My ATA will not register after changing router.
Check DHCP/IP, DNS, cabling, SIP credentials and whether double NAT, CGNAT or firewall/ALG behaviour changed.
ATA IP; DNS; registration response; NAT layers; provider status.
VoIP provider/network engineer.
Show the technical detail
On a managed Wi-Fi plan
Keep ATA on Ethernet; review topology, do not expose credentials.
On another provider's router
ISP handles router/public IP; VoIP provider handles provisioning.
What to be careful of
Never request SIP passwords in plain chat.
Where this comes from: Official · see the original source ↗ · Draft—technical review · checked 17 August 2026