// Add following config to your WCF app config file , Since we use System.net API also ,you can trace System.net API calls to debug WCF apps

<configuration>
<system.diagnostics>
    <trace autoflush="true" />
        <sources>
            <source name="System.Net">
                <listeners>
                    <add name="System.Net"/>
                </listeners>
            </source>
            <source name="System.Net.HttpListener">
                <listeners>
                    <add name="System.Net"/>
                </listeners>
            </source>
            <source name="System.Net.Sockets">
                <listeners>
                    <add name="System.Net"/>
                </listeners>
            </source>
            <source name="System.Net.Cache">
                <listeners>
                    <add name="System.Net"/>
                </listeners>
            </source>
        </sources>
        <sharedListeners>
            <add
                name="System.Net"
                type="System.Diagnostics.TextWriterTraceListener"
                initializeData="System.Net.trace.log"
                traceOutputOptions="DateTime"
            />
        </sharedListeners>
        <switches>
            <add name="System.Net" value="Verbose" />
            <add name="System.Net.Sockets" value="Verbose" />
            <add name="System.Net.Cache" value="Verbose" />
            <add name="System.Net.HttpListener" value="Verbose" />
        </switches>
</system.diagnostics>
</configuration>