Karlosp.net

First install VLC player
* Insert about:config in the address bar

* Right click on the list, select New, then Boolean; insert network.protocol-handler.external.mms as Preference Name and true as Value

* Now another right click, select New and String; insert network.protocol-handler.app.mms as Preference Name and /usr/bin/vlc (path to where the file is installed on your system) as Value.