Thanks for the detailed breakdown since inbound, OPTIONS, and auth are all working and your captures show zero INVITEs from Vapi AI, this really points to an outbound routing or trunk binding issue rather than a gateway problem. The fact that Vonage works instantly tells us the call is being created, but it’s failing before the SBC actually dispatches it. That usually comes down to credential-to-trunk mapping or route selection logic. I’d start by verifying org-level trunk binding and forcing a rebind while checking outbound dispatch logs. I’ve handled similar regressions before happy to look at it with you privately and help narrow it down properly. @giantmamba