Connect tools & data

Connect a VoIP provider

Bring numbers you already own: guided Telnyx setup, direct Twilio/Telnyx credentials, or any SIP trunk via manual configuration.

Production traffic should run on numbers you own through your own VoIP provider. The dashboard's Connections → VoIP page (/dashboard/voip-connections) connects your provider account; once connected, you import numbers that support inbound and outbound calling.

Click New connection and pick one of three routes:

Telnyx — guided setup (recommended)#

Never used a VoIP provider before? The guided flow walks you through the whole thing:

1. Create the account

   Click Open Telnyx Signup, create your account, and check "I've created my account."

2. Get an API key

   Click Open API Keys Page, generate a key, and paste it into API Key (v2). Optionally name the connection.

3. Connect & Test

   Click Connect & Test — ThunderPhone verifies the credentials and provisions what it needs on the Telnyx side before saving.

Connect an existing account#

Already use a provider? Pick it and paste your credentials:

Manual SIP configuration#

Any SIP trunk works — including DIDWW, SignalWire, Vonage, or a PBX you run yourself. Enter the connection name, SIP domain / URI, optional username and password, port, and transport; Advanced Settings adds media encryption (SRTP) and the Allowed Source IPs list (recommended). ThunderPhone turns those settings into a dedicated trunk pair on its SIP edge: outbound calls from the connection's numbers are placed to your SIP domain with your credentials, and inbound calls to those numbers are accepted only from the allowed source IPs when you set them. Two buttons do the heavy lifting:

• Generate AI Setup Guide — writes provider-specific instructions for the trunk-side configuration you need.
• Test & Save Connection — checks that the SIP endpoint resolves to a public address and accepts connections on the chosen port, then saves. It does not place a call; make a real test call after importing a number.

IP allowlisting and trunk authentication#

ThunderPhone's SIP edge runs on LiveKit Cloud. Some carriers (DIDWW, Telnyx IP-auth connections, most PBXs behind a firewall) only accept SIP traffic from addresses you allowlist, or authenticate outbound calls by source IP. Allow every range below, for both SIP signaling and media (RTP):

LiveKit applies these ranges to Realtime, SIP signaling and media and Webhooks, and they cover calls handled in its Canada, EU, India, Japan and US regions. Region names for a pinned endpoint: canada, eu, india, japan, us.

A few rules of thumb for the trunk itself:

• ThunderPhone does not register. It never sends SIP REGISTER to your carrier, so configure the trunk for IP-based and/or credential (username + password) authentication, not registration.
• Outbound calls should use credentials. Enable username/password authentication on the carrier side and enter the same values in the manual SIP form. Treat the IP allowlist as a second layer, not the only one — outbound calls to destinations outside the covered regions may originate from other addresses.
• Inbound is the reverse direction. The Allowed Source IPs field in the form is where you enter your carrier's signaling addresses so ThunderPhone only accepts calls from them.

The ranges are published by LiveKit at Regions, regional endpoints, and static IPs; ThunderPhone checks that page weekly and updates this guide when it changes.

After connecting#

Import numbers from Phone Numbers → Add number → Connect VoIP provider (or straight from the connection). Imported numbers are verified with a round-trip check, then support inbound and outbound — which unlocks outbound campaigns and programmatic outbound calls.

Next steps#