If you read posts in this thread, there seems to be some works in progress to unlock this PAP2v2. Apparently, a PAP2v2 is a TI-chipset based ATA device running @160MHz with 8/16MB Flash/RAM. Looking through its firmware, I believe one can swear that this PAP2v2 firmware is based on a Linksys WRTP54G firmware source code. If this is the case and the device can be unlocked, I believe it is time to start porting the WiP WRTP54G firmware code to this PAP2v2 along with an asterisk. A PAP2v2 + asterisk should be able to outrun a Linksys SPA9000 in term of price and performance.

Holly cow. This got posted a week ago and read by more than 100 readers, yet not response whatsoever. Looks like no one is interested or don't dare to take the challenge.

This is an interesting proposal. In hardware, is it possible to turn one of the FXS port on PAP2 to FXS, so that it could become a PSTN to VOIP gateway?

I don't think you can do that unless you physically modify the hardware or add/connect an FXS2FXO adapter to one of the FXS port.

BTW, this PAP2 v2 is currently unlockable using this CYT30 unlocker. If you are lucky, your local BestBuy stores may still have this PAP2v2 (or PAP2 or SPA2002ER) for US$10/each after the instant US$50 Gift Card (OK, you will need to pay the first unit $60+Tax and use the GC to purchase subsequent units by paying the diffrerence, ie. $10 + Tax). This promotion of an instant US$50 GC probably will end by 8/19/6 (today). For about $10/each, this device is definitely not a bad investment to hack, let alone running an asterisk on it.