How to test Websocket plugin

I’m using Openfire 3.10.0 and I’ve installed Websocket plugin. It seems that this plugin doesn’t respond on incoming connections.

I use to test the connection: Echo Test - Powered by Kaazing
The URL I specify in the test form is: ws://
The connection couldn’t be established.

The port 7070 is accessible for external incoming connections (at least I can connect to it via telnet from outside server).
HTTP binding is enabled in Openfire settings (and it works well on my website but I want to implement the websocket connections).

What I’m doing wrong?
Please help!