Cisco 7609-S Installation Manual page 101

Appendix B Connector and Cable Specifications
WS-G5486
WS-G5487
OL-5079-04
The WS-G5486 GBIC (1000BASE-LX/LH) interfaces fully comply with the
IEEE 802.3z 1000BASE-LX standard. However, their higher optical quality
allows them to reach 10 km over single-mode fiber (SMF), versus the 5 km
specified in the standard.
The WS-G5487 GBIC (1000BASE-ZX) operates on ordinary single-mode
fiber-optic link spans of up to 70 km in length. Link spans of up to 100 km are
possible using premium single-mode fiber or dispersion-shifted single-mode
fiber. (Premium single-mode fiber has a lower attenuation per unit length than
ordinary single-mode fiber; dispersion-shifted single-mode fiber has both lower
attenuation per unit length and less dispersion.)
The WS-G5487 GBIC must be coupled to single-mode fiber-optic cable, which is
the type of cable typically used in long-haul telecommunications applications.
The WS-G5487 GBIC will not operate correctly when coupled to multimode
fiber, and it is not intended to be used in application environments (e.g., building
backbones or horizontal cabling) where multimode fiber is frequently used.
The WS-G5487 GBIC is intended to be used as a physical medium dependent
(PMD) component for Gigabit Ethernet interfaces, as found on various switch and
router products. It will operate at a signaling rate of 1250 MBaud, transmitting
and receiving 8B/10B encoded data.
When shorter distances of single-mode fiber are used, you might need to insert an
in-line optical attenuator in the link to avoid overloading the receiver:
Insert a 10-dB in-line optical attenuator between the fiber-optic cable plant
•
and the receiving port on the WS-G5487 GBIC at each end of the link
whenever the fiber-optic cable span is less than 25 km.
Insert a 5-dB in-line optical attenuator between the fiber-optic cable plant and
•
the receiving port on the WS-G5487 GBIC at each end of the link whenever
the fiber-optic cable span is equal to or greater than 25 km and less than
50 km.
GBICs use an SC-type connector to link the module to the fiber-optic cable.
Cisco 7609 Internet Router Installation Guide
Connector Specifications
B-7