Thank you very much for your prompt reply Mike The problem is I could simply get everything working by buying a zaptel compatible card or a VoIP Gateway. However I would like to use the modem that I am developing since it does provides some additional features. Does that mean I could start my way reading about Zaptel and develop a modified version of Zaptel to control my modem ? Thanks for pointing me the way. Regards Alex To From: freeswitch-dev-bounces@lists.freeswitch.org [mailto:freeswitch-dev-bounces@lists.freeswitch.org] On Behalf Of Michael Jerris Sent: Wednesday, October 28, 2009 1:23 PM To: freeswitch-dev@lists.freeswitch.org Subject: Re: [Freeswitch-dev] Using a modem to connect ordinary phones You are better off creating a zaptel driver than re-creating all that work that has already been done. Mike On Oct 28, 2009, at 1:05 AM, Alex To wrote: Hi, I found the same topic created 2 years back in Oct 2007 but it doesn't seem to have the answer yet. I am quite new to FS and having a hard time reading the documentation. Someone could tell me: how would I use a modem and develop an Endpoint in FS that I could bridge the call from VoIP to PSTN. I am a hardware engineer, I am developing this modem and would want to use it with FS. I know that I could simply buy a VoIP Gateway or a zaptel compatible card and use OpenZap. Could someone point me out the direction for the following matters: 1. I feel that I need to develop an Endpoint module, like mod_sofia, mod_iax... that controls my modem so I could bridge the call from VoIP to PSTN ? If that is correct, could someone point me the documentation to start reading about Endpoint interface .? 2. Is there any similar module developed before about controlling a modem using AT Command