Fax over IP

Hi, So i am using a TDM410 with a FXS adapter. I currently get the modem signals from my printer fax if I call the extension within my network. but cannot send/receive faxes outside of it. I believe it has something to do with the current codec being used. I would like to switch the extension to g726. If someone could point me in the right direction about changing codecs that would be helpful.

Thanks :mrgreen:

You need G.711 to reliable send fax in band. G.726 (ADPCM) might just work, but you may find that it only works at lower transmission speeds.

Seems like codecs were not my problem as it was defaulted to ulaw (g711). I get a busy signal when trying to send out a fax. When i call the extension I do hear the modem sounds.