A Framework for Label Preference in GMPLS Controlled Optical Networks

In GMPLS optical networks, the label (i.e., wavelength) selection process can be accomplished in a dynamic and distributed way by the RSVP-TE signalling protocol. In wavelength-continuous networks, the concurrent selection of the same label by distinct reservation attempts may lead to a connection blocking. In wavelength- convertible networks, the selection of a distinct label on each link may lead to a waste of wavelength converters, and thus to an increase of network cost and blocking probability. This paper presents label preference schemes that aim at improving the wavelength selection process during both provisioning and restoration phases. By exploiting the standard and novel RSVP-TE objects, reservation contentions are reduced in wavelength- continuous networks and converters are saved in wavelength-convertible networks.