SIP Trunk Setup for 2600Hz KAZOO

Use Voyced as an external SIP provider

This guide explains how to configure Voyced as an external telephone provider in 2600Hz KAZOO.

KAZOO supports external SIP carriers through its Resources system. It can send outgoing calls to a carrier using SIP username and password authentication.

There is one important limitation.

KAZOO's standard carrier Resources do not register with external SIP providers.

The standard Voyced connection uses SIP registration for incoming call delivery. As a result, KAZOO's normal carrier configuration does not support a complete two-way connection with Voyced.

You can configure the outbound connection as described below. Whether calls succeed depends on the authentication requirements of your Voyced account.

This manual covers KAZOO's Resources API and the Monster UI Carrier application.

What You'll Need

Before you begin, make sure you have:

• Administrator access to your KAZOO installation

• A working KAZOO account

• Access to the Carrier application or Resources API

• At least one configured user and SIP telephone

• Permission to create carrier resources

• An active Voyced telephone number

Your Voyced SIP details:

Replace the example username and password with your actual Voyced service details.

Requirements Before You Begin

Your KAZOO installation must have:

• A working internet connection

• Correct DNS resolution

• A functioning SIP signalling service

• A configured internal telephone or softphone

• Access to external carrier routing

• Sufficient call capacity

Recommended audio settings:

The KAZOO carrier documentation specifies 20 ms RTP packet timing for compatible audio handling.

Voyced expects full international telephone numbers without a leading +.

Example:

442012345678

Important: Supported Connection Method

KAZOO supports two different types of SIP authentication.

Device registration

Telephones and SIP endpoints can register with KAZOO using their own credentials.

Outbound carrier authentication

KAZOO sends an outgoing SIP INVITE to an external provider and can respond to a SIP authentication challenge.

These are different operations.

The standard KAZOO carrier Resource does not send SIP REGISTER requests to Voyced.

For this reason:

• Outbound calling can be configured and tested.

• Outbound calling is not guaranteed until authentication succeeds.

• Direct inbound delivery through Voyced's standard registration method is not supported by this configuration.

Permitted Calling Traffic

Voyced provides retail-quality services for normal business telephone conversations.

Automated bulk calling, predictive dialling and short-burst traffic are not permitted.

If you use KAZOO with contact centre software, configure it for normal incoming calls and individually initiated outbound conversations.

SIP Trunk Setup Steps

1. Log in to KAZOO

If your installation includes Monster UI:

1. Open your KAZOO administration interface.

2. Log in using an administrator account.

3. Open the Carrier application.

4. Select Service Providers.

5. Select Set Locally.

The Set Locally option configures a carrier for the current KAZOO account.

If you manage a service provider's entire KAZOO installation, you may also have access to system-wide carrier resources.

For a normal business account using Voyced, create an account-level resource.

If your installation does not provide the Carrier application, use the Resources API described later in this guide.

2. Create the Voyced Carrier

In the Carrier application:

1. Click the + button to add a provider.

2. Select Other as the provider template.

3. Enter a name for the new carrier.

4. Configure the SIP server.

Enter:

The available fields depend on the Carrier application installed with your KAZOO system.

The server hostname must be:

sip.voyced.eu

The username must be your Voyced SIP account number.

The password must be your Voyced SIP service password.

Select UDP transport where the interface provides a transport setting.

3. Configure the Carrier Gateway

KAZOO uses a Gateway to describe the SIP destination for an external carrier.

Open the carrier's advanced gateway configuration.

Use:

The realm identifies the SIP authentication domain.

For the initial configuration, use sip.voyced.eu.

If Voyced returns a different authentication realm in a SIP challenge, use the realm supplied by that response.

KAZOO's gateway configuration supports SIP Digest authentication for outgoing calls.

It does not establish SIP registration.

4. Configure International Number Formatting

KAZOO commonly normalises telephone numbers into an internal international format containing a leading +.

Voyced expects the outgoing destination without this character.

For example:

KAZOO provides a gateway option specifically for this purpose.

Set:

"invite_format": "strip_plus"

The strip_plus setting removes the leading + from the outgoing destination number.

This option is available through KAZOO's carrier resource configuration.

If your Carrier application does not expose this setting, use the Resources API.

Do not select an outgoing number format that adds national dialling prefixes or changes the country code.

5. Configure Outbound Caller ID

Your outgoing calls should present an authorised telephone number.

In your KAZOO account's caller ID settings, configure:

KAZOO stores caller ID details at account, user and sometimes device level.

For the first test, use your registered Voyced telephone number.

KAZOO can also format the SIP From header through its carrier configuration.

