We are new to Asterisk and have issues making successful calls between SIP softphones connected via Asterisk. We would like to be able to communicate using cell phones connected on different 3G networks with different operators. We installed SIP phone software (such as linphone and others) and tried to make calls using many different client-side configuration settings (STUN/ICE enabled/disabled, etc.). The phone rings but there is no audio when call is answered. We are aware that it is most probably a NAT issue because everything works fine internally, inside LAN.
Asterisk is installed on a public IP (no LAN) without firewall with “nat=yes” (since clients are behind NAT) set in sip.conf
Any help would be greatly appreciated.