My internet phone has one-way audio.
One-way audio commonly points to NAT/firewall or blocked RTP media, not Wi‑Fi speed alone. Test the ATA/phone by Ethernet and review SIP/NAT design.
SIP registration; RTP directions; NAT/CGNAT; firewall; ALG; packet capture.
VoIP/network engineering.
Show the technical detail
On a managed Wi-Fi plan
Check WAN/public-IP model and local topology; engineering controls SIP ALG/ports.
On another provider's router
Contact VoIP provider and ISP with call timestamps.
What to be careful of
Do not open broad port ranges or disable firewall from a chatbot.
Where this comes from: Official · see the original source ↗ · Draft—technical review · checked 17 August 2026