November 12, 2017 - LSST’s fiber-optic network, which will provide the necessary 100Gbps connectivity to move data from the summit of Cerro Pachón to all LSST operational sites and to multiple data centers, came one milestone closer to activation last week; the AURA LSST Dense Wavelength Division Multiplexing (DWDM) Network Equipment that LSST will use initially was installed in several key locations. DWDM equipment sends pulses of light down the fiber to transmit data, therefore a DWDM box is needed at each end of a fiber network in order for the network to be operational. In this installation project, the Summit-Base Network DWDM equipment was set up in the La Serena computer room and in the communications hut on the summit of Cerro Pachón. The Santiago portion of the Base-Archive Network was also addressed, with DWDM hardware installed in La Serena as well as at the National University Network (REUNA) facility in Santiago. The DWDM hardware in Santiago will be connected to AmLight DWDM equipment which will transfer the data to Florida. There, it will be picked up by Florida LambdaRail (FLR), ESnet, and internet2 for its journey to NSCA via Chicago. The primary South to North network traffic will be the transfer of raw image data from Cerro Pachón to the National Center for Supercomputing Applications (NCSA), where the data will be processed into scientific data products, including transient alerts, calibrated images, and catalogs. The network will also transfer data from North to South, returning the processed scientific data products to the Chilean Data Access Center (DAC), where they will be made available to the Chilean scientific community.
The LSST Summit-Base and Base-Archive networks are on new fibers all the way to Santiago; there is also an existing fiber that provides a backup path from La Serena to Santiago. From Santiago to Florida, the data will travel on a new submarine fiber cable, with a backup on existing fiber cables. LSST currently shares the AURA fiber-optic network (connecting La Serena and the Summit) with the Gemini and CTIO telescopes, but will have its own dedicated DWDM equipment in 2018. Additional information on LSST data flow during LSST Operations is available here.