Below cable usually used for terminal and printers being connected to serial ports.
DCE to DCE
DCE Terminal/Printer/Modem
.-------. .-------.
| 1 |--------Protective Ground---------| 1 |
| | | |
| 2 |<<<-TD----------------------RD----| 3 |
| | (Pins 2 and 3 are crossed) | |
| 3 |----RD----------------------TD->>>| 2 |
| | | |
| 4 |<<<-RTS--------------------CTS----| 5 |
| | (Pins 4 and 5 are crossed) | |
| 5 |----CTS--------------------RTS->>>| 4 |
| | | |
| 6 |----DSR--------------------DTR->>>| 20 |
| | (Pins 6 and 20 are crossed) | |
| 20 |<<<-DTR--------------------DSR----| 6 |
| | | |
| 7 |---------Signal Ground------------| 7 |
| | | |
.-------. .-------.
DB-25 DB-25