I cannot find a FDDI concentrator that runs on -48 VDC. Is there a product I've missed? This shortage of DC-powered concentrators might explain some of the transient outages during power problems at MAE-East, perhaps?

The FDDI concentrators at MAE East (along with all the other AC-powered infrastructure equipment) are powered by a UPS with at least 5 hours of battery power. In addition, all customer equipment co-located at the 1919 Gallows P-1 MAE facility is powered by the UPS. Here's a note from the facilities manager for MAE East on the subject of power: --------------------- MAE East at 1919 Gallows Road P-1 level is configured as follows: - four (4) two hundred amp Lorain rectifiers. - three (3) 1600 amp battery stacks. - one (1) 30 KVA UPS system. - generator umbilical is installed for use with MFS owned 150 KW mobile generator when required. Generator can be on site within one hour and has sufficient fuel to run for 24 hours. All racks installed at MAE East are equipped with a multi outlet power strip with a dedicated 20 amp AC circuit to the UPS system. Therefore all customer electronics and all MFS equipment requiring AC power are provided with filtered AC power via the UPS and have a five hour battery reserve. In addition, all racks have a minimum of 15 amps DC power to a Hendry fuse panel. This panel is served via the DC power plant which provides a minimum of eight hours of battery reserve. The standard MFS offering does not include UPS power in the MAE facilities. At MAE East we have gone one better and provided all customers with UPS. This is a premium service provided at no additional cost. As a final note, we are about to begin construction to upgrade facilities at both 8100 Boone Blvd. and MAE East. This work will include the installation of a permanent 900 KW generator. --------------------- Steve