# 31922: Stream - WebSocket - URL Schema Not Supported

Log Type: APPLICATION

Log Level: ERROR

## Description

This error occurs when the `<Stream>` `url` uses a protocol that Programmable Voice Media Streams does not support. Twilio connects Media Streams over a `wss` WebSocket connection, and `wss` is the only supported protocol for the `<Stream>` `url` attribute.

### Possible causes

* The `<Stream>` `url` uses a protocol other than `wss`.
* The WebSocket endpoint in your TwiML was configured with an unsupported URL schema.

### Possible solutions

* Update the `<Stream>` `url` so it points to a secure WebSocket endpoint that uses the `wss` schema.
* Review the `url` attribute in your `<Start><Stream>` or `<Connect><Stream>` TwiML and confirm it is formatted for Media Streams.
* If you need to pass values to your WebSocket server, do not add query string parameters to the `url`. Use nested `<Parameter>` values instead.

#### Additional resources

* [TwiML `<Stream>`](/docs/voice/twiml/stream)
* [Media Streams Overview](/docs/voice/media-streams)
* [Media Streams WebSocket Messages](/docs/voice/media-streams/websocket-messages)