FAX: PSTN -> VoIP -> PSTN

Hi guys, I’m sorry if this has been asked before but I couldn’t find anything on it.

I’m trying to be clever with fax machines. I would like to have multiple fax machines all with there own PSTN connections and route calls via Asterisk to a queue that has the 3 external PSTN numbers as static agents. Now I can get the inbound call to route to the pstn numbers however the recieving fax machine never recieves any faxes. My guess is that there is some issue with modulation over PSTN->VoIP->PSTN. Has anyone found a way to solve this or am I destined to have to use a hardware solution like installng a FXS card into the server (or similar), will a fxs card actually solve my issue, ie. has anyone done this?

Many thanks

Dave.