Top-of-Rack
Top-of-Rack networking or ToR is a network architecture and design term than relates to high density switching deployed to each rack and interconnected with fiber to aggregation/distribution/core switching. The network devices often live at the top of the rack, to allow easy access for the fiber on trays above the server racks.
ToR switching design is used by Pipe Ten and its facility providers as part of the overall network design.