---
page_type: error
code: 32209
message: "32209: SIP: Secure transport required"
level: ERROR
---

## Description

When secure calling is enabled, Twilio cannot accept calls made using UDP or TCP. Please use TLS.

### Possible Causes

- Media security is enabled on your SIP domain or trunk, but Twilio received SIP traffic over an insecure protocol, such as UDP or TCP.
- You are using SIP registration, and are attempting to place a secure call to an endpoint where all of the available bindings were registered with an insecure protocol, such as UDP or TCP.

### Possible Solutions

- Please ensure your PBX or end device is configured to send SIP traffic over the TLS transport.
- If you are using SIP registration, your device must be configured to _register_ over the TLS protocol. Devices registered over insecure protocols will not be attempted for secure calls.