Design and implementation of reliable multi-layer service network

This paper describes the design and implementation of the new Japanese academic backbone network, called SINET4, which started full operation in April 2011. The network was designed to serve as a higher-speed and more reliable infrastructure than the previous network, SINET3, as well as to provide a variety of multilayer network services. The network was subjected to the disastrous March 11 earthquake during the migration from SINET3 to SINET4 but did not suffer serious damage thanks to the new network design. We present the network design concept, networking technologies applied, and effects of the earthquake.