payload = [[POST /upnp/control/rendertransport1 HTTP/1.1
SOAPACTION: "urn:schemas-upnp-org:service:AVTransport:1#SetAVTransportURI"
CONTENT-TYPE: text/xml ; charset="utf-8"
Content-Length: 347

<s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/" s:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/"><s:Body><u:SetAVTransportURI xmlns:u="urn:schemas-upnp-org:service:AVTransport:1"><InstanceID/><CurrentURI>http://www.verarscht.org/tts/abend.mp3</CurrentURI><CurrentURIMetaData/></u:SetAVTransportURI></s:Body></s:Envelope>]]