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Elastic SIP Trunking REST API Reference

Twilio Elastic SIP Trunking is a cloud-based solution that provides connectivity for IP-based communications infrastructure to connect to the PSTN. Using Elastic SIP Trunking you can make and receive phone calls to the rest of the world via any broadband internet connection.

Not an engineer? See our Elastic SIP Trunking product page or talk to our sales team.

Get Started with Twilio Elastic SIP Trunking

Saying "Ahoy, world" is only a few steps away.

Start by configuring your trunk. There you'll learn how to:

  • Use the Twilio Console to create a new trunk
  • Configure IP Access Control Lists (ACLs)
  • Manage the credentials your devices will use to authenticate to your trunk
  • Purchase a new Twilio phone number to use with your trunk

You'll also explore features like call recording, secure trunking, disaster recovery URLs, and CNAM lookup.

Get started here.

Connect your PBX or SBC

Once your trunk is ready, check out our guides for connecting your PBX or SBC to your Twilio trunk.

REST API documentation

Elastic SIP Trunking's REST API enables you to interact with Trunking resources from your server-side applications.

Base URL

All Elastic SIP Trunking URLs referenced in the documentation have the following base:

All Twilio REST APIs are served over HTTPS. To ensure data privacy, unencrypted HTTP is not supported.

You can control your connectivity into Twilio’s platform by including your specific edge location in the subdomain. This will allow you to bring Twilio’s public or private network connectivity closer to your applications for improved performance.

For instance customers with infrastructure in Australia can make use of the sydney edge location by using the base url of:


HTTP requests to the REST API are protected with HTTP Basic authentication like other REST APIs provided by Twilio. To learn more about how Twilio handles authentication, please refer to our security documentation. In short, you will use your Twilio account SID as the username and your auth token as the password for HTTP Basic authentication.

curl -G \

You can find your account SID and auth token on your dashboard.


Here are the resources you will be interacting with via the REST API:

Resource Description
Trunks An Elastic SIP Trunk that provides your IP-based communications infrastructure with connectivity to the PSTN.
CredentialLists List of Credentials associated with a Trunk to ensure the security/authenticity of your termination traffic.
IpAccessControlLists List of IP Access Control Lists associated with your Trunk to ensure the security/authenticity of your termination traffic.
OriginationURLs Origination settings of your Trunk will allow you to receive incoming traffic from the PSTN to a Twilio number, delivered to your communications infrastructure.
PhoneNumbers List of Twilio Numbers associated with your Trunk to allow you to receive incoming traffic from the PSTN to these Numbers.

More documentation

Here's more documentation to help you configure, test, and scale your trunk:

If you have questions related to pricing, check out our pricing page or you can reach out to our Sales team.

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Need some help?

We all do sometimes; code is hard. Get help now from our support team, or lean on the wisdom of the crowd by visiting Twilio's Stack Overflow Collective or browsing the Twilio tag on Stack Overflow.

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