Use your own phone number with SIP

Already have a phone number with a carrier or a business phone system (PBX)? Add it to Kollie under My Numbers, attach it to an agent, and route its calls to the SIP address Kollie shows you. Your customers keep dialling the number they already know, and the AI agent answers.

This is an alternative to call forwarding. Call forwarding sends calls over the public phone network to a phone number Kollie provides. With SIP, your carrier or PBX hands the call straight to Kollie over the internet, and your own number stays the number the agent answers on.

These guides cover inbound calls (your callers reaching the agent).

Call forwarding or SIP?

Provider guides

Step-by-step guides are available for:

• 3CX
• Easybell
• Zadarma
• Twilio
• Telnyx
• Yeastar P-Series
• Peoplefone maintains its own guide for its Elastic SIP Trunk. Where that guide asks for a destination, use the SIP address from your Kollie number card.
• FRITZ!Box: there is no dedicated guide yet. Follow the general steps on this page.

How it works

1. You add your number in Kollie under My Numbers. Kollie creates a number card that shows a SIP address.
2. You attach the number to an agent.
3. Your carrier or PBX sends calls for that number to the SIP address. The dialled number is included in international (E.164) format.
4. Kollie matches the dialled number to your number card, and the attached agent answers.

There is no login between your system and Kollie: no username, no password, no SIP registration. In your phone system, this kind of connection is usually called a static trunk, peer trunk, IP-based trunk, SIP peer or trusted trunk. If your system offers both a registration-based trunk and one of these, choose the static one.

Your system only supports registration-based trunks? Contact support and we'll look at the options with you.

Step 1: Add your number in Kollie

1. In the side menu, open My Numbers.

2. Click Add Your Number.

3. In the Add Your Number dialog, pick the country with the flag selector. The country code is filled in for you. Then enter the rest of your number without the leading zero (for example +31 970 1025 4023, not +31 0970 …).

   

4. Click Add.

Your number now appears as a card labelled Your number:

5. Attach the number to an agent. Once it is attached, the Agent row shows the agent's name. A number without an agent cannot answer calls.

   

   

Step 2: Route calls to the SIP address

Every carrier and phone system does this a little differently, so follow the matching provider guides. These rules apply to all of them.

Use the SIP address from your number card

Copy it with the copy icon on the card. What you enter depends on what the field in your system asks for:

Use TCP

Set the SIP transport on your trunk or connection to TCP. If your system allows several protocols on one trunk, turn the others off.

Send the number in E.164 format

The number your system sends must match the number on your card exactly: +, the country code, and the number without the leading zero.

Pass the original caller ID

Make sure your system sends the caller's own number, not your business number. Otherwise every call looks as if it comes from you, and skills such as Get Contact by Phone Number, HubSpot contact matching and per-caller personalisation stop working.

Allow Kollie through your firewall (only if you restrict traffic)

Kollie's calls are carried by LiveKit Cloud (shown as Routed by: LiveKit on the number card). If your firewall or Session Border Controller (SBC) only accepts traffic from known addresses, allow these ranges:

143.223.88.0/21
161.115.160.0/19
153.57.128.0/18

• Allow both SIP signalling and audio (media), over UDP and TCP. Calls use TCP for signalling, but the audio travels separately.
• If even one range is blocked, calls may not arrive, or they may connect without audio.
• LiveKit publishes these ranges and may update them. You can always find the current list in LiveKit's "Regions and endpoints" documentation.

If your firewall doesn't restrict incoming SIP traffic, you can skip this.

Step 3: Decide when the agent takes the call

Most phone systems let you choose when calls go to the agent. Common choices:

• Every call to the number
• Only unanswered calls: your team rings first, and the agent takes over if nobody picks up
• Outside business hours
• Overflow from a ring group or queue

The provider guides show where to set this in each system.

Step 4: Test

Call your number from another phone and check:

• The agent attached to the number answers.
• The caller's real number appears in Agent Calls History, not your business number.
• Audio works in both directions.
• If you set up a rule for unanswered calls or out-of-hours calls, it triggers as expected.
• If the agent uses the Call Transfer skill, a transfer back to your team works.

Tip: for every test call, note the date, exact time, caller number and dialled number. With these details, we can find a failed call in our logs quickly.

Kollie connection details

A quick reference for everything above.

Requirements

• A Kollie agent that is already set up.
• A phone number you own, with a carrier or phone system that can send calls to a SIP address over TCP.
• Admin access to your phone system or carrier portal, or a PBX administrator who can make changes.
• If your network restricts SIP traffic: access to your firewall or SBC.

Other phone systems

Your system is not in the provider guides? It can usually still be connected if it:

• can send calls to a SIP address or hostname (a static/peer trunk, or a "forward to SIP URI" option),
• supports TCP for SIP,
• sends the dialled number in E.164 format, and
• accepts audio from the LiveKit ranges, if your firewall restricts traffic.

Get in touch and we'll look at your system with you.

If the connection doesn't work