Cisco Systems OL-7861-01 manual Gigabit Ethernet SFP Modules

Cabling and Specifications

•Always connect from transmit (TX) to receive (RX) when connecting GBICs to other equipment:

–Connect GBIC TX to equipment RX

–Connect GBIC RX to equipment TX

•Optical transceivers—such as the Cisco CWDM GBICs—have a maximum optical receive power, above which damage might occur to the receive diode. The incoming power level might be too high if the fiber lacks sufficient attenuation, which might occur in a short run of fiber (less than approximately 25 km). Attenuators are used to lower the incoming optical signal below the maximum optical receive power of the Cisco CWDM GBIC (–7 dB).

•When the length of the fiber-optic link is less than 15.5 miles (25 km), you must insert a 10-dB inline optical attenuator (Cisco product number AT-10DB-SC=) between the fiber-optic network and the receiving port on the Cisco CWDM GBIC at each end of the link to ensure that the maximum receive power is always less than –7 dBm.

Gigabit Ethernet SFP Modules

The Gigabit Ethernet laser optical transceiver module is a field-replaceable small form-factor pluggable (SFP) module that plugs into the receptacle on the Ethernet port adapter (EPA) located on the Modular Ethernet line card and provides the Gigabit Ethernet optical interface. (See Figure 35.) The module has two optical interfaces—laser transmit (TX) and laser receive (RX)—and an electrical interface (to the line card). The 4-Port Gigabit Ethernet ISE, 10-Port 1-Gigabit Ethernet, and Modular Gigabit Ethernet line cards use SFP modules.

Figure 35 SFP Module and Fiber-Optic Cable

CSA ID

PA

-

0 PA

- PA1

- 2

ACTIVE
LINK	0
RX
PKT
E P A	1
- 3 G E / S X / L H -	2
L C

	CT
	L I
	N K	0
	RX
	PKT
2	E P	1
	A
	- 3 G E / S X / L H -	2
3	L C

1Component side of line card

2Top surface of SFP module

1

98895

3Card carrier side of line card

Cisco XR 12000 Series Router Ethernet Line Card Installation

OL-7861-01 47