4 to 3, upgrade
POST /asmx/simple.asmx HTTP/1.1
Host: mssoapinterop.org
Content-type: application/soap+xml
Content-length: 10
<abcdef/>
HTTP/1.1 100 Continue
Server: Microsoft-IIS/5.0
Date: Fri, 04 Apr 2003 16:33:19 GMT
X-Powered-By: ASP.NET
HTTP/1.1 500 Internal Server Error.
Server: Microsoft-IIS/5.0
Date: Fri, 04 Apr 2003 16:33:19 GMT
X-Powered-By: ASP.NET
X-AspNet-Version: 1.2.30327
Cache-Control: private
Content-Type: text/xml; charset=utf-8
Content-Length: 954
<?xml version="1.0" encoding="utf-8"?>
<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<soap:Header>
<upg:Upgrade xmlns:upg="http://www.w3.org/2002/12/soap-upgrade">
<SupportedEnvelope qname="soap:Envelope"
xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/"
xmlns="http://www.w3.org/2002/12/soap-envelope" />
<SupportedEnvelope qname="soap12:Envelope"
xmlns:soap12="http://www.w3.org/2002/12/soap-envelope"
xmlns="http://www.w3.org/2002/12/soap-envelope" />
</upg:Upgrade>
</soap:Header>
<soap:Body>
<soap:Fault>
<faultcode>soap:VersionMismatch</faultcode>
<faultstring>Possible SOAP version mismatch: Envelope namespace was unexpected. Expecting http://schemas.xmlsoap.org/soap/envelope/.</faultstring>
<detail />
</soap:Fault>
</soap:Body>
</soap:Envelope>