  We present a high-order entropy stable discontinuous Galerkin (ESDG) method
for nonlinear conservation laws on both multi-dimensional domains and on
networks constructed from one-dimensional domains. These methods utilize
treatments of multi-dimensional interfaces and network junctions which retain
entropy stability when coupling together entropy stable discretizations.
Numerical experiments verify the stability of the proposed schemes, and
comparisons with fully 2D implementations demonstrate the accuracy of each type
of junction treatment.
