Over the years, large scale data networks have undergone significant
change not only with respect to the volume and nature of the traffic
they carry but also in regard to the criticality of their role, and
the level of service demanded of them. WANs have evolved from simple,
best-effort and specialized data networks used by a few, into complex,
heterogenous, multi-layered, all-pervasive backbones guaranteeing an array
of critical services to a global user population.
Optical networks, with their
terabit-wide links and `cut-through', wavelength-routed architecture,
seem well-suited to implement unified and homogenous, yet
multipurpose networks to address the diverse data transport needs of the
future. In such a scenario, since optical networks would provide all the
services currently provided by separate networks, the issue of reliability
and availability becomes all the more critical.
Moreover, in most applications,
the unified transport network may be the only resource driving a user's
business. Therefore, network downtime, no matter how small, may entail
significant losses for the user. This paper
proposes a new scheme for fast signaling for restoration, based on Optical
Burst Switching (OBS), a unique, emerging
paradigm for optical network design . The paper
discusses various issues involved in implementing fast
restoration signaling in backbone transport networks. Existing schemes
are described and a new scheme for restoration signaling is then proposed.
Experiments to evaluate the proposed scheme
are described followed by a discussion of the results.