The evolution of Automatically Switched Optical Network (ASON) is in response to the challenges and requirements for operating today's optical networks. The ITU-T developed ASON provides the architecture to automate the connection and management of services within the network. The IETF developed GMPLS is a set of protocols that can be used to communicate between network elements and setup services. ASON networks can be segmented into domains, subnetworks or routing areas that share common switching technologies, addressing schemes or management responsibility.
Computing and setting up end-to-end paths for services that traverse multiple optical domains pose a number of problems for the operator. The IETF PCE architecture and functional components present a solution for computing paths across multi-domain optical environments.