NAT Specialist for SIP Audio Issue

I'm experiencing a one-way audio issue with my SIP setup. I have a GOIP Gateway configured to forward calls to FreePBX/Asterisk. The setup works, but because devices are behind NAT, audio only travels one way. Your expertise is needed to investigate and advise on resolving this issue. Key points: - One-way audio issue - SIP phone is behind NAT - Potential loopback address issue ([login to view URL]) - Access to NAT router/firewall settings can be arranged Ideal Skills & Experience: - Expertise in NAT traversal - Familiarity with SIP and RTP protocols - Experience with FreePBX/Asterisk configurations - Network troubleshooting skills Please provide a detailed approach and estimated time for resolution.

Project ID: 39717986