Availability of Connections in Ethernet over DWDM Core Networks

This paper investigates the availability of connections in core networks which use Ethernet directly over the optical DWDM layer. We study transparent, opaque and hybrid connections. We show that the availability of a protected hybrid connection can be accurately estimated through calculating the availability of a protected transparent path or protected opaque path. The selected optical node architecture has even a higher influence on the reliability compared to the choice to route opaque or transparent. To achieve availabilities over 99.999% - often required by providers - is only possible if the end nodes are completely doubled.