can function as an overlay and an _underlay_ simultaneously, quoting from the dissertation:
> GNUnet is an overlay network, as it is initially supposed to primarily operate over the existing Internet network. However, GNUnet does not assume that this is always the case. For example, GNUnet can also operate directly over WLAN or Bluetooth to create an ad-hoc wireless mesh network, and with the GNUnet “PT/VPN” subsystems we can run TCP/IP over GNUnet. So in this configuration, GNUnet would be an underlay network, a bit like MPLS or B.A.T.M.A.N. [NAL07]. In reality, we in fact expect to see both at the same time: some peers will run over the existing Internet, while others may connect to GNUnet on Layer 2.
GNUnet can function as an overlay and an _underlay_ simultaneously, quoting from the dissertation:
> GNUnet is an overlay network, as it is initially supposed to primarily operate over the existing Internet network. However, GNUnet does not assume that this is always the case. For example, GNUnet can also operate directly over WLAN or Bluetooth to create an ad-hoc wireless mesh network, and with the GNUnet “PT/VPN” subsystems we can run TCP/IP over GNUnet. So in this configuration, GNUnet would be an underlay network, a bit like MPLS or B.A.T.M.A.N. [NAL07]. In reality, we in fact expect to see both at the same time: some peers will run over the existing Internet, while others may connect to GNUnet on Layer 2.