[Asterisk-Users] Modem and Fax over VoIP

[Eduardo Goncalves]

Hello,

	I have the fowling scenario:

fxs[asterisk1]-----iax-----[asterisk2]e1----e&m---PSTN
	
	I want to know the steps to transmit fax from a machine connected to the fxs to a fax machine on the PSTN. The same for dial-up's.
	Is it possible only with a/ulaw ? 
	What configs I need in asterisk1?

Thanks in advance
Eduardo