If you can hear the recipient but they cannot hear you (or vice versa), the issue is likely related to Network Address Translation (NAT) or firewall restrictions. Try enabling in the advanced network settings of your Zoiper account configuration, or forward the SIP ports (usually UDP 5060) on your router. Registration Failure
Supports call transfer (attended and unattended), call recording, conference calls, and voicemail notifications. i--- Zoiper Classic 2.43 Download