Here is a router graph using data from Tom.
The vertices are routers, and the edges are interconnections.
This graph has
81 vertices
114 edges
diameter of this router graph is 6
maximum degree 21.
Here are several layouts of the above graph using different algorithms.
Ideas of the algorithms:
Find the BFS tree rooted at the vertex with largest degree.
Assign the coordinates of children around the parent (with respect to the BFS tree)
with Gaussian distribution.
The parameter sigma in Gaussian distribution decreases as the distance
from root grows.
Apply a transformation, which moves the children vertices away from
their great parent vertex.
The details of the algorithms will be included in a new paper "graph visualizations" (in preparation).
Remarks on the pictures on the right.
The second figure is derived by using the same algorithms except
that the children vertices are spreaded evenly around the parent.
The Third figure is based on the second figure with additional application of barycenter
algorithms several times.
The fourth figure is obtained by a "expansion" algorithm. Here
two forces are used. One force is the "spring" factor having value 1 assigned to each edge.
The other force is the "flux" factor having the same value
assigned to each vertex.