For using the otional package PPP a null modem cable is needed.
It needs at least three wires. This is the pin layout:
male- female- female- male-
pins pins
25pin 9pin 9pin 25pin
8 +- 1 1 -+ 8
| |
3 | 2 ------------\ /------------ 2 | 3
| X |
2 | 3 ------------/ \------------ 3 | 2
| |
20 +- 4 4 -+ 20
| |
7 | 5 --------------------------- 5 | 7
| |
6 +- 6 6 -+ 6
4 +- 7 7 -+ 4
| |
5 +- 8 8 -+ 5
The plugs have to be soldered with the bridges shown above.