Hi, I have one-way audio issue with outbound calls via Telnyx Call Control (Voice API Application, not SIP). - Caller hears assistant clearly - Assistant receives only fragments of audio (very degraded) - Transcript shows only occasional sounds, mostly empty - Test calls in Vapi web interface work perfectly fine - Telnyx Voice API Application webhook: https://api.vapi.ai/telnyx/inbound_call - AnchorSite: Amsterdam, Netherlands Call ID: 019d199f-c5e7-7331-a933-0a8f60f8b4af Call link: https://dashboard.vapi.ai/calls/019d199f-c5e7-7331-a933-0a8f60f8b4af Timestamp: the whole call has issues Response I expected to receive: I expected the caller to be clearly heard Reponse I actually received: AI assistant doesn't hear me, sometimes partly and sometimes at all Extra screensohts from Telnyx settings: https://monosnap.ai/file/okVlqkVkU43p35YbtMqGawlcgB7KvY https://monosnap.ai/file/uHIJ6tqGkGjeORIkBu8nNP6tv0vHZj

This is almost certainly inbound RTP degradation from Telnyx → Vapi, not a Vapi issue since browser tests are clean. Your symptoms (clear downlink, broken uplink) usually mean codec negotiation fallback or bad RTP routing, lock Telnyx to PCMA (G.711A) only, disable transcoding, and ensure 8kHz mono. Also check your Voice API app is pinned to the same region as your Amsterdam anchor and that RTP ports/IPs aren’t being rewritten or dropped (NAT/firewall). In Telnyx call inspector, look for packet loss/jitter on the inbound stream—anything >1–2% will cause exactly this fragmentation. One key question: are you using Telnyx media proxy or direct RTP, and what does the inbound codec + packet loss show on that call ID? @feneksof