  A quantum internet holds promise for achieving distributed quantum sensing
and large-scale quantum computer networks, as well as quantum communication
among arbitrary clients all over the globe. The main building block is
efficient distribution of entanglement, entangled bits (ebits), between clients
with fixed error, irrespective of their distance. In practice, this should be
accomplished across multiple quantum networks, analogously to what the current
Internet does in conventional communication. However, existing quantum repeater
schemes for efficient distribution of ebits over long distances work only on
linear networks. Besides, there was no prescription on how to choose such
linear networks from quantum networks with arbitrary topology. Here we present
a practical recipe on how to aggregate quantum networks with arbitrary topology
in order to give clients ebits with fixed error efficiently, regardless of
their distance. This recipe is based on combination of two new concepts of
minimum cost aggregation and network concatenation. Our recipe forms the basis
of designing a quantum internet protocol for networking self-organizing quantum
networks to make a global-scale quantum internet.