For the Voyced gateway, the relevant options are:

{
  "format_from_uri": true,
  "from_uri_realm": "sip.voyced.eu"
}

This configures the SIP From domain.

The outgoing caller ID number must also be sent without an unwanted leading +.

The API example later in this guide includes a formatter for this.

Use only telephone numbers authorised for presentation through your Voyced service.

6. Configure Audio Codecs

Open the carrier's Advanced Settings.

Find Audio Settings.

Select:

1. PCMA

2. PCMU

Move both codecs into the selected codec list.

Recommended configuration:

Set the RTP packet time to 20 ms where your installation provides this option.

Keep standard RFC2833/RFC4733 DTMF signalling.

Save the audio settings.

7. Configure Outbound Calling Rules

KAZOO uses routing rules to determine which carrier handles outgoing calls.

In the Carrier application:

1. Open your Voyced provider.

2. Locate Rules.

3. Click + to add a rule.

4. Select the destinations you want to send through Voyced.

For international calling, select the International rule if it matches your required destinations.

KAZOO also supports custom regular expressions.

A suitable starting expression for international numbers is:

^\+?[1-9][0-9]{7,14}$

This matches international numbers containing 8 to 15 digits, with an optional leading +.

For example:

+442012345678

and:

442012345678

The strip_plus gateway setting ensures the final number sent to Voyced does not contain the leading +.

The example expression is intended for initial testing. Adjust your routing rules to permit only the destinations your organisation needs.

Do not use the unrestricted Unknown rule for normal production routing.

The Unknown rule may match numbers that should be handled by another part of your dial plan.

Enable the completed routing rule.

8. Configure Carrier Calling Priority

If you use several external carriers, KAZOO can select them according to calling priorities.

Open:

Carrier → Calling Priorities

Select how your providers should be used.

For example:

If Voyced is your only intended provider for normal outgoing calls, select it for the appropriate destination categories.

Save the changes.

Do not change existing emergency or special-service routing without confirming the new route supports those services.

9. Configure the Outbound Callflow

KAZOO uses Callflows to process outgoing calls.

If the account already has a working outbound Callflow using local carrier resources, retain it.

Otherwise, create one through the Callflows application.

The documented KAZOO method uses a special number:

no_match

This catches dialled numbers that have not matched another Callflow.

The outbound action uses:

{
  "module": "resources",
  "data": {
    "use_local_resources": true
  }
}

The setting:

"use_local_resources": true

tells KAZOO to use carrier resources configured for the current account.

The Voyced resource will only be selected when its routing rules match the dialled number.

If your account already uses no_match for other services, review the existing Callflow before changing it.

Do not create a conflicting second outbound Callflow for the same special number.

10. Alternative: Configure Voyced Through the Resources API

KAZOO provides a REST API for creating carrier resources.

This method is useful when your installation does not expose all the required gateway settings in its administration interface.

You will need:

• Your KAZOO API address

• An administrator authentication token

• Your KAZOO account ID

• Permission to manage account resources

The following configuration is designed for an account-level outbound carrier.

Create a file named:

voyced-resource.json

Enter:

{
  "data": {
    "name": "Voyced Outbound",
    "enabled": true,
    "rules": [
      "^\\+?[1-9][0-9]{7,14}$"
    ],
    "gateways": [
      {
        "server": "sip.voyced.eu",
        "port": 5060,
        "realm": "sip.voyced.eu",
        "username": "Your-Voyced-DID",
        "password": "YourServicePassword",
        "invite_format": "strip_plus",
        "codecs": [
          "PCMA",
          "PCMU"
        ],
        "format_from_uri": true,
        "from_uri_realm": "sip.voyced.eu",
        "enabled": true
      }
    ],
    "formatters": {
      "from": [
        {
          "regex": "^\\+?([1-9][0-9]{7,14})$",
          "direction": "outbound"
        }
      ]
    }
  }
}

Replace the Voyced username and password placeholders with your actual account details.

This configuration:

• Creates an outbound carrier named Voyced Outbound.

• Sends SIP calls to sip.voyced.eu.

• Uses UDP destination port 5060.

• Provides credentials for outbound SIP authentication.

• Uses PCMA and PCMU.

• Removes the leading + from the destination number.

• Formats the outgoing SIP From number without a leading +.

• Selects the carrier only for numbers matching the routing rule.

It does not send SIP REGISTER requests.

