What is the cable configuration (pinout) for the 9 pin to 25 pin command port cable?

A standard (9 pin to 25 pin) serial cable will work, but a minimum of pin 2 (transmit), pin 3 (Recv) and pin 7 (Signal Ground) is required.

STANDARD CABLE:

PC Serial Port (DB9F) MultiVOIP (DB25M)

1-------------------------------- DCD ----------------------------------8
2----------------------- Receive Data -----------------------------3
3----------------------- Transmit Data -----------------------------2
4-------------------------------- DTR ---------------------------------20
5----------------------- Signal Ground ----------------------------7
6-------------------------------- DSR ----------------------------------6
7-------------------------------- RTS ----------------------------------4
8-------------------------------- CTS -----------------------------------5
9---------------------------------- RI ------------------------------------22