SIP outbound trunk | LiveKit Docs

To provision an outbound trunk with the SIP Service, use the CreateSIPOutboundTrunk API. It returns an SIPOutboundTrunkInfo object that describes the created SIP trunk. You can query these parameters any time using the ListSIPOutboundTrunk API.

Restricting calls to a region

To originate calls from the same region as the destination phone number, set the destination_country parameter for an outbound trunk. This applies region pinning to all calls made through the trunk. When destination_country is enabled, outbound calls are routed based on location:

For countries that LiveKit operates data centers in, calls originate from a server within the country.
For other countries, calls originate from a server that is closest to that country.

In the unlikely event that the preferred region is non-operational or offline, calls originate from another region nearby. For a full list of supported regions, see Available regions.

The destination_country parameter accepts a two-letter country code. To learn more, see CreateSIPOutboundTrunk.

Create an outbound trunk

The following creates a SIP outbound trunk with username and password authentication. It makes outbound calls from number +15105550100.

Create a file named outbound-trunk.json using your phone number, trunk domain name, and username and password:

{
  "trunk": {
    "name": "My outbound trunk",
    "address": "<my-trunk>.pstn.twilio.com",
    "numbers": ["+15105550100"],
    "authUsername": "<username>",
    "authPassword": "<password>"
  }
}

{
  "trunk": {
    "name": "My outbound trunk",
    "address": "sip.telnyx.com",
    "numbers": ["+15105550100"],
    "authUsername": "<username>",
    "authPassword": "<password>"
  }
}

Note

Use a regional SIP Signaling Address from Telnyx SIP Signaling Addresses for the address field. This example config uses the US SIP proxy, sip.telnyx.com.

Create the outbound trunk using the CLI:
```
lk sip outbound create outbound-trunk.json
```
The output of the command returns the trunk ID. Copy it for the next step:
```
SIPTrunkID: <your-trunk-id>
```

import { SipClient } from 'livekit-server-sdk';

const sipClient = new SipClient(process.env.LIVEKIT_URL,
                                process.env.LIVEKIT_API_KEY,
                                process.env.LIVEKIT_API_SECRET);

// SIP address is the hostname or IP the SIP INVITE is sent to.
// Address format for Twilio: <trunk-name>.pstn.twilio.com
// Address format for Telnyx: sip.telnyx.com
const address = 'sip.telnyx.com';

// An array of one or more provider phone numbers associated with the trunk.
const numbers = ['+12135550100'];

// Trunk options
const trunkOptions = {
  auth_username: '<username>',
  auth_password: '<password>'
};

const trunk = sipClient.createSipOutboundTrunk(
  'My trunk',
  address,
  numbers,
  trunkOptions
);

import asyncio

from livekit import api
from livekit.protocol.sip import CreateSIPOutboundTrunkRequest, SIPOutboundTrunkInfo

async def main():
  lkapi = api.LiveKitAPI()

  trunk = SIPOutboundTrunkInfo(
    name = "My trunk",
    address = "sip.telnyx.com",
    numbers = ['+12135550100'],
    auth_username = "<username>",
    auth_password = "<password>"
  )

  request = CreateSIPOutboundTrunkRequest(
    trunk = trunk
  )

  trunk = await lkapi.sip.create_sip_outbound_trunk(request)

  print(f"Successfully created {trunk}")

  await lkapi.aclose()

asyncio.run(main())

require 'livekit'

name = "My trunk"
address = "sip.telnyx.com"
numbers = ["+12135550100"]
auth_username = "<username>"
auth_password = "<password>"

sip_service = LiveKit::SIPServiceClient.new(
  ENV['LIVEKIT_URL'],
  api_key: ENV['LIVEKIT_API_KEY'],
  api_secret: ENV['LIVEKIT_API_SECRET']
)

resp = sip_service.create_sip_outbound_trunk(
    name,
    address,
    numbers,
    auth_username: auth_username,
    auth_password: auth_password
)

puts resp.data

package main

import (
  "context"
  "fmt"
  "os"

  lksdk "github.com/livekit/server-sdk-go/v2"
  "github.com/livekit/protocol/livekit"
)

func main() {
  trunkName := "My trunk"
  address := "sip.telnyx.com"
  numbers := []string{"+16265550100"}

  trunkInfo := &livekit.SIPOutboundTrunkInfo{
    Name: trunkName,
    Address: address,
    Numbers: numbers,
  }

