Fast Ethernet Interface Processor (FEIP) Installation and Configuration 9
IEEE 802.3u 100BaseT Specifications
•100BASE-T4—100BASE-T, half and full duplex over Category 3, 4, or 5 UTP or shielded
twisted-pair (STP) cabling with four pairs; also called 4T+ or T2, which is 2-pair UTP over
Category 3 cable.
Each physical layer protocol has a name that summarizes its characteristics in the format
speed/signaling method/segment length, where speed is the LAN speed in megabits per second
(Mbps),signaling method is the signaling method used (either baseband or broadband), and segment
length is typically the maximum length between stations in hundreds of meters. Therefore,
100BASE-Tspecifies a 100-Mbps, baseband LAN with maximum network segments of 100 meters
(or 400 meters for 100BASE-FX).
IEEE 802.3u 100BaseT Specifications
This section provides specifications for IEEE 802.3u 100BaseT. Table 1-1 provides cabling
specifications for 100BaseTX FastEthernet transmission over UTP and foil twisted-pair (FTP), and
100BaseFX Fast Ethernet overfiber-optic cables. It also summarizes IEEE 802.3u 100BaseTX and
100BaseFX physical characteristics. Also see Figure 2.
Table1 Specifications and Connection Limits for 100BASE-TX and 100BASE-FX Transmission
Parameter 100BASE-TX 100BASE-FX Multimode 100BASE-FX Single Mode
Cable specification Category 51 UTP2, 22 to 24 AWG
1. EIA/TIA-568 or EIA-TIA-568 TSB-36 compliant.
2. Cisco does not supply Category 5 UTP RJ-45 cables. However, they are available commercially.
62.5/125 multimode optical fiber 9/125 micron single-mode optical fiber
Maximum segment
length (half-duplex)3
3. Data Terminal Equipment (DTE to DTE), see Figure 2.
100 m 412 m N/A
Maximum segment
length (full-duplex)3100 m 2000 m 10,000 m
Maximum network
length(half-duplex, one
repeater)4
4. DTE to Repeater to DTE, see Figure 2.
200 m 272 m N/A
Data rate 100 Mbps 100 Mbps 100 Mbps
Signaling method 4B/5B blockcoded, scrambled, with
MLT-3 line coding 4B/5B block coded, with NRZI
line coding 4B/5B block coded, with NRZI line
coding
Connector SC-type: dual simplex or single
duplex for RX and TX RJ-45 (ISO/IEC 60603-7:-1990 Single mode SC-type: dual simplex or
single duplex for RX and TX
Topology Star/hub Star/hub Star/hub