Encrypted calling

What can I do here?

Everyone can use encryption, provided the devices support it.

The technology

TLS and SRTP support have been added to the platform for call encryption. Only when both options are properly configured, calls are fully encrypted from the phone to the platform. Traffic from the platform to another customer without encryption is not secure.

TLS

Adding TLS support means that the SIP signaling is encrypted. This prevents others from determining who is calling whom and how long the call lasted.

SRTP

SRTP means that the audio of a call is encrypted between the PBX and the VoIP device/VoIP client used for calling. To use SRTP, a Key Negotiation Protocol must be used. The standard for VoIP in this regard is SDES. SDES sends the keys used via SIP signaling. Because TLS is also enabled for signaling, these keys are transmitted in encrypted form.

Installation

Secure calling is only possible when the device supports it. To enable secure calling on a device, the default settings must be changed. Each device, type, and brand uses different settings. In practice, it sometimes appears impossible to make secure calls with older devices. This is always due to the device itself.

Follow these steps to enable secure calling:

First, we'll set up encrypted calling in Freedom

• Log in to Freedom.
• Click on Admin in the menu bar.
• Go to VoIP account.
• Select the account you want to use for encrypted calling.
• Select the Advanced SIP settings tab.
• Check the box next to Force encryption.

• You'll now see a popup indicating that changes need to be made to your phone.
• Click Continue.
• Click Save at the bottom of the page.

Next, continue with the device settings

1. Both TLS and SRTP must be activated in a device. These options are often found under different tabs in the web interface of the devices.

2. The proxy address must be changed to sip.encryptedsip.com:5061.

3. After the device has received the correct settings, [Force encryption] must be checked under advanced settings.

(NOTE: Once the devices are configured for encrypted calling and you uncheck the box? Then you can no longer make or receive calls! (Both the portal and device settings must have the same intention: encryption on or encryption off. A combination of both settings causes problems, such as with accepting a call, even though the device is ringing.)

4. You can now make secure calls.