Allied Telesis AT-FS709FC - Manual (Page 16)

6
Maximum Distance
The maximum operating distance of the fiber optic port on the AT-FS709FC
Series Ethernet switch is 2 kilometers (1.25 miles). Cable lengths that exceed
this limit can result in poor or erratic network performance.
Note
The fiber optic port on the network device that you intend to connect to
the AT-FS709FC Series Ethernet switch must have the same operating
characteristics as the fiber optic port on the switch. For example, the
maximum operating distance and operating wavelength of the end
node’s fiber optic port should be the same as the switch’s fiber optic port.
For the technical specifications of the fiber optic port on the switch, refer
to “Technical Specifications” on page 21.