Editing Main distribution frame (section)

{{Short description|Distribution frame where cables are cross-connected in telephony}}
{{more footnotes|date=June 2015}}
[[File:"Marine Cpl. Robert L. Hardin...checks the main distributing frame in Montford Point's headquarters for line difficultie - NARA - 532515.jpg|thumb|Small, single-sided MDF for a military base, 1940s]]
[[File:Jarretiere telephonie.jpg|thumb|Modern main distribution frame]]
[[File:Gigantic main distribution frame MDF at a central office.jpg|thumb|MDF at a central office with capacity for 67,000 users]]
In [[telephony]], a '''main distribution frame''' ('''MDF''' or '''main frame''') is a signal [[distribution frame]] for connecting equipment ([[inside plant]]) to cables and [[pair gain|subscriber carrier]] equipment ([[outside plant]]).