alt Hacker NewsIf the phone is behind a NAT firewall / router it may need external help to receive calls: https://support.aa.net.uk/VoIP_NAT
If the phone is behind a NAT firewall / router it may need external help to receive calls: https://support.aa.net.uk/VoIP_NAT
aa.net.uk a couple of months did actually break calls with badly configured DNS entries.