Create the Resource

From a computer or administration server with access to your KAZOO API, run:

curl -X PUT \
  "https://YOUR_KAZOO_API/v2/accounts/YOUR_ACCOUNT_ID/resources" \
  -H "X-Auth-Token: YOUR_AUTH_TOKEN" \
  -H "Content-Type: application/json" \
  --data-binary @voyced-resource.json

Replace:

• YOUR_KAZOO_API with your API hostname

• YOUR_ACCOUNT_ID with your account ID

• YOUR_AUTH_TOKEN with your administrator authentication token

Use your KAZOO API's actual HTTPS address.

KAZOO returns the created resource details.

Keep the resource ID for future changes.

11. Verify the Carrier Resource

To retrieve your account's carrier resources, use:

curl -X GET \
  "https://YOUR_KAZOO_API/v2/accounts/YOUR_ACCOUNT_ID/resources" \
  -H "X-Auth-Token: YOUR_AUTH_TOKEN"

Find:

Voyced Outbound

Check that the gateway contains:

You should also confirm that the relevant outbound routing rule is present.

The resource appearing in KAZOO confirms its configuration has been saved.

It does not confirm successful SIP registration or outbound call compatibility.

12. Configure the Outbound Callflow Through the API

If you do not already have an outbound Callflow, you can create one through the API.

Create a file named:

voyced-outcall.json

Enter:

{
  "data": {
    "name": "Outbound Calls",
    "numbers": [
      "no_match"
    ],
    "flow": {
      "module": "resources",
      "data": {
        "use_local_resources": true
      }
    }
  }
}

This Callflow uses the account's configured carrier resources when another Callflow does not match the dialled number.

Before creating it, check whether your account already has a no_match Callflow.

If one exists, update its routing carefully instead of creating a duplicate.

To create the Callflow:

curl -X PUT \
  "https://YOUR_KAZOO_API/v2/accounts/YOUR_ACCOUNT_ID/callflows" \
  -H "X-Auth-Token: YOUR_AUTH_TOKEN" \
  -H "Content-Type: application/json" \
  --data-binary @voyced-outcall.json

Replace the API address, account ID and authentication token.

After saving, the outbound Callflow should be available to the account.

13. Configure Simultaneous Call Capacity

KAZOO supports limits for simultaneous calls.

The available settings may include:

• Inbound call limits

• Outbound call limits

• Two-way call limits

• Account call limits

Configure the outbound capacity according to your Voyced service.

For example:

These values are examples only.

If your KAZOO installation already has account-level call limits, review them before changing anything.

The number of available extensions does not determine how many simultaneous external calls your Voyced account supports.

14. Understand the Inbound Calling Limitation

The standard KAZOO carrier Resource is designed to route outgoing calls to external SIP providers.

It does not register with Voyced.

The normal Voyced inbound connection requires the telephone system to register using:

A standard KAZOO Resource has no equivalent external SIP registration function.

KAZOO normally receives carrier calls when the external provider sends SIP INVITE requests directly to its signalling infrastructure.

Without the required registration, Voyced cannot establish the normal registered contact for inbound call delivery.

Creating an inbound number or Callflow in KAZOO does not resolve this limitation.

Therefore, direct inbound calling through the standard Voyced SIP registration method is not supported by this configuration.

15. Understand KAZOO's Internal Number Handling

KAZOO provides number management and incoming Callflows.

These features can assign telephone numbers to users, ring groups and other destinations.

For example, KAZOO can associate:

+442012345678

with a reception Callflow.

This internal number assignment does not cause an external carrier to deliver calls to KAZOO.

Incoming SIP delivery must already be established.

For the standard Voyced connection, the missing external SIP registration remains the limiting factor.

16. Configure Firewall and RTP

For outbound calling, your KAZOO installation must be able to reach:

sip.voyced.eu

Recommended settings:

KAZOO installations commonly use Kamailio for SIP signalling and FreeSWITCH for call processing and RTP.

The actual signalling addresses and RTP port ranges depend on your deployment.

Confirm that the required outbound SIP and RTP traffic can pass through your firewall.

If your media servers operate behind NAT, check their public media addresses and network configuration.

Testing Your Setup

Outbound Test

1. Confirm the Voyced carrier resource is enabled.

2. Confirm its routing rule is active.

3. Confirm the outgoing Callflow can access local resources.

4. Use a registered KAZOO telephone.

5. Dial an authorised international destination.

6. Place a test call.

Example destination:

442012345678

Check:

• KAZOO selects the Voyced Resource.

• The SIP INVITE reaches sip.voyced.eu.

• The destination number has no leading +.

• The SIP authentication succeeds, if challenged.

• The destination telephone rings.

• Two-way audio works.

• The correct caller ID appears.

