SIP Trunk Setup for Voyced – 3CX

Connect your 3CX telephone system to Voyced to make and receive calls using your business telephone number.

This guide covers 3CX Version 20, including current updates. It also explains the main differences for customers using the older Version 18 interface.

What You'll Need

Before starting, make sure you have:

• Administrator access to your 3CX telephone system.

• A 3CX installation that supports third-party SIP trunks.

• At least one working 3CX user or extension.

• An active Voyced telephone number.

• Your Voyced SIP username and Service Password.

• A working internet connection.

Voyced SIP details

Replace the example credentials with your own Voyced details.

You can find your DID under Cloud PBX / IP Centrex > Phone Lines in your Voyced Hosted IPPBX. Select the wrench icon beside your number.

Your Service Password is available under My Profile > Settings.

The Service Password is different from your Voyced website login password.

Requirements Before You Begin

1. Confirm your 3CX system has internet access.

2. Check that it can connect to sip.voyced.eu using UDP port 5060.

3. Confirm your firewall allows the SIP and RTP traffic required by your 3CX installation.

4. Make sure at least one 3CX user or extension can make internal calls.

5. Check that your 3CX edition allows you to configure a generic third-party SIP trunk.

Check your firewall

For self-hosted and on-premise 3CX installations, the standard ports include:

Other 3CX services may need additional ports.

3CX includes a Firewall Checker to test your network configuration.

To run it:

1. Open your 3CX administration interface.

2. Select Dashboard.

3. Find Firewall Checker.

4. Start the test.

5. Review any reported problems.

The test can interrupt active telephone services, so run it when no calls are in progress.

Check your firewall and NAT configuration if the test fails.

Choose the correct trunk type

For a standard Voyced connection, use:

Generic VoIP Provider (Registration)

This allows 3CX to register with Voyced using your DID and Service Password.

Do not select Generic SIP Trunk (IP-Based) for this standard configuration.

Some restricted or hosted 3CX editions do not offer generic SIP trunk configuration. If the option is unavailable, check the features supported by your edition before proceeding.

SIP Trunk Setup

Step 1: Log in to 3CX

1. Open your 3CX web interface.

2. Log in with an administrator account.

3. Open the Admin section.

In 3CX Version 20, administration is available through the Web Client.

Navigate to:

Admin > Voice & Chat

Click Add Trunk.

On older 3CX Version 18 systems, open the Management Console and select SIP Trunks > Add SIP Trunk.

Step 2: Select the SIP provider

In the provider selection window:

1. Select the country associated with your telephone service.

2. Open the Provider list.

3. Select Generic VoIP Provider (Registration).

4. Confirm your selection.

This creates a registration-based SIP trunk.

If Voyced appears in your version's provider list, you may use its specific template if the supplied connection settings match your Voyced account.

For manual configuration, use the generic registration provider.

Step 3: Configure the Voyced trunk

Under General, enter:

Use your actual Voyced DID for both Main Trunk Number and Authentication ID unless your account has separate values assigned.

The Default Route determines where incoming calls go when no more specific DID destination has been assigned.

Do not enter another telephone provider's server or authentication details.

Step 4: Configure trunk options

Open the Options tab.

Check the following settings:

Keep the other advanced options at their defaults for the first connection.

If 3CX offers an automatic registrar discovery option, use sip.voyced.eu as the hostname.

Step 5: Configure audio codecs

In the Options tab, find Codec Priority.

Use the following order:

1. G.711 A-law (PCMA).

2. G.711 μ-law (PCMU).

These codecs provide broad compatibility with Voyced.

G.729 may also be used where supported by your installation and the complete call route.

For initial testing, use PCMA and PCMU.

If you experience one-way audio, the PBX Delivers Audio option may help in some network configurations. Check your firewall and NAT settings as well.

Step 6: Add your Voyced DID

Open the DID Numbers tab.

1. Click Add.

2. Enter your Voyced telephone number.

3. Save the entry.

For example:

442035001234

Use the DID format actually presented to 3CX on incoming calls.

If you have several Voyced numbers delivered through the same trunk, add the relevant DIDs.

Each DID can be assigned to a different user, ring group, queue or digital receptionist.