  // Create a request
  request := &livekit.CreateSIPOutboundTrunkRequest{
    Trunk: trunkInfo,
  }

  sipClient := lksdk.NewSIPClient(os.Getenv("LIVEKIT_URL"),
                                  os.Getenv("LIVEKIT_API_KEY"),
                                  os.Getenv("LIVEKIT_API_SECRET"))
  
  // Create trunk
  trunk, err := sipClient.CreateSIPOutboundTrunk(context.Background(), request)

  if (err != nil) {
    fmt.Println(err)
  } else {
    fmt.Println(trunk)
  }
}

Sign in to the LiveKit Cloud dashboard.
Select Telephony → Configuration.
Select Create new → Trunk.
Select the JSON editor tab.
Note
You can also use the Trunk details tab to create a trunk. However, the JSON editor allows you to configure all available parameters.
Select Outbound for Trunk direction.

Copy and paste the following text into the editor:

{
  "name": "My outbound trunk",
  "address": "sip.telnyx.com",
  "numbers": [
    "+12135550100"
  ],
  "authUsername": "test_username",
  "authPassword": "test_password"
}

Select Create.

Configuring an outbound trunk for any phone number

The numbers parameter for outbound trunks is a required field. However, you can set the parameter to any string (for example, *) to use the outbound trunk for calls from any number. This is useful if you want to use the same outbound trunk for all calls or if you want to use a different phone number for each call.

Instead of setting the number on the trunk, you can set the phone number to call from using the sip_number parameter for the CreateSIPParticipant API.

The following example creates an outbound trunk that allows calling from any number, then initiates a call using the outbound trunk.

Create an outbound trunk using the CLI.

Create a file named outbound-trunk.json and copy and paste the following content:

{
    "trunk": {
      "name": "My outbound trunk",
      "address": "<my-trunk>.pstn.twilio.com",
      "numbers": ["*"],
      "auth_username": "<username>",
      "auth_password": "<password>"
    }
  }

Create the outbound trunk using the CLI:

lk sip outbound create outbound-trunk.json

Initiate a call from the number +15105550100 using the CLI. This number is the phone number configured with your SIP trunk provider. Use the <trunk-id> from the output of the previous step.
Create a file named participant.json and copy and paste the following content:
```
{
  "sip_number": "+15105550100",
  "sip_trunk_id": "<trunk-id>",
  "sip_call_to": "+12135550100",
  "room_name": "open-room",
  "participant_identity": "sip-test",
  "participant_name": "Test call participant",
  "wait_until_answered": true
}
```
Important
If you're using Telnyx, the leading + in the phone number assumes the Destination Number Format is set to +E.164 for your number.
Initiate the call using the CLI:
```
lk sip participant create participant.json
```
After you run the command, a call from the number +15105550100 to +12135550100 is initiated. Output from the command returns when the call is answered.

List outbound trunks

Use the ListSIPOutboundTrunk API to list all outbound trunks and trunk parameters.

lk sip outbound list

import { SipClient } from 'livekit-server-sdk';

const sipClient = new SipClient(process.env.LIVEKIT_URL,
                                process.env.LIVEKIT_API_KEY,
                                process.env.LIVEKIT_API_SECRET);

const rules = await sipClient.listSipOutboundTrunk();

console.log(rules);

import asyncio

from livekit import api
from livekit.protocol.sip import ListSIPOutboundTrunkRequest

async def main():
  livekit_api = api.LiveKitAPI()

  rules = await livekit_api.sip.list_sip_outbound_trunk(
    ListSIPOutboundTrunkRequest()
  )
  print(f"{rules}")

  await livekit_api.aclose()

asyncio.run(main())

require 'livekit'

