I have the pinout at home. I will post it tonight.
It works nicely with a 3.3v MAX232 chip.. I have ordered this from:
Get part # A232DBH3v
This will give you a DB9 Serial plug that will convert to the inline console on the device.
I have been able to use this with many of these VoIP endpoints. Some do not have the serial port enabled (the RT31P2 is one I tried.).
I will post the chart of the ones I discovered so-far. Important to point out. The pinout for the D-Link VTA is NOT the same as the Linksys devices. Also, they use different baud rates.
The bootloader of the D-Link VTA-VR is not locked. That is, once you get your serial cable hooked up, power it up and you will be able to hit ESC to get into the "PSP boot" bootloader. From here, you can load-in new firmware, change partition info, etc. This is vital if you plan to do any firmware testing.
Hope this helps..