POST /fax/v5 HTTP/1.1 
Content-Type: "application/soap+xml; charset=utf-8"
Content-Length: length
x-ch-request-id: "{optional unique identifier}"
SOAPAction: ""

<?xml version="1.0" encoding="utf-8"?> 
<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/"
              xmlns="urn:FaxWS">
<soap:Header/>
<soap:Body>
    <CheckService />
</soap:Body>
</soap:Envelope>