The Cisco 1000BASE-EX SFP operates on standard single-mode fiber-optic link spans of up to 40 km in length. A 5-dB inline optical attenuator should be inserted between the fiber-optic cable and the receiving port on the SFP at each end of the link for back-to-back connectivity.
Fiber optic
1000 Mbit/s
SFP
Y
40000 m
1310 nm
1
Y
Cisco ME 3400, Cisco Catalyst 3750