Linphone VOIP Guide


If you have been following the steps in Extreme Privacy, you might possess VOIP telephone service through Twilio or Telnyx. You now need a way to make and receive voice calls over this new number. I prefer Linphone for this. The following infomation has been extracted from Extreme Privacy, with several updates added since the original publication. This online tutorial should replace the printed text from the book.

Once you have a SIP domain and credentials created which allow you to associate your Twilio or Telnyx account with VOIP software called Linphone (linphone.org). Navigate to this website and download the desired application for your environment, including Linux, macOS, Windows, Android, and iOS. It can be downloaded to GrapheneOS device through F-Droid. The following configuration steps should apply to all Linphone applications, but you may see minor variations across platforms. You will need to repeat each step on every device which you want to use for VOIP calling. The following applies to Twilio numbers, but can be modified for Telnyx following the tutorial in the book.

• If prompted upon launch of Linphone, choose “Account Assistant”.
• Click the “Use a SIP Account”.
• Enter a “Username” of your number, such as “2025551212”.
• Enter a “Display Name” of your telephone number, such as “2025551212”.
• Enter a “SIP Domain” of your full domain including your username and the closest server location as previously explained. I used 2025551212.sip.us1.twilio.com. Replace “2025551212” with your own number and “us1” with your server.
• Enter the “Password” you previously created for the credential account.
• Change the “Transport” to “TLS”.

Click the confirmations until you return to the main application. You can now click the upper left corner in order to select your new account, or choose between multiple accounts if you add more. You should see a green or grey light next to the account if the connection from Linphone to Twilio is successful. We can now make our first test call.

• Confirm that your Twilio account is selected within the Linphone application.
• In the search field at the top, input any known telephone number.
• Click the “phone” button to initiate a call.

You should receive an automated message thanking you for using your demo account. This confirms that we can place calls to Twilio’s servers, but we are far from unlimited usage to real numbers. We are now ready to attempt a stricter test call. You still cannot call any real number, but you should be able to place a call to any “Verified” number. If you provided a Google Voice number during account creation, that number is automatically verified. If you did not, complete the following within your Twilio dashboard to add a verified number for testing.

• Click “Phone Numbers” > “Manage” > “Verified Caller IDs” in the left menu.
• Add a new number which can be accessed.
• Confirm whether you prefer a call or text and verify the call or text to add the number.

Return to your Linphone application and attempt a call to the number which you have verified with Twilio. After a brief message about the trial account, the call should go through. If you can complete a test call to your own number, your configuration is complete. You are now restricted to only calling verified numbers. I have seen this fail with some VOIP numbers. If this happens to you, do not be alarmed. As long as you receive a confirmed test call message from Twilio, your configuration is complete. If you would like to remove all restrictions to make and receive calls to and from any number, you must “Upgrade” the account. The following should be conducted within the Twilio portal.

• Return to the Dashboard in the upper left menu.
• Click the “upgrade” link and provide all requested billing details.
• Provide any credit, debit, or registered prepaid card.
• Apply $20 to the account.

You should now have an unrestricted Twilio account which should be fully functional for voice calls. Please do not upgrade the account until you know your test calls are going through. You should also have a fully functional VOIP application which can facilitate calls. Linphone can be used to place a call at any time from any device. Replicate your Linphone settings on as many mobile and desktop environments as you desire. Furthermore, you can add as many numbers as you wish by repeating this process.Incoming calls will “ring” your mobile device or desktop as long as the Linphone application is open and your status is “green”.

Please think of this VOIP strategy as being similar to landline service. While configuring Twilio within the Linphone application during testing of this strategy, I encountered several devices which presented authentication errors during usage. These usually claim that the Twilio credentials supplied to Linphone have failed and the user is prompted to enter the correct password. Supplying the appropriate password fails. This appears to be an issue with Twilio temporarily blocking access due to too many invalid attempts, incorrect protocol settings, or launching and closing of Linphone from mobile devices too many times within a sixty minute threshold. Any account restrictions should reset after twenty minutes of inactivity, but the following settings within Linphone should mitigate these issues. These settings can appear within various options in the menu of each operating system’s version of the Linphone application, and the exact paths might change.

Linphone-Android:

• Menu>Settings>Network>Allow IPv6: Disabled
• Menu>Settings>Network>Use random ports: Disabled
• Menu>Settings>Network>SIP port: 5060

Linphone-iOS:

• Menu>Settings>Network>Random Port: Disabled
• Menu>Settings>Network>Port: 5060
• Menu>Settings>Network>Allow IPv6: Disabled
• Menu>Settings>SIP Accounts>(Account)>More Options: Enabled
• Menu>Settings>SIP Accounts>(Account)>Account Enabled: Enabled
• Menu>Settings>SIP Accounts>(Account)>Push Notification: Disabled

Linphone-Desktop (Windows/Mac/Linux)

• Settings>SIP Accounts>Proxy Accounts>Edit>Register: Enabled
• Settings>SIP Accounts>Proxy Accounts>Edit>Publish presence: Enabled
• Settings>SIP Accounts>Proxy Accounts>Edit>NAT and Firewall: All Disabled

ALL Devices:

• Transport: TLS
• ICE/AVPF/STUN/TURN: Disabled
• Outbound Proxy: Disabled

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