Your data network is more crutial today than ever before to your business. With fiber from your service provider and between your closets and category cable to provide signals to your phones and computers to enviromental controls and WIFI - your network is one of your most important systems these days.
Everything begins at the Main-Point-Of-Entry (MPOE) because this is where service providers install their D-markation points. Whether it is your local phone carrier or your local cable television provider this is where their lines terminate in your building. Even though these rooms are now a fraction of the size that they used to be they are still important and have to be designed to accommodate both present and future needs including incoming conduit size and needed wall space with plywood backboards that meet NFPA codes.
Main Distribution Frame and Intermediate Distribution Frames (MDF and IDF respectively) are where your valuable networking gear is located.