Step 7: Configure incoming call routing

In 3CX Version 20, incoming call routing is managed through the destination assigned to the DID.

For calls to a specific user:

1. Open Admin > Users.

2. Select the user.

3. Open General.

4. Find Assigned DID Number(s).

5. Select the appropriate Voyced DID.

6. Save.

For calls to a ring group, queue or digital receptionist:

1. Open Admin > Call Handling.

2. Select the destination.

3. Find Assigned DID Number(s).

4. Select your Voyced DID.

5. Save.

For example, you might route:

If a DID has no specific destination, 3CX uses the trunk's Default Route.

On 3CX Version 18, use Inbound Rules to assign the DID to the required destination.

Step 8: Create an outbound rule

An outbound rule tells 3CX which trunk to use when users make external calls.

In Version 20:

1. Open Admin > Outbound Rules.

2. Click Add.

3. Enter Voyced-Outbound as the rule name.

Configure:

This example routes international telephone numbers beginning with 00 through Voyced.

Setting Strip Digits to 0 ensures that 3CX does not remove the international prefix.

Leave Prepend empty so the number reaches Voyced unchanged.

Click Save.

National and local calls

If you also want national or local calls to use Voyced, create additional outbound rules that match the telephone number formats you use.

For example, you may create separate routes for:

• National telephone numbers.

• Mobile telephone numbers.

• International telephone numbers.

• Other permitted destinations.

3CX processes outbound rules according to their order.

Place your more specific rules above broader rules where appropriate.

Keep emergency call routing configured according to your location and telephone service.

Step 9: Configure voicemail access

Your Voyced voicemail access number is:

1233

If you want 3CX users to access Voyced voicemail:

1. Open Admin > Outbound Rules.

2. Add a rule named Voyced-Voicemail.

3. Set Calls to Numbers Starting with Prefix to 1233.

4. Set Calls to Numbers with a Length of to 4.

5. Select the Voyced trunk.

6. Set Strip Digits to 0.

7. Leave Prepend empty.

8. Save.

Check that this rule does not conflict with an existing 3CX feature or internal dialling code.

3CX also provides its own voicemail system.

If your organisation uses 3CX voicemail, you can continue using that instead of the Voyced voicemail service.

Step 10: Configure Caller ID

Caller ID is the telephone number shown to the person receiving your call.

By default, Voyced uses the authorised number assigned to your SIP account.

3CX allows Caller ID configuration at the trunk, user and outbound rule levels.

Use only telephone numbers authorised on your Voyced service.

If you want to display another telephone number:

1. Log in to your Voyced client area.

2. Open a sales support ticket.

3. Use the subject Outbound Caller ID adjustment.

4. Provide your Voyced DID.

5. Provide the telephone number you want displayed.

Numbers outside your Voyced account require proof of ownership and additional verification.

Voyced Internal DIDs and extension numbers must not be used as public Caller ID numbers.

Step 11: Save and check registration

Once your trunk settings are complete:

1. Click Save.

2. Return to Admin > Voice & Chat.

3. Find your Voyced SIP trunk.

4. Check its registration indicator.

A green indicator means the trunk is registered.

A red indicator means registration has failed or the trunk is unavailable.

If your Voyced trunk does not register, check the credentials, server address, transport and firewall settings before proceeding.

Test Your Connection

Once your Voyced trunk shows Registered, complete the following tests.

Test 1: Outgoing calls

1. Open the 3CX Web Client or use a connected telephone.

2. Dial an external telephone number.

3. Confirm the call connects through Voyced.

4. Check audio in both directions.

5. Verify the Caller ID displayed to the recipient.

Test 2: Incoming calls

1. Call your Voyced telephone number from another telephone.

2. Confirm 3CX receives the call.

3. Check that the DID reaches the correct user, ring group or digital receptionist.

4. Answer and check audio in both directions.

Test 3: International calls

Voyced requires international calls to use:

00 + Country Code + Telephone Number

For example:

00442035000202

Make sure 3CX passes the complete number through the Voyced trunk.

The outbound rule must not remove the leading 00.

Test 4: Voicemail

Dial:

1233

Confirm that you reach your Voyced voicemail service.

If your organisation uses 3CX voicemail, test that separately.

