<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>