How Do You Connect Your Existing Phone System to Kickcall Using SIP?

Connect a number from your own phone system to Kickcall through SIP

Written By Maruf Ansari

Last updated About 2 hours ago

Want your AI agents to answer a number from your own phone system? Connect via SIP lets you add that number to Telephony using SIP Registration or SIP Trunking. This guide shows you how to connect the number, check it's working and assign your agents.

Connect SIP Overview

The Connect SIP feature allows you to connect your existing phone system to Kickcall and route calls to your AI agents without transferring your number to a new carrier. You can connect through SIP Registration, which uses credentials provided by your telephony provider, or SIP Trunking, which connects your phone system directly and is recommended in most cases. Once connected, you can verify the SIP registration status, assign agents, and test calls. Incorrect SIP settings can cause connection failures and prevent calls from reaching your agents. This guide is intended for Business users and telephony administrators who manage phone systems.

Important notes

Each number uses one method — not both.
Treat SIP passwords as secrets. Don't share them in tickets or screenshots.
For outbound calls, whitelist the ranges in IP Whitelisting.

Before you start

SIP Registration: the phone number, username, password and proxy from your provider, plus an authentication username or outbound proxy if your provider uses them.
SIP Trunking: your phone numbers and either the IP addresses of your phone system or an auth username and password.
Access to your phone system's settings.

Open the panel

Go to Telephony, click + Add and choose Connect via SIP (SIP Registration or SIP Trunking).

Select the SIP Registration or SIP Trunking tab.

Connect with SIP Registration

Choose Phone or Extension

Enter the Phone Number and, optionally, a Friendly Name.

Enter the Username and Password from your provider, and an Authentication Username only if it's different from the username.

Enter the Proxy, and an Outbound Proxy if your provider uses one. Click Register Line.

Full field details: SIP Registration Setup Guide.

Connect with SIP Trunking

Turn on Inbound Configuration (Origination).

Inbound Configuration (Origination) in SIP Trunking

Enter one or more Phone Numbers (click + to add more) and, optionally, a Friendly Name.

Add Allowed Addresses (IP addresses or CIDR blocks), or an Auth Username and Auth Password.

Copy the Originating URL and enter it in your phone system as the destination for calls.

Set up Outbound Configuration (Termination) if your agent needs to make calls. Click Connect Number.

Full field details: SIP Trunking Setup Guide.

Expected result

The number appears in the Numbers list with a SIP tag and SIP Registered (green tick).

Verify the result

Check the number shows SIP Registered, not SIP Failed.
Place a test call and confirm your agent answers.

Troubleshooting

Problem or Symptom	Likely cause	Solution
Number shows SIP Failed	Wrong username, password or proxy, or (trunking) wrong allowed addresses.	Check the details with your provider and update them.
Inbound calls don't arrive (trunking)	Your phone system isn't sending calls to the Originating URL.	Enter the Originating URL in your phone system and retest.
Outbound calls fail	Our IP ranges aren't whitelisted.	Whitelist the ranges in IP Whitelisting.
Registered but calls aren't answered	No Inbound Call Agent saved.	Select an agent and click Save Changes.

Recovery or rollback

To fix wrong SIP details, correct them with your provider's values and retest.
To switch methods, remove the number and connect it again with the other method.

Frequently Asked Questions

Which tab should I choose?

Choose SIP Trunking if your phone system supports it. Use SIP Registration if your provider only gives you device-style login details.

Can I add texting to a SIP number?

Yes, in the US and Canada, with Host SMS. See Host SMS.

Can I use both methods for one number?

No. Each number uses one method.

Who gives me the SIP details?

Your phone system or carrier. Your Agency can help if you're unsure.

What does SIP Failed mean?

The connection isn't working, so calls won't reach your agents until you fix the SIP details.

SIP Connectivity Overview
Numbers
IP Whitelisting
Host SMS

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