sip_service = LiveKit::SIPServiceClient.new(
  ENV['LIVEKIT_URL'],
  api_key: ENV['LIVEKIT_API_KEY'],
  api_secret: ENV['LIVEKIT_API_SECRET']
)

resp = sip_service.list_sip_outbound_trunk()

puts resp.data

package main

import (
  "context"
  "fmt"
  "os"

  lksdk "github.com/livekit/server-sdk-go/v2"
  "github.com/livekit/protocol/livekit"
)

func main() {

  sipClient := lksdk.NewSIPClient(os.Getenv("LIVEKIT_URL"),
                                  os.Getenv("LIVEKIT_API_KEY"),
                                  os.Getenv("LIVEKIT_API_SECRET"))

  // List dispatch rules
  trunks, err := sipClient.ListSIPOutboundTrunk(
    context.Background(), &livekit.ListSIPOutboundTrunkRequest{})

  if err != nil {
    fmt.Println(err)
  } else {
    fmt.Println(trunks)
  }
}

Sign in to the LiveKit Cloud dashboard.
Select Telephony → Configuration.
The Outbound section lists all outbound trunks.

Update an outbound trunk

The UpdateSIPOutboundTrunk API allows you to update specific fields of an outbound trunk or replace an outbound trunk with a new one.

Update specific fields of an outbound trunk

The UpdateSIPOutboundTrunkFields API allows you to update specific fields of an outbound trunk without affecting other fields.

Create a file named outbound-trunk.json with the fields you want to update. The following example updates the name and phone numbers for the trunk:
```
{
   "name": "My updated outbound trunk",
   "address": "<my-trunk>.pstn.twilio.com",
   "numbers": ["+15105550100"]
}
```
```
{
   "name": "My updated outbound trunk",
   "address": "sip.telnyx.com",
   "numbers": ["+15105550100"]
}
```
Note
Use a regional SIP Signaling Address from Telnyx SIP Signaling Addresses for the address field. This example config uses the US SIP proxy, sip.telnyx.com.

Update the outbound trunk using the CLI:

lk sip outbound update --id <sip-trunk-id> outbound-trunk.json

The output of the command returns the trunk ID:

SIPTrunkID: <your-trunk-id>

import { SipClient } from 'livekit-server-sdk';

const sipClient = new SipClient(process.env.LIVEKIT_URL,
                                process.env.LIVEKIT_API_KEY,
                                process.env.LIVEKIT_API_SECRET);

/**
 * Update fields of an outbound trunk.
 * @param {string} trunkId The ID of the trunk to update.
 * @returns {Object} The result of the update operation.
 */
async function updateTrunk(trunkId) {

  const updatedTrunkFields = {
    name: 'My updated trunk',
    address: 'my-trunk.pstn.twilio.com',
  }
  
  const trunk = await sipClient.updateSipOutboundTrunkFields (
    trunkId,
    updatedTrunkFields,
  );

  return trunk;
}

updateTrunk('<outbound-trunk-id>');

import asyncio

from livekit import api


async def main():
  lkapi = api.LiveKitAPI()

  trunk = await lkapi.sip.update_sip_outbound_trunk_fields(
    trunk_id = "<sip-trunk-id>",
    name = "My updated outbound trunk",
    address = "sip.telnyx.com",
    numbers = ['+15105550100']
  )

  print(f"Successfully updated {trunk}")

  await lkapi.aclose()

asyncio.run(main())

The Ruby SDK doesn't yet support updating outbound trunks.

package main

import (
  "context"
  "fmt"
  "os"

  lksdk "github.com/livekit/server-sdk-go/v2"
  "github.com/livekit/protocol/livekit"
)

func main() {
  trunkName := "My updated outbound trunk"
  numbers := &livekit.ListUpdate{Set: []string{"+16265550100"}}
  transport := livekit.SIPTransport_SIP_TRANSPORT_UDP

  trunkId := "<sip-trunk-id>"

  trunkInfo := &livekit.SIPOutboundTrunkUpdate{
    Name: &trunkName,
    Numbers: numbers,
    Transport: &transport,
  }

