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Agora builds the Conversational AI Engine that powers real-time voice agents. Its SIP Trunk vendor option lets you bring a phone number you already own, so you can run an Agora agent on a Vobiz number anywhere Vobiz operates.

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What you’ll build

A two-way setup on a single Vobiz number:
  • Outbound - the Agora agent places campaign calls through your Vobiz outbound trunk.
  • Inbound - calls to your Vobiz number route through an inbound trunk to the Agora agent.
Each direction uses its own trunk, so configure both.

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Architecture

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Prerequisites

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Step 1: Create an Agora agent

In the Agora Console, open Agents and click Create Agent. Pick your project, name the agent, and choose a template - Blank, Appointment Reminder, NPS Survey, Payment Reminder, IVR, Customer service for e-commerce, or Sales / Lead qualification.
Agora Create Agent panel with a project selector, agent name, and a list of starter templates
You’ll attach this agent to your number in both directions, so create it before wiring the trunks.

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Part 1: Outbound calls

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Step 2: Create a SIP credential in Vobiz

A Vobiz outbound trunk authenticates incoming traffic with a SIP credential, an IP access control list, or both. This guide uses a credential - it is the quickest route and stays valid if Agora changes its IPs. Go to Credentials List and click + Add Credential. Note the username and password - Vobiz stores the password hashed and does not display it again after creation. See Credentials List for the full walkthrough.
Prefer an IP allow-list? Agora publishes its outgoing SIP IPs per region on Set up SIP trunk. Take the set that matches your number’s country code and add it under IP Access Control List instead of - or alongside - the credential.

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Step 3: Create the outbound trunk

Go to Outbound Trunks and click + Create New Trunk. Attach the credential from Step 2 under Credentials.
Vobiz outbound trunk detail showing the SIP domain and an attached credential
The trunk details panel shows a SIP Domain in the form <trunk-id>.sip.vobiz.ai. Copy it - this is the address Agora sends outbound calls to. Each trunk gets its own domain and it is never shared.
Attach the credential to the trunk. Without either a credential or an IP ACL, the trunk has no way to authenticate traffic from Agora.

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Step 4: Add the phone number in Agora

In the Agora Console, choose Add Phone Number and set Vendor to SIP Trunk.
Agora Add Phone Number dialog with vendor set to SIP Trunk and fields for the SIP trunk address, transport protocol, username, and password
Although Agora marks the authentication fields optional, this setup needs them - they are what the Vobiz trunk checks.

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Step 5: Create a campaign

Outbound calls run as campaigns. Open Campaigns → Create New Campaign, then pick your agent, the number you just added, and upload a contacts CSV.
Agora Create New Campaign screen with a confirmation dialog summarising the campaign, phone number, agent, contacts, launch timing, and max call duration
Set Launch Timing, Call delay, and Concurrency limit to match your Vobiz account limits, then confirm the summary to launch. Outbound is now wired.

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Part 2: Inbound calls

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Step 6: Pick your regional origination URI

Agora terminates inbound calls on a regional SBC. Pick the one matching your number’s country code from Agora’s Set up SIP trunk page, which lists the current endpoints and outgoing IPs for every region:
Agora documentation listing regional SBC origination URIs for TLS and TCP/UDP alongside the country codes each region serves
Each region also offers a TLS endpoint on port 5061. Check the Agora page for the authoritative list - endpoints and IPs change there first.

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Step 7: Create the origination URI in Vobiz

Go to Origination URIs and create a URI pointing at the Agora SBC for your region.
Remove the sip: prefix. Agora presents the value as sip:sbc-ap-south.viblinx.com:5060, and the Vobiz URI field takes domain or domain:port. Paste sbc-ap-south.viblinx.com instead.
Go to Inbound Trunks and create a trunk with the origination URI from Step 7 as its Primary URI. Then click Link Numbers, select your Vobiz number, and confirm.
Vobiz inbound trunk detail showing the Agora primary URI and one linked phone number
The count updates to Linked Numbers (1) and inbound routing is live. Recording, transcription, and webhooks on this screen are all optional - see Callbacks for the webhook payloads.

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Step 9: Assign the inbound agent in Agora

Back in Agora, edit the phone number and open Inbound Settings. Set Inbound agent to the agent from Step 1.
Agora Edit phone number dialog with the inbound agent dropdown open and call duration and silence timeout settings below
Max call duration and Silence timeout are in seconds. Leave End call on conversation end and End call on silence on unless you have a reason to hold the leg open.

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Test the integration

  • Inbound - call your Vobiz number. The Agora agent should answer.
  • Outbound - launch a campaign with a single contact and call your own phone.
Check Call Logs in the Vobiz Console to see both legs.

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Troubleshooting

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Outbound calls are rejected with a 401 or 403

The trunk is not accepting the credentials. Confirm the username and password in Agora match the Vobiz credential exactly, and that the credential is attached to the outbound trunk and set to Active.

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Outbound calls do not reach Vobiz

Check the SIP Trunk Address is the trunk’s own SIP domain, in the form <trunk-id>.sip.vobiz.ai. Each trunk has a distinct domain.

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The origination URI is rejected when saving

Remove the sip: prefix. The field takes domain or domain:port.

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Inbound calls ring but never reach the agent

Confirm the number appears under Linked Numbers on the inbound trunk and the trunk Status is Enabled, then check the number has an Inbound agent assigned in Agora - a number left Unassigned accepts the call and drops it.

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Inbound calls connect but the audio is one-way or fails

Check the origination URI region matches your number’s country code. A number routed to the wrong regional SBC may signal correctly while media fails.

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Next steps

Outbound Trunks

Trunk settings, recording, and webhooks

Credentials List

Create and rotate SIP credentials

Inbound Trunks

Route inbound calls to your agent

IP Whitelisting

Vobiz SIP signaling and RTP ranges