84
A
PPENDIX
A: S
PECIFICATIONS
AND
C
ABLING
R
EQUIREMENTS
100BASE-TX Operation
100BASE-TX is the IEEE 802.3u standard for Fast Ethernet
signaling over Category 5 UTP or STP wire at 100 Mbps.
Based on an extension to the IEEE 802.3 Ethernet
specification, Fast Ethernet characteristics include:
■
A data rate of 100 Mbps.
■
A broadcast architecture.
■
A specific media-access control (MAC) scheme.
A wiring topology using 100BASE-TX specifies a wiring
hub, cable arranged in a star configuration, and Category 5
UTP or STP wiring. Each node has a separate cable run that
must not exceed 100 meters (328 ft) from the node to
the hub.
RJ-45 Connector Pin Assignments
The following illustration shows the RJ-45 connector pin
assignments for the EtherLink PCI NICs.
TX DAT
A
ACT
10
100
L
N
K
1 2 3 4 5 6 7 8
1
2
3
4
5
6
7
8
TD+
TD_
RD_
RD+
book Page 84 Thursday, July 29, 1999 12:23 PM