Expected SIP Authentication

If Voyced challenges an outgoing call, the SIP exchange may include:

INVITE
401 Unauthorized or 407 Proxy Authentication Required
INVITE with authentication
200 OK

An initial authentication challenge is normal.

If subsequent authentication succeeds but the call is rejected because the account has not registered, the connection cannot be completed through KAZOO's normal carrier Resource.

Inbound Test

The standard KAZOO carrier configuration does not register with Voyced.

Incoming calls cannot be assumed to reach KAZOO through this connection.

A successful outgoing call does not establish inbound compatibility.

Troubleshooting

Outbound Calls Do Not Reach Voyced

Check:

• Carrier resource is enabled.

• Server is sip.voyced.eu.

• Port is 5060.

• The outgoing number matches a routing rule.

• The correct carrier is selected.

• The outbound Callflow uses local resources where appropriate.

• DNS resolution works.

If your installation uses several carriers, check the calling priorities.

401 or 407 Error

These responses indicate SIP authentication is required.

An initial challenge is normal.

If the call fails after authentication is attempted, check:

• SIP username

• Service password

• Authentication realm

• Whether KAZOO sends a second authenticated INVITE

KAZOO's outbound authentication does not perform SIP registration.

403 Error

Check:

• Account status

• SIP authentication

• Caller ID authorisation

• Calling permissions

• Whether the connection requires prior SIP registration

404 Error

Check:

• Destination telephone number

• Resource routing rules

• SIP Request-URI

• International number formatting

• Which system returned the response

Confirm the destination number is sent without a leading +.

Outgoing Number Contains a Leading +

Check the gateway's:

"invite_format": "strip_plus"

This setting should remove the leading + from the destination number.

If the problem remains, inspect the outgoing SIP Request-URI and any other number-formatting rules applied by KAZOO.

Incorrect Outbound Caller ID

Check:

• Account external caller ID

• User caller ID

• Gateway From URI formatting

• Resource formatters

• Authorised telephone numbers

If KAZOO presents a number beginning with +, review the outbound from formatter.

No Outgoing Route Is Found

Check:

• Carrier routing rules

• Calling priorities

• Existing no_match Callflow

• Account resource selection

• Destination number format

KAZOO must match the dialled number to an eligible resource before it can send the call.

Outbound Calls Require Prior Registration

KAZOO's standard carrier Resources do not register with external providers.

Providing the correct SIP username and password does not create a registered SIP contact.

If Voyced requires prior registration for your account, the standard direct outbound configuration is not compatible.

Incoming Calls Do Not Arrive

KAZOO's normal external carrier configuration does not send SIP REGISTER requests to Voyced.

An incoming Callflow alone cannot enable standard registration-based call delivery.

This is a connection-method limitation, not an incoming number assignment problem.

One-Way Audio

Check:

• RTP port configuration

• Firewall settings

• NAT handling

• Media server addresses

• Codec negotiation

• RTP packet time

KAZOO's carrier guidance specifies 20 ms RTP packet timing.

Carrier Appears Enabled but Calls Fail

An enabled KAZOO Resource confirms that KAZOO may select it for routing.

It does not confirm that the external provider has accepted a call.

Test:

1. Outbound routing

2. SIP authentication

3. Number formatting

4. Caller ID

5. RTP audio

Reviewing SIP Logs

For a self-managed KAZOO installation, use your existing SIP tracing tools to inspect outgoing calls.

Depending on your deployment, these may include Kamailio signalling logs, FreeSWITCH logs or SIP packet capture tools.

For the failed call, inspect:

• SIP INVITE

• Request-URI

• From

• To

• Authorization

• SIP response code

• SDP media details

Check the number and authentication response before changing the configuration.

Final Tips

• Keep the SIP server set to sip.voyced.eu.

• Use your Voyced telephone number as the outbound SIP authentication username.

• Use your Voyced service password for authentication.

• Configure Voyced as an account-level Carrier Resource where appropriate.

• Use the strip_plus gateway format for outgoing numbers.

• Use PCMA and PCMU for audio compatibility.

• Keep RTP packet timing at 20 ms.

• Restrict the carrier to the outgoing destinations your organisation needs.

• Use a permitted external caller ID.

• Check the existing outbound Callflow before adding another.

• Use Voyced only for retail and conversational calling traffic.

• Test outbound SIP authentication before relying on the connection.

Compatibility: KAZOO supports authenticated outgoing SIP requests, but its standard carrier Resources do not support SIP REGISTER to external providers.

For that reason, a complete direct inbound and outbound connection using Voyced's normal registration-based SIP service is not supported through KAZOO's standard carrier configuration. Outbound calling also requires a successful compatibility test.

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.