NURBS

Hi guys,

GLU NURBS seem to use:

degree + number of control points + 1 knots.

whereas other sources declare the amount of knots for NURBS to be:

degree + number of control points - 1 knots.

What is the difference? Why the extra 2 knots? And how are they applied over the control points?

Also, does the maximum multiplicity of a knot in OpenGL = degree+1? As opposed to degree times?

Thanks