Intelligent inter-domain connection provisioning for multi-domain multi-vendor optical networks

We propose a semicentralized semidistributed network architecture based on active stateful path computation elements (PCEs) to intelligently provide end-to-end inter-domain connections in multi-domain optical transport networks supplied by different equipment vendors. A novel control entity, called an inter-domain communication control and management element (ICCME), is introduced into the architecture to achieve flexible distributed inter-domain control and centralized intra-domain management by integrating with "proactive" and "reactive" stateful capabilities. Inter-domain routing and signaling are completed with the collaboration of multiple ICCMEs in a peer-to-peer manner, which decentralizes highly intensive computation and signaling to multiple ICCMEs. In addition, we put forward a unified inter-domain communication protocol to eliminate the differences in private signaling message formats of various vendors' domains. We report a successful field trial of providing inter-domain connections across a commercial three-domain three-vendor optical transport network. Also, experimental results indicate that ICCME-based architecture performs better than previous schemes in terms of scalability, i.e., low average routing load of control entities and low average delay in establishing inter-domain connections, but results in higher message overhead and blocking probability.