# How to configure signal encryption via TLS

Transport Layer Security (TLS) is a security protocol used for encrypted data transmission over the Internet. It is the successor to SSL and ensures that third parties cannot easily access your SIP data. Currently, TCP/TLS connections are only available via IPv4 and not IPv6.

To set up TLS on your phone, router, or VoIP app, follow these steps

**-> Registrar/Domain:** Enter sipgate.co.uk

**-> Proxy/Outbound Proxy:** Enter sip.sipgate.co.uk

**-> Change Protocol:** On some devices, you may need to switch the signaling protocol from UDP to TLS.

#### Encrypting media data (SRTP)

With encrypted signaling, we also require voice data to be encrypted. Depending on your device, encryption may be enabled automatically. If manual configuration is needed, set **SRTP** in your device settings. If this setting is incorrect, calls will fail with the error **488 Not Acceptable Here**.

#### Exceptions

The following devices do not support TLS configuration

* **Speedport W7XX & W9XX**: No second server or TLS settings available.
* **Speedport Hybrid**: No second server or TLS settings available.
* **Speedport Pro**: No second server or TLS settings available.
* **Fritz!Box**: Requires at least firmware version 7.23 to enable TLS.
* **Zoiper Android**: Fails TLS registration with SIP 408 Timeout.