(1) (
Main
Distribution
Frame) A wiring rack that connects outside lines with internal lines. It is used to connect public or private lines coming into the building to internal networks. In a telco central office (CO), the MDF is generally in close proximity to the telephone switch. See
IDF,
CDF and
wiring rack.
(2) (
Multiple
Domain
Facility) Hardware and microcode supplied by Amdahl that allows the running of multiple system images on a single processor complex. MDF was the first such implementation that did not depend on software such as VM/370 or VM/ESA.