B-13
Cisco 7600 Series Router Installation Guide
OL-4503-26
Appendix B Connector and Cable Specifications
Cable Specifications
An unconditioned launch, in the worst case, might concentrate all of its light in the center of the
fiber-optic cable, exciting only two or more modes equally.
A significant variation in the amount of DMD is produced from one MMF cable to the next. No
reasonable test can be performed to survey an installed cable plant to assess the effect of DMD.
Therefore, you must use the mode-conditioning patch cords for all uplink modules using MMF when the
link span exceeds 984 feet (300 meters). For link spans less than 300 meters, you can omit the patch cord
(although there is no problem using it on short links).
For link spans less than 984 feet (300 meters), you can omit the patch cord.
Note
We do not recommend using the LX/LH GBIC and MMF without a patch cord for very short link
distances of 33 to 328 feet (10 to 100 meters). The result could be an elevated bit error rate (BER).