  We consider the problem of embedding the Steiner points of a Steiner tree
with given topology into the rectilinear plane. Thereby, the length of the path
between a distinguished terminal and each other terminal must not exceed given
length restrictions. We want to minimize the total length of the tree.
  The problem can be formulated as a linear program and therefore it is
solvable in polynomial time. In this paper we analyze the structure of feasible
embeddings and give a combinatorial polynomial time algorithm for the problem.
Our algorithm combines a dynamic programming approach and binary search and
relies on the total unimodularity of a matrix appearing in a sub-problem.
