CallID: 019c9ba5-a2b2-755c-8b7d-5a109b27b62d I am experiencing multiple occurrences of the error call.in-progress.error-providerfault-outbound-sip-503-service-unavailable when attempting outbound calls through my SIP provider. However, my SIP provider does not recognize this error as originating from their side. They also reported unusual behavior: VAPI appears to be sending the call using a username formatted like an email address in the SIP INVITE, which they believe is incorrect and may be causing the call to be rejected. the correct is 8010365 and is sending marcos.candido@sunhub.academy Could you please help me investigate this issue and confirm whether the SIP INVITE is being formatted correctly, or if there is any misconfiguration in the SIP trunk settings?

Thank you for the details. Based on the documentation, the

authUsername

in your SIP trunk configuration should match the username expected by your provider (e.g.,

8010365

). If Vapi is sending

marcos.candido@sunhub.academy

instead, this could cause the

503 Service Unavailable

error you’re seeing, as the provider may reject the call due to a username mismatch ([Vapi SIP Trunk Documentation](https://docs.vapi.ai/advanced/sip/sip-trunk)). Could you please confirm what value is currently set for

authUsername

in your Vapi SIP trunk configuration? This will help determine if the misconfiguration is causing the issue. Source: - [Vapi SIP Trunk Documentation](https://docs.vapi.ai/advanced/sip/sip-trunk)

in the SIP trunk configuration the username setted is 8010365

pinging our team

Hi @Marcos Candido, Thank you for providing the call id. The logs say that you are trying to use this phone number id:

46705725-58ec-4fc8-8895-b86128c129fa

. However I am not able to find this id, is it possible that you might have deleted it? If yes, did adding it again fix the issue? if not, please provide me with hte new call ID so that I can look up further logs regarding the issue you are facing.

I had this error coming from my GSM gateway device. Check the devcie logs.. usually unregistered sip will cause this issue.