Length - Cabletron Systems 100BASE-FX Cabling Manual

Full-Duplex Fast Ethernet Network Requirements

Length

The 100BASE-TX standard specifies that any 100BASE-TX compliant device must
be capable of transmitting a Fast Ethernet signal not less than 100 m (328 ft) over a
UTP cable segment that meets the quality values listed above. As long as all
specifications are met for the entire length of the cable, UTP cable segments can be
run up to a maximum allowable length of 260 m (852 ft).
NOTE
8-4
As longer cables are more susceptible to noise and other
limiting factors, Cabletron Systems does not recommend the
installation of 100BASE-TX cabling over 100 m in length.
100BASE-TX