10BASE-T
10BASE-T is an implementation of Ethernet which allows stations to be attached via twisted pair cable. The name 10BASE-T is derived from several aspects of the physical medium. The 10 refers to the transmission speed of 10 Mbit/s. The BASE comes from the term baseband, which means only Ethernet signals are transmitted on the medium. The T comes from twisted pair, which is the type of cable that is used.
10BASE-T uses the second and third pairs (orange and green) of the TIA-568B wiring standard:
RJ-45 Wiring (EIA/TIA-568B)
| Pin | Pair | Wire | Color
|
| 1 | 2 | 1
| white/orange
|
| 2 | 2 | 2
| orange/white
|
| 3 | 3 | 1
| white/green
|
| 4 | 1 | 2
| blue/white
|
| 5 | 1 | 1
| white/blue
|
| 6 | 3 | 2
| green/white
|
| 7 | 4 | 1
| white/brown
|
| 8 | 4 | 2
| brown/white
|
10BASE-T was the first vendor-independent standard implementation of Ethernet on twisted pair wiring. However, it was in fact an evolutionary development from AT&T StarLAN which had both 1 Mbit/s and 10 Mbit/s versions. 10BASE-T is essentially StarLAN-10 with the addition of the link-beat.
In the OSI model, 10BASE-T is at the physical layer. Ethernet encompasses both addressing at the data link layer and a number of physical-layer implementations. In this model, 10BASE-T is one of the possible physical layer standards for ethernet-- some others include 10BASE2, 10BASE5, and 100BASE-TX. Network layer protocols, such as IP, do not generally need to know whether they are being hosted on 10BASE-T or not, provided they know that they are being hosted on Ethernet.
See also
computer network, Ethernet, RJ-45, 25 pair color code
