In this paper the problem of realization of a resistive

-port network from its paramount admittance matrix

is considered from a geometric point of view. Augmentation of the set of

ports to a linear

tree on a complete graph with

vertices leads to a system of

equations in

unknowns. All the real solutions of this system correspond to equivalent

ports. They may be looked on as points of a manifold

in the

-space

. The realization of Y in the conventional sense being constrained to non-negative resistor values is equivalent to finding a point of intersection of

and the non-negative orthant

of

. In this paper the theory of equivalence is studied and some properties of L are defined. Similarly to the known method of the decomposition of the admittance matrix Y of a resistive

-port network with

vertices into a unimodular congruence

, this paper proposes a decomposition of a general admittance matrix Y into a subunimodular congruence

.