IBM eServer 200 xSeries User Reference Manual page 73

Table 6. Ethernet RJ-45 connector pin-number assignments..
Pin Signal
1 + Transmit data
2 - Transmit data
3 + Receive data
4 Not connected
8 1
Pin
5 Not connected
6 - Receive data
7 Not connected
8 Not connected
Chapter 5. Installing options
Signal
59