Test 5: Simultaneous calls

If your Voyced service supports multiple simultaneous calls, test the expected call capacity.

The available number of external calls depends on your Voyced service and the limits configured in 3CX.

Troubleshooting

The SIP trunk does not register

Check:

Do not use your Voyced website login password.

A SIP 401 authentication challenge can be part of normal registration. Repeated authentication failures indicate a problem that needs investigation.

Generic SIP provider is unavailable

Some 3CX editions or hosted configurations restrict the providers you can select.

Check whether your installation permits generic registration-based SIP trunks.

Do not select an unrelated provider template simply to bypass a restriction. The template may contain settings that do not match Voyced.

Incoming calls do not work

• Confirm the Voyced trunk is registered.

• Check that your DID is listed under DID Numbers.

• Confirm the DID is assigned to the correct destination.

• Check the trunk's Default Route.

• Review your firewall and NAT settings.

If incoming calls reach the default route instead of the intended destination, check the DID format received by 3CX.

The configured DID must match the number extracted from the incoming SIP message.

Outgoing calls do not work

• Confirm the Voyced trunk is registered.

• Check that an outbound rule matches the dialled number.

• Confirm Route 1 selects Voyced.

• Check that the calling user or department is permitted to use the rule.

• Review the outbound rule order.

• Check your Voyced call credit and destination permissions.

International calls fail

Check that:

• The dialled number begins with 00.

• The outbound rule matches prefix 00.

• Strip Digits is 0.

• Prepend is empty.

• Another outbound rule is not taking priority.

For example, 00442035000202 must reach Voyced unchanged.

Incoming calls reach the wrong destination

In Version 20, check the DID assignment under:

• Admin > Users, for individual users.

• Admin > Call Handling, for ring groups, queues and digital receptionists.

Check that the same number is not incorrectly assigned elsewhere.

Also review the trunk's Default Route.

No audio or one-way audio

• Check the 3CX firewall configuration.

• Confirm UDP RTP ports 9000–10999 are available where required.

• Run the 3CX Firewall Checker.

• Verify the public IP and NAT settings.

• Check your telephone or Web Client audio devices.

• Start with PCMA and PCMU codecs.

If your router has SIP ALG enabled and it interferes with SIP signalling, disable it.

Incorrect Caller ID

Check the outbound Caller ID settings on the user, outbound rule and SIP trunk.

Only use numbers authorised on your Voyced account.

If another number is required, contact Voyced Support.

Voicemail does not work

• Confirm the Voyced trunk is registered.

• Check your outbound rule for 1233.

• Make sure another internal code does not intercept it.

• Verify that the calling user can use the route.

Check the 3CX Event Log

For registration and call failures:

1. Open Admin > Event Log.

2. Find entries relating to the Voyced trunk or failed call.

3. Review the SIP response or error.

4. Check the registration and routing details.

Common SIP responses include:

When contacting Voyced Support, provide the date, time, destination number and result of the failed call.

Do not share your Service Password.

Final Tips

• Use sip.voyced.eu as your primary SIP server.

• Select Generic VoIP Provider (Registration) for a standard Voyced account.

• Use your Voyced DID as the authentication username.

• Use UDP port 5060.

• Start with PCMA and PCMU audio codecs.

• Configure your main number and additional DIDs correctly.

• In 3CX Version 20, assign incoming DIDs through Users or Call Handling.

• Create outbound rules that select the Voyced trunk.

• Use prefix 00 for international outbound rules.

• Keep Strip Digits at 0 so the international prefix remains intact.

• Use only authorised outbound Caller ID numbers.

• Check your firewall and NAT configuration if calls have registration or audio problems.

• Test incoming and outgoing calls after changing trunk or routing settings.

Once registration, incoming calls, outgoing calls and audio have been tested successfully, your 3CX telephone system is ready to use with Voyced.

Last updated: 27/10/2026

© Voyced
All information provided is copyrighted and purely informative in nature. It is maintained by Voyced with the greatest of care using reliable sources only.
Given the fast evolution of the telecom sector, Voyced does not offer any guarantee about the accuracy and completeness of the information offered. 
We explicitly do not give anyone permission to use this information in any other way than to inform themselves about what (legal) requirements there may be and they need to comply with when registering Services and/or DIDs with Voyced.