Chapter 2: Network Requirements2-26H128-08 and 6H129-08 User’s Guide2.3 100BASE-TX NETWORKThe 6H12X-08, with an FE-100TX installed in ports 7 or 8, provides anRJ45 connection that supports UTP cabling with an impedance between85 and 111 ohms. The device at the other end of the twisted pair segmentmust meet IEEE 802.3u 100BASE-TX Fast Ethernet networkrequirements for the devices to operate at 100 Mbps. Refer to theCabletron Systems Cabling Guide for details.2.4 100BASE-FX FIBER OPTIC NETWORKPorts 7 and 8 of the 6H12X-08 support the Cabletron Systems FE-100FXand FE-100F3 fiber optic interface modules. The device at the other endof the fiber optic segment must meet the 100BASE-FX Fast Ethernetnetwork requirements to operate at 100 Mbps. Refer to the CabletronSystems Cabling Guide for details.Multimode Mode Fiber Optic Cable LengthThe maximum multimode fiber optic cable length of a 100BASE-FXsegment is covered in the Cabletron Systems Cabling Guide.Single Mode Fiber Cable LengthsThe maximum single mode fiber optic length of a 100BASE-FX segmentmay be no more than 5 km between Data Terminal Equipment (DTE toDTE) in half duplex mode or 20 km (DTE to DTE) in full duplex mode.NOTEThe 6H12X-08 with an FE-100TX installed is capable ofoperating at either 10 or 100 Mbps. The FE-100TX canautomatically sense the speed of the other device and adjustits speed accordingly. For details, see Appendix B. If operatingat 100 Mbps, the cable must be Category 5 compliant with animpedance of 85 to 111 ohms.NOTEThe 6H128-08 has six fixed SC fiber optic ports designed foruse with multimode fiber. The 6H129-08 also has six fixed SCfiber optic ports, but it is designed for use with single modefiber optic cabling. Use of the wrong cabling can cause networkproblems.
