The Alcatel-Lucent 1660 SM Optical Multi-Service Node (OMSN) comprises next-generation STM-16/64 SDH equipment that integrates packet-switching functionality into a capable SDH system. It can be configured as a pure add-drop multiplexer or as a small cross connect. It provides STM-1/4/16/64 ports and a 384x384/256x256 STM-1 equivalent HO/LO matrix. Existing 1660 SM equipment with STM-16 interfaces can be seamlessly upgraded to STM-64. Meeting both metropolitan and regional network requirements, the 1660 SM is an ideal multiservice transport building block for delivering SDH, integrated ATM and Packet Ring MPLS-based switching capabilities, as well as LAN interfaces (Ethernet, Fast Ethernet and Gigabit Ethernet). Integrated Service Adapter (ISA) modules designed for ATM or Packet Ring switching and Ethernet or Gigabit Ethernet transport through the optical network can be equipped as needed. The main network applications of the Alcatel-Lucent 1660 SM are: SDH metro transport in both ring and meshed network architectures; Backhauling of 3G mobile and DSL broadband traffic; Metro Ethernet in MAN and WAN; SANs. The Alcatel-Lucent 1660 SM offers an AU3/TU3 conversion feature to support SONET/SDH gateway capabilities (for cost-effective transportion and aggregation of non-concatenated SONET payloads) when OMSNs are deployed at the SONET/SDH boundaries. It provides unmatched performance for its footprint. Also, thanks to the full interoperability with the Alcatel-Lucent 1696 Metrospan product family, the 1660 SM allows for flexible and cost-effective Storage Area Network (SAN) and transparent data services, spanning SDH and WDM technologies.