Issue 3 January 2008 13
If the equipment room does not have one, you must build a main distribution frame (MDF) that
connects the media gateways to the building phone network and to the public switched
telephone network (PSTN). The tasks include the following:
●Physical requirements and layout on page13
●Main distribution frame hardware installation on page17
If the installation will use a patch panel rather than a main distribution frame, use the procedures
in Chapter 3: Installing the patch panelon page 29.
Physical requirements and layout
Before installing the MDF and other equipment in the equipment room, ensure that there is
adequate space and there is a plan for placing the equipment.
Installation space requirements
Make sure there is adequate space for the following pieces of equipment:
●Sneak fuse panels and emergency transfer unitson page 13
●110-type hardwareon page 13
●Cable Slack Manager on page 14
Sneak fuse panels and emergency transfer units
You need about 8 inches (20 centimeters) of horizontal wall space for each column of sneak
fuse panels. Horizontal wall space must also be provided for emergency transfer units.
110-type hardware
The trunk/auxiliary field and the distribution field are mounted on the same wall. Each 110P-type
terminal block is 8.5 inches (21.6 centimeters) wide. Vertical patch cord troughs are 5.31 inches
(13.4 centimeters) wide and horizontal patch cord troughs are 23 inches (58.4 centimeters)
wide.
Each 110A-type terminal block is 10.8 inches (27.4 centimeters) wide; however, no horizontal
patch cord troughs are used and the blocks are shorter than 110P-type terminal blocks. This
allows the 110A-type terminal blocks to be stacked. Therefore, the 110A-type hardware requires
less space than the 110P-type hardware on a per-station basis.