<system.diagnostics>
<sources>
    <source name="System.ServiceModel" switchValue="Warning" propagateActivity="true">
    <listeners>
        <add name="xml" />
    </listeners>
    </source>
</sources>
<sharedListeners>
    <add name="xml" type="System.Diagnostics.XmlWriterTraceListener" initializeData="d:\temp\wcf.svclog" />
</sharedListeners>
</system.diagnostics>