Dear Vapi Support Team, I am integrating Plivo with Vapi to enable outbound and inbound call support. I have followed the instructions provided here(https://docs.vapi.ai/advanced/sip/plivo), but I am still encountering the error: "SIP gateway failed to ...". Could you please advise on what might be causing this issue and how I can resolve it? Your guidance would be greatly appreciated. Looking forward to your response. Best regards, Jin

Hi Jin! 👋 I see you're having trouble with the Plivo integration with Vapi and encountering a "SIP gateway failed to..." error. While I don't have the complete error message, I can definitely help you troubleshoot this integration issue. Based on the information I have, here are several potential causes and solutions for your SIP gateway connection issue: ### Network and Configuration Issues - **SIP URI Format**: Ensure that the SIP URI in the

sipUri

attribute within the

forwardingPhoneNumbers

array is correctly formatted and points to a valid Plivo SIP address. [According to our documentation](https://discord.com/channels/1211482211119796234/1211483291191083018/threads/1336713212233515089), incorrect SIP URI formatting is a common cause of connection failures. - **Network Configuration**: Verify that your network allows traffic on the SIP protocol and that any firewalls or NATs are configured to allow SIP messages to pass through. [Our troubleshooting guide](https://discord.com/channels/1211482211119796234/1211483291191083018/threads/1334919245468799007) notes that firewall issues or SIP ALG (Application Layer Gateway) settings could be interfering with SIP messages. - **SIP Server Configuration**: Make sure your SIP server or PBX is configured to accept calls from Vapi's servers and that it is not rejecting the incoming INVITE requests. ### Authentication and Credentials - **Authentication Issues**: If your SIP endpoint requires authentication, double-check that the credentials provided to Vapi are correct. [According to our documentation](https://discord.com/channels/1211482211119796234/1211483291191083018/threads/1334238882660618250), Vapi expects authentication credentials where the username must be your SIP username, and the password can be anything except the keyword "test."

Hey! To help track down this issue, could you share: - The call ID This would really help us figure out what went wrong!