I've got this error for almost a month now. I've tried getting a new vapi number but still same results 2d4047cd-a663-48e0-9e09-2b50cc8dfbb6 d1122027-ea19-488b-8429-f3ebca1b7691 528ee784-3f37-4147-83c5-2f2a9a39b8e5 290a271b-193e-43e2-a49e-4a063ce84f35 c65cd138-bd00-40ff-8390-e07b84854350 74703711-206c-42fa-bfbf-bd19ec52e0b9

Switch over to a Twilio number and import the number to VAPI meticulously

## Check SIP Configuration and Network Settings This error occurs when your telephony provider doesn't respond in time or there's a SIP configuration issue. Start by verifying:

1. Check SIP URI format in forwardingPhoneNumbers array
2. Ensure firewall/NAT allows SIP traffic
3. Verify SIP server accepts calls from Vapi
4. Check authentication credentials if required

If issues persist, examine telephony logs and contact Vapi support with your call IDs. Sources: - [Discord Channel](https://discord.com/channels/1211482211119796234/1336713212233515089) - [Discord Channel](https://discord.com/channels/1211482211119796234/1340144301132353637)

Hey Zipsun, thanks for bringing this up. I am putting your thread in the investigation, and will get back to you with the proper RCA.

Thanks @Shubham Bajaj

In the pcap file, I observed HTTP status codes indicating 403 Forbidden, 408 Request Timeout, and 503 Service Unavailable. I am unable to determine the root cause of these issues and have sought input from my team to identify the underlying problem. https://cdn.discordapp.com/attachments/1367089001869213727/1367531718785106050/image.png?ex=6814eca9&is=68139b29&hm=261787d0edec6c252e48628eef7897eb77357187c7a7c1651556b3937463ad2d& https://cdn.discordapp.com/attachments/1367089001869213727/1367531719074250803/image.png?ex=6814eca9&is=68139b29&hm=f1b76ecc5bb910074ce0335f38296252f23ec4c6fe1fdb638861d7958b720ffd&

Okay gotcha, thanks for the update @Shubham Bajaj. It's kinda weird coz I also submitted a ticket about getting "sip-telephony-provider-failed-to-connect-call" errors on march and it got fixed but now it came back with a similar error "call.in-progress.error-sip-telephony-provider-failed-to-connect-call". I appreciate the prompt response from the team

We received a 404/408 from the destination we were trying to reach. can you check the phone numbers. https://cdn.discordapp.com/attachments/1367089001869213727/1369059840315359273/image.png?ex=681a7bd5&is=68192a55&hm=4a0a8a2c43c6ee78f6db0d5a081bc7271e9d46a35ad739f0ce038e8bbc725123& https://cdn.discordapp.com/attachments/1367089001869213727/1369059840558895104/image.png?ex=681a7bd5&is=68192a55&hm=8173b3e5e012bf5eeffcb5c2c9aa64f5149438150ad1b2529c5e4ebbc2102ae2&

Hello, error still persist

@gypson The error process is due to unreachable numbers. Check with your telephony to see why these numbers aren't connecting. This issue only affects the destination numbers you're trying to connect, and it hasn't been reported by other users. I suggest you check with your telephony and let me know your thoughts. We can brainstorm and contribute to resolving it if it's a VAPI issue.

It's working well now, thanks @User

No problem!