Generic Requirements and Design Considerations
for Fiber Distributing Frames

GR-449-CORE describes the general requirements for fiber distributing frames (FDF). Telcommunications service providers typically use an FDF to interface between the outside plant and the central office. An FDF provides fiber optic facilities a cost-effective frame capable of holding a high number of optical cables.

The document also describes design considerations for next generation FDF. Next generation FDF’s will need to be compatible with older equipment and even physical space or floor layout. System capacity was also considered such as termination capacity, cable rack capacity and fiber jumper trough capacity. GR-449-CORE defines FDF types using “generations”. For example Generation I has 1 to 648 fiber terminations per FDF bay, while Generation IV has 2880 or greater.

Optical performance requirements and objectives are also tested. Some examples of tests include

Front Plane Jumper Tracing, Removal, and Reinstallation Test – randomly selected jumper assemblies from the front plane are traced, removed, and reinstalled. These operations will be timed, and afterwards, the systems optical performance measured.
Rear-Plane Intra-Facility Fiber Optic Cables (IFC) Assembly Removal and Reinstallation Test – breakout assemblies from the rear-plane are removed and then securely replace without disturbing other cables on the frame.