Ethernet Version	Transmit Symbol Rate (Baud)	Encoding	Cabling	Duplex	IEEE Reference
10BASE-T(*)	10 MBd	Manchester (binary 1 = low->high, binary 0 = high->low transition in middle of a bit period	2 pairs of CAT 3 UTP	Full or Half	802.3
100BASE-T2	25 MBd	PAM5x5 (each nibble->2 quinery symbols {-2, -1, 0, +1, +2})	2 pairs of CAT 3 UTP	Full or Half	802.3 clause 32
100BASE-T4	33 Mbd	8B/6T (each octet->6 ternary symbols {-1, 0, +1})	4 pairs of CAT 3 UTP	Half only	802.3 clause 23
100BASE-TX(*)	125 MBd	4B/5B (each nibble->5 bit binary code)	2 pairs of CAT 5 UTP or Type 1 STP	Full or Half	802.3 clause 25
1000BASE-T(*)	125 MBd	4D-PAM5(each octet->4 quinery symbols {-2, -1, 0, +1, +2})	4 pairs of CAT 5 UTP	Full or Half	802.3 clause 40
1000BASE-CX	125 MBd	8B/10B (each octet->10 bit binary code)	2 pairs of 150-ohm STP	Full or Half	802.3 clause 39