Hello Vapi Support Team, I am experiencing an issue with outbound calls initiated through the Vapi API, specifically from my Telegram bot integration. Calls are consistently failing with a 503 Service Unavailable error. Problem Description: When my application attempts to create an outbound call using the Vapi API, the call is initiated successfully on your end (I receive a callId), but it immediately ends with the endedReason: "call.in-progress.error-providerfault-outbound-sip-503-service-unavailable". This indicates a problem with your underlying telephony provider. Steps Taken to Troubleshoot: Confirmed that my VAPI_API_KEY and VAPI_ASSISTANT_ID are correctly configured and valid. Ensured that the phoneNumberId is correctly passed in the createCall API request. Attempted to configure the outbound settings for the specific phone number (+17192979473) directly within the Vapi dashboard UI, but the issue persists. Checked my Vapi account for sufficient credits, and credits are available. As a test, I also tried directly providing the phoneNumber (instead of phoneNumberId) in the createCall request, but the same 503 error occurred. I have since reverted this change. Relevant Information: Latest callId: b05a5e9b-0624-4fc1-bfb5-04d39a22d04d phoneNumberId in use: 0cb48e87-8793-49ff-ac37-a4408005020f Phone Number: +17192979473 assistantId: 6f82fa6a-7968-4665-a739-ea758536ba80 Could you please investigate why outbound calls from this phoneNumberId are consistently receiving a 503 Service Unavailable error from your telephony provider? Any guidance or resolution would be greatly appreciated. Thank you,

Hey, thanks for sharing your details. Our team will look into it and get back to you soon with an update.