Appendix B
Cable and Connector Specifications
The connectors used inside the system have been cleaned by the manufacturer and connected to the
adapters in the proper manner. The operation of the system should be error-free if the customer provides
clean connectors on the application side, follows the previous directions, and follows the listed
guidelines:
•
•
•
•
•
If the surface of the fiber-optic connector is not clean or does not have an even shine, repeat the process
Note
using a fresh surface of the alcohol pad.
LX/LH GBIC and MMF Cable Considerations
The following sections describe the things you should consider if you are using a Supervisor Engine 2
with a long wavelength/long haul (LX/LH) GBIC with 62.5-micron diameter MMF cable.
Patch Cord
When using the long wavelength/long haul (LX/LH) GBIC with 62.5-micron diameter MMF on links
that span more than 984 feet (300 meters), a mode-conditioning patch cord is required. You must install
the patch cord (Cisco product number CAB-GELX-625 or equivalent) between the GBIC and the MMF
cable on both the transmit and receive ends of the link.
We also recommend using a patch cord between the LX/LH GBIC and MMF cable for very short link
Note
distances (10 to 100 meters). Without a patch cord, the link can have an elevated bit error rate (BER).
The patch cord is required to comply with IEEE standards. The IEEE found that link distances could not
Note
be met with certain types of fiber-optic cable due to a problem in the center of some fiber-optic cable
cores. The solution is to launch light from the laser at a precise offset from the center by using the
mode-conditioning patch cord. At the output end of the patch cord, the LX/LH GBIC complies with the
IEEE 802.3z standard for 1000BASE-LX.
Patch Cord Configuration Example
Figure B-8
OL-10100-11
Clean the connectors using lens tissues before connecting to the adapters. Use pure alcohol to
remove contamination.
Do not clean the inside of the connector adapters.
Do not use force or quick movements when connecting the fiber-optic connectors in the adapters.
Cover the connector adapters to avoid contaminating the inside of the adapters while cleaning the
chassis.
Cover the connectors and adapters to prevent the inside of the adapters or the surface of the
connectors from getting dirty when not using the connectors.
shows a typical patch cord configuration.
Cisco 7600 Series Router Supervisor Engine and Route Switch Processor Guide
LX/LH GBIC and MMF Cable Considerations
B-19