Call is not getting connected

[sanddyreigns]

Hi! I am building AI Voice agents using Retell and for telephony using Vobiz.
But the issue is that, the workflow is getting executed properly it’s triggering the number is active.. even the retell node is getting executed but I cant able to receive the calls..
May I know why?

this is the retell Json

[
{
“call_id”: “call_48342c9869a18c83cb4fdf3c8de”,
“call_type”: “phone_call”,
“agent_id”: “agent_736dce9fb2de178a307890dfb4”,
“agent_version”: 1,
“agent_name”: “Dr. Khushal (INbound) (copy)”,
“retell_llm_dynamic_variables”: {
“customer_name”: “sandeep”,
“customer_problem”: “teeth pain”,
“today_date”: “2026-03-10”,
“today_time”: “11:19”,
“timezone”: “Asia/Kolkata”
},
“custom_sip_headers”: {},
“call_status”: “registered”,
“latency”: {},
“metadata”: {
“source”: “website_form”,
“lead_type”: “derma_clinic”
},
“call_cost”: {
“product_costs”: ,
“total_duration_seconds”: 0,
“total_duration_unit_price”: 0,
“combined_cost”: 0
},
“data_storage_setting”: “everything”,
“opt_in_signed_url”: false,
“from_number”: “+918037565222”,
“to_number”: “+919445508047”,
“direction”: “outbound”
}
]

also attached the image of the workflow

[support2]

Thank you for reaching out to Retell AI Support. We’ve received your ticket and our team will respond within 8 hours.

[support2]

Hi Retell,

Hi there,
To assist you with your telephony integration using Vobiz and Retell AI, please find the following resources:

• Video Tutorials: Access introductory videos for integration setup at Retell AI Docs: https://docs.retellai.com/videos/introduction
• Webinars: Watch detailed webinars on integration best practices at Retell AI YouTube Playlist: https://www.youtube.com/watch?v=A9H3a33gM2M&list=PLGrX1_bbFSHrD6DnoHnQw08nmAH_B3efs
• Forum Community: Join the community for real-time support at Retell AI Forum: https://community.retellai.com/invites/wzFwjPvch9
• Discord Community/Office Hours: Connect with our Discord for real-time assistance: https://discord.com/invite/wxtjkjj2zp
• Hire A Developer Program: Engage professional developers for personalized help via our Developer Form: https://retellai.retool.com/form/888fc4e3-fdd3-4de3-8434-d8ae68d35fc8
  Please review these resources, and let us know if you have any questions or need further assistance.

Best,
Evy AI
AI Support Agent @ Retell AI

[support2]

Hello,

Thank you for reaching out and sharing those details.

We investigated the call call_48342c9869a18c83cb4fdf3c8de and can confirm that Retell is correctly sending the outbound SIP INVITE to your Vobiz SIP trunk fdabb75b.sip.vobiz.ai. However, Vobiz’s server is responding with a SIP 500 Internal Server Error. This means that their server is encountering an issue when trying to process and route the call. This is why the call never connects. Looking at your call history, all outbound calls through Vobiz have failed (we see similar errors on earlier attempts as well), while your inbound calls have been working normally.
We’d recommend reaching out to Vobiz support to investigate why their SIP server is returning a 500 error for outbound calls from your trunk — it may be a configuration or routing issue on their end.

Additionally, we noticed your webhook URL for call events retell-call-events is returning a 404 error, which suggests your n8n workflow may not be active in production mode.

Regards,
Retell Support Team