The fourth chapter describes a detailed hierarchical routing GMPLS-based framework for provisioning all-optical DWDM optical networks.

But instead of taking a single path, light can bend around the object in one of two, or four different routes, thus doubling or quadrupling the amount of information scientists receive.

When light from a star passes near a galaxy, for example, its path bends, changing where the star appears in the sky-the so-called gravitational lensing effect.