The “test-cord” connections at the ends of the link (where the test equipment connect in) are defined by the quality of the reference cable:
- STANDARD-grade reference cables (normal off-the-shelf patch cables)
- REFERENCE-grade reference cables (special cables with superior connector alignment and endface quality)
It should be noted that EF mode controllers and extender cords are automatically considered as REFERENCE-grade.
Because REFERENCE-grade test cables provide a more quality connection than STANDARD-grade cables, REFERENCE-grade connections contribute less overall loss to the link budget calculation.
In addition, REFERENCE-grade cables also have different allowable losses based on fiber type: multimode vs. singlemode.