https://vapi.ai/ logo
Join Discord
Powered by
SignalWire BYO SIP number outbound calls getting f...
# support
f
we tried to connect a byp sip number that we bought off of signalwire but when we connected it and placed calls they either wouldnt go through or the logs would say user busy on all of them. the process of adding the number was correct and after contacting signalwire support they said they faced the same issue with VAPI. it would genuinely be great help if you guys could fix this issue our business is built on vapi
c
Hi there, Thank you for your message. Our team is currently out of the office. We operate Monday through Friday, from 9:00 AM to 8:00 PM Pacific Standard Time (PST). We’ll get back to you as soon as possible during our normal business hours. If your message is urgent, please mark it accordingly or include “URGENT” in the subject line, and we’ll do our best to respond promptly. Warm regards, Vapi Customer Support Team
v
To resolve "User Busy" errors with your SignalWire BYO SIP trunk, ensure your gateway configuration uses the numeric IPv4 address of the SignalWire SIP server (not the hostname), and confirm SignalWire has allowlisted both Vapi SBC IPs: 44.229.228.186/32 and 44.238.177.138/32. Example gateway config:
Copy code
json
{
  "provider": "byo-sip-trunk",
  "name": "SignalWire Trunk",
  "gateways": [
    {
      "ip": "YOUR_SIGNALWIRE_SERVER_IP",
      "port": 5060,
      "outboundEnabled": true,
      "inboundEnabled": false
    }
  ]
}
This step addresses the most common cause of outbound call failures as described in the [SIP trunk credential troubleshooting guide](https://docs.vapi.ai/advanced/sip/troubleshoot-sip-trunk-credential-errors). Source: - [Troubleshoot SIP trunk credential errors](https://docs.vapi.ai/advanced/sip/troubleshoot-sip-trunk-credential-errors)
r
That sounds really frustrating, especially if your calling setup depends on it. The “user busy” response with BYO SIP trunks usually points to a routing, auth, or SIP header mismatch between SignalWire and Vapi. It should be possible to trace it by checking the SIP logs and trunk config on both sides. Are you authenticating the trunk via IP or username/password, and what does the INVITE response look like in the logs? @flux media
f
Im not sure about any of this but i asked my associate whose setting it up and he sent me a detailed email about all the issues. my previous support request was wrong and user busy apparently isnt the only issue
Subject: BYO SIP Trunk - Outbound Call Failed to Connect with SignalWire Hi VAPI Support, I am experiencing an issue with BYO SIP trunk outbound calling using SignalWire. I have confirmed with SignalWire support that the issue is on VAPI's end. Here is my setup: - Provider: SignalWire - SIP Domain: fluxmediamarketing-vapi-outbound.dapp.signalwire.com - Phone Number: +12056703181 - Credential ID: c8e49fb6-1d3e-4297-9418-c71aa2210945 - Phone Number ID: 58299159-e3c3-4769-b44e-090b571f1c76 The error I keep getting in call logs: "call.in.progress.error sip outbound call failed to connect" And when I fetch the call details via API: - sipReason: Domain unavailable - sipStatus: 404 - endedReason: call.in.progress.error-sip-outbound-call-failed-to-connect What I have already done: 1. Created SWML outbound routing script in SignalWire 2. Created SIP domain app in SignalWire 3. Set password for domain app 4. Whitelisted all VAPI IPs (44.229.228.186, 44.238.177.138, 44.211.181.180, 54.202.8 fluxmediamarketing-vapi-outbound.dapp.signalwire.com
4. Whitelisted all VAPI IPs (44.229.228.186, 44.238.177.138, 44.211.181.180, 54.202.83.248, 52.43.240.87, 34.212.51.219) 5. Enabled OPUS codec 6. Created BYO SIP trunk credential via API with both gateway IPs and SIP registration plan 7. Exited SignalWire trial mode and added credits SignalWire support confirmed: "I retested setting up a new VAPI SIP trunk and I'm seeing the same error. There appears to be an issue with VAPI's API for setting up new byo-sip-trunk style SIP trunks." Could you please investigate this issue on your end? It seems to be a bug with VAPI's BYO SIP trunk API. Thank you!
signalwire support told us to ask vapi support about this issue because they have the same problem
r
Thanks for sharing all that, super helpful. That 404 “Domain unavailable” usually means the SIP domain isn’t being reached or resolved properly, not necessarily that the whole trunk is broken. From what you described, I’d double-check how the SignalWire domain is mapped to your app and whether the INVITE (Request-URI / To header) matches what SignalWire expects that’s a common cause of this. Also worth confirming if you’re using registration or IP auth and that SignalWire is set up to accept that exact method. Since SignalWire was able to reproduce it too, there might be an edge case with the BYO SIP setup, but I’d want to verify the SIP flow first. Happy to dig into the logs with you and figure out exactly where it’s failing we can go through it together. @flux media
f
Hi VAPI Support, I'm experiencing an issue with outbound calls through a SignalWire SIP trunk. Here are my details: Setup: - Provider: SignalWire BYO SIP Trunk - SIP Domain: fluxmediamarketing-true-vapi-outbound.dapp.signalwire.com - SIP Gateway IP: 104.248.150.114 (resolved via nslookup) - Credential ID: e38f7db1-3424-4aff-a37f-e1b7c5c3c65f - Phone Number ID: 105a7942-94c9-4894-b8a3-716ec934350f - Phone Number: +12056703181 Error: call.in-progress.error-sip-outbound-call-failed-to-connect What I've done: 1. Created BYO SIP trunk credential with gateway IP 104.248.150.114, port 5060 2. Registered phone number with credential ID 3. Assigned an AI assistant to the phone number 4. Whitelisted VAPI IPs (44.229.228.186/32 and 44.238.177.138/32) in SignalWire 5. SignalWire SWML script is configured correctly for outbound routing Problem: Test calls fail immediately with the above error. No logs or transcripts are generated in the call detail. The call never reaches SignalWire. Could you please help identify why the SIP outbound call is failing to connect? Thank you!
PreviousNext
Powered by