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Twilio connects your numbers to Bolna through an Elastic SIP Trunk. On the Twilio trunk, Termination carries the calls Bolna places, and Origination carries calls to your numbers into Bolna.
This page connects Twilio over a SIP trunk. To connect your Twilio account to Bolna as a telephony provider instead, see Using Twilio.

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Before you begin

  • A Twilio account and at least one Twilio phone number. On a trial account, Twilio only lets you call verified numbers.

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Set up Twilio

1

Create the trunk and set termination

In the Twilio Console, open Elastic SIP Trunking and create a trunk. On its Termination tab, enter a Termination SIP URI, for example acme.pstn.twilio.com. This is the host Bolna dials.
2

Let Twilio recognise Bolna

Under Authentication on the Termination tab, add at least one of:
  • Credential list: create one with a username and password, and save both; you enter them in Bolna. Twilio recommends credentials.
  • IP access control list: create one with Bolna’s signalling IPs 15.252.21.46 and 13.206.230.198.
If you add both, Twilio checks both.
3

Set origination

On the Origination tab, add an origination URI:Twilio sends calls over UDP. To use TCP, enter sip:trunk.bolna.ai:5060;transport=tcp. Do not use transport=tls.
4

Add your numbers to the trunk

On the trunk’s Numbers tab, add the Twilio numbers you want on Bolna.

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Create the trunk in Bolna

1

Pick Twilio

In the sidebar, under Deploy, open SIP Trunks and click Create trunk. If your account still has legacy SIP trunks, click Open new SIP trunks first. On the Provider step, pick Twilio, enter a Trunk name and the number of Channels, and enter your Termination SIP URI in Gateway we dial. Click Continue.
2

Add Twilio's IPs and credentials

On the Carrier IPs step, add every signalling range Twilio publishes. Twilio asks you to allow all of them, because a call can arrive from any region:If you created a credential list, enter its Username and Password under Carrier credentials (optional). Click Continue.
3

Add your Twilio numbers

On the Numbers step, enter each Twilio number in E.164 format, for example +14155550100, and click Add. Click Continue, check the summary and click Create trunk.
4

Turn on Dial with leading plus

Twilio rejects a called number without the leading + with 400 Bad Request. Open the trunk’s Connection tab and, under Outbound: gateways, turn on Dial with leading plus.
The caller ID on an outbound call must be a Twilio number on your account or a caller ID you verified in Twilio. For every field on these steps, see Connect your carrier.

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Assign an agent and test

  • Inbound: open the trunk’s Numbers tab and, in the Agent column, pick an agent for your Twilio number. Then call the number. See Receive inbound calls.
  • Outbound: on the agent’s Calling tab, set Telephony Provider to SIP Trunk. In the agent’s outbound call dialog, pick your Twilio number as the caller ID, enter the number to call and click Place call. See Make outbound calls.
If a call does not connect, see Troubleshooting.