Abstract

According to a growth of IP data traffic, demand on the direct accommodation of IP traffic by all-optical switching networks is increasing. Such architectures are being discussed in the Internet Engineering Task Force (IETF) and in the Optical Internetworking Forum (OIF). Considering network survivability against network failures, optical layer protection and restoration are indispensable functions for optical network equipments (ONEs), and a great deal of effort has been paid to the protection and restoration techniques.^1,2 So far, fast optical layer protection for the SDH network has been demonstrated in a 6,000 km WDM network by using the optical network protection equipment (ONPE), which has an automatic protection switching (APS) technique complied with the ITU-T G. 841 Annex A.³ The optical layer protection based on the APS technique is a promising as fast protection/restoration even in the IP-based optical switching networks.

© 2002 Optical Society of America