How can I connect a soft phone with Vonage SIP trunk to make outbound calls?

Objective

Connecting a soft client with Vonage SIP trunk to make outbound calls.

Applies To

• SIP Trunk
• VoIP Phones
• Outbound Calls

Contents

• For Zoiper5
• For Retell AI

Procedure

You can connect a VoIP soft or hard phone directly to Vonage SIP trunk for outbound call, to use Vonage's SIP trunks for your VoIP phone calls, use the following credentials:

• Host: sip-us.vonage.com (AMER), or sip-eu.vonage.com (EMEA), or sip-ap.vonage.com (APAC), depending on your region.
• Username: Your Vonage API Key
• Password: Your Vonage API Secret

Application

Zoiper5 (for outbound call only)

1. Create a New SIP Trunk

If you haven’t already, create a new SIP trunk at: https://dashboard.nexmo.com/sip-trunking/

In this example, we’ve created a trunk with the domain: zoipervonagetest.

2. Create an Authentication User

Create an authentication user and password for that SIP Trunk

In this example:

• Username: UserZoiper5

• Password (user secret): (your chosen password)

3. Link a Virtual Number to the SIP Trunk

Assign a virtual number to your SIP trunk.
In this example, we assign the US number: +1 206 649 XXXX.

After this step, you should see the SIP trunk connection URL displayed depending on your regions:

• zoipervonagetest.sip-us.vonage.com (AMER)
  zoipervonagetest.sip-eu.vonage.com (EMEA)
• zoipervonagetest.sip-ap.vonage.com (APAC)

4. Configure Zoiper5

Skip the account setup wizard when launching Zoiper5. Then go to: Settings → Accounts → Add Account and configure the following:

• Domain: The SIP trunk URL shown in your configuration.
  For example, if you're using the US region:
  zoipervonagetest.sip-us.vonage.com

• Username: The virtual number linked to your SIP trunk (e.g., 1206649XXXX)

• Password: The user secret for UserZoiper5 (created in Step 2)

• Use Auth Username: Yes Auth Username: UserZoiper5 (username created in in Step 2)

Retell AI

1. Set Up a SIP Trunk in Vonage:
 
• Log in to your Vonage dashboard.
• Navigate to the SIP section and create a new SIP trunk.
• Assign a unique domain name to your trunk (e.g., testretell).
 
2. Configure Outbound Call Authentication:
 
• In the SIP trunk settings, set up authentication for outbound calls.

• Create a user key and secret. For example:
• User Key: MyUserKey
• Secret: YourSecretPassword
 
After configuring, you should see a confirmation message indicating that the setup is complete with the domain you can copy; for me it's testretell.sip-us.vonage.com

Make sure to LINK your number to the SIP trunk.
 
3. Integrate with Retell AI:
 
• Log in to your Retell AI dashboard.
• Navigate to the telephony integration settings.
• Connect to your number via SIP trunking
 
• SIP Domain: testretell.sip.vonage.com
• User Key: MyUserKey
• Secret: YourSecretPassword
• PhoneNumber: Your US phone number you own and link to the SIP trunck
• Nickname: MyUserKey