  // Create a request
  request := &livekit.UpdateSIPOutboundTrunkRequest{
    SipTrunkId: trunkId,
    Action: &livekit.UpdateSIPOutboundTrunkRequest_Update{
      Update: trunkInfo,
    },  
  }

  sipClient := lksdk.NewSIPClient(os.Getenv("LIVEKIT_URL"),
                                  os.Getenv("LIVEKIT_API_KEY"),
                                  os.Getenv("LIVEKIT_API_SECRET"))
  
  // Update trunk
  trunk, err := sipClient.UpdateSIPOutboundTrunk(context.Background(), request)

  if err != nil {
    fmt.Println(err)
  } else {
    fmt.Println(trunk)
  }
}
~

Update and replace functions are the same in the LiveKit Cloud dashboard. For an example, see the replace an outbound trunk section.

Replace an outbound trunk

The UpdateSIPOutboundTrunk API allows you to replace an existing outbound trunk with a new one using the same trunk ID.

The CLI doesn't support replacing outbound trunks.

import { SipClient } from 'livekit-server-sdk';

const sipClient = new SipClient(process.env.LIVEKIT_URL,
                                process.env.LIVEKIT_API_KEY,
                                process.env.LIVEKIT_API_SECRET);

async function replaceTrunk(trunkId) {
  // Replace an inbound trunk entirely.
  const trunk = {
    name: "My replaced trunk",
    address: "sip.telnyx.com",
    numbers: ['+17025550100'], 
    metadata: "{\"is_internal\": true}",
    authUsername: '<updated-username>',
    authPassword: '<updated-password>',
  };

  const updatedTrunk = await sipClient.updateSipOutboundTrunk(
    trunkId,
    trunk
  );

  return updatedTrunk;
}

replaceTrunk('<outbound-trunk-id>');

To replace a trunk, edit the previous example by adding the following import, trunk, and call the update_sip_outbound_trunk function:

from livekit.protocol.sip import SIPOutboundTrunkInfo, SIPTransport

  trunk = SIPOutboundTrunkInfo(
      address = "sip.telnyx.com",
      numbers = ['+15105550100'],
      name = "My replaced outbound trunk",
      transport = SIPTransport.SIP_TRANSPORT_AUTO,
      auth_username = "<username>",
      auth_password = "<password>",
  )

  trunk = await lkapi.sip.update_sip_outbound_trunk(
    trunkId,
    trunk
  )

The Ruby SDK doesn't yet support updating outbound trunks.

To replace a trunk, use the previous example with the following trunkInfo and request values:

// Create a SIPOutboundTrunkInfo object
  trunkInfo := &livekit.SIPOutboundTrunkInfo{
    Name: "My replaced outbound trunk",
    Address: "sip.telnyx.com",
    Numbers: []string{"+16265550100"},
    Transport: livekit.SIPTransport_SIP_TRANSPORT_AUTO,
    AuthUsername: "<username>",
    AuthPassword: "<password>",
  }

  // Create a request
  request := &livekit.UpdateSIPOutboundTrunkRequest{
    SipTrunkId: trunkId,
    Action: &livekit.UpdateSIPOutboundTrunkRequest_Replace{
      Replace: trunkInfo,
    },  
  }

Sign in to the Telephony → Configuration page.
Navigate to the Outbound section.
Find the outbound trunk you want to replace → select the more (⋮) menu → select Configure trunk.

Copy and paste the following text into the editor:

{
  "name": "My replaced trunk",
  "address": "sip.telnyx.com",
  "numbers": [
    "+17025550100"
  ],
  "metadata": "{\"is_internal\": true}",
  "authUsername": "<updated-username>",
  "authPassword": "<updated-password>"
}

Select Update.

IP address range for LiveKit Cloud SIP

LiveKit Cloud nodes do not have a static IP address range, thus there's no way currently to use IP range for outbound authentication.

Thus, prefer setting user/password authentication on SIP trunk Provider.

If it's unavailable, or IP range is required in addition to user/password, set range(s) that include all IPs: e.g. 0.0.0.0/0 or 0.0.0.0/1+128.0.0.0/1.