Cisco Catalyst X4232 Installation And Configuration Note page 12

Gigabit Interface Converters
GBIC Optical Power Characteristics
Table 8 provides the optical power characteristics of the GBIC.
Table 8
Parameter
Transmitter output power (min/max) 0/–9.5 dBm
Receiver maximum input power
Receiver sensitivity
Channel insertion loss:
GBIC Cabling Restrictions
You must observe the following optical-fiber cabling restrictions when using GBICs:
•
•
•
•
Installation and Configuration Note for the Catalyst 4000 Layer 3 Services Module
12
GBIC Optical Power Characteristics
50/125 micron MMF
62.5/125 micron MMF
9/10 micron SMF
The minimum cabling distance for 1000BASE-SX and 1000BASE-LX/LH GBICs is 6.5 feet
(2 meters).
When using the 1000BASE-LX/LH GBIC with 62.5-micron diameter MMF, you must install a
mode-conditioning patch cord between the MMF fiber-optic network and the GBIC whenever the
link distance is less than 100 meters or greater than 300 meters. For distances less than 100 meters,
the mode-conditioning patch cord reduces the amount of optical power coupled into the MMF. For
link distances greater than 300 meters, the mode-conditioning patch cord reduces differential mode
delay by offsetting the laser light. The mode-conditioning patch cord (CAB-GELX-625 or
equivalent) is required to comply with IEEE standards. The IEEE found that link distances could
not be met with certain types of 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 of the
patch cord, the LX/LH GBIC is compliant with the IEEE 802.3z standard for 1000BASE-LX.
You must insert a 10-dB inline optical attenuator between the single-mode fiber-optic network and
the receiving port on the 1000BASE-ZX GBIC at each end of the link if the link length is less than
15.5 miles (25 km).
You must insert a 5-dB inline optical attenuator between the single-mode fiber-optic network and
the receiving port on the 1000BASE-ZX GBIC at each end of the link if the link is greater than
15.5 miles (25 km), but less than 31 miles (50 km).
1000BASE-SX 1000BASE-LX/LH
(WS-G5484) (WS-G5486)
–3/–9.5 dBm
0 dBm –3 dBm
–17 dBm –19 dBm
3.4 dBm 4.4 dBm
3.2 dBm 6 dBm
n/a 6.5 dBm
1000BASE-ZX
(WS-G5487)
0/4.77 dBm
–3 dBm
–23 dBm
N/A
N/A
21.5 dBm
78-10164-03