WCF service stop sending web requests once it's hosted in IIS

I have a WCF service that receive query from a silverlight client and send the query to a Search API (Bing, or Google), process the search results to return those back to the silverlight client.

Everything works find in Visual Studio.

Once I publish the service in IIS, I can access the service endpoint and the silverlight client to talk to the service as well. However, the service does not send any query to the Search API. I opened Fiddler to monitor the traffic. There is no web request send to search API.

Is there any setting in IIS, or firewall, that I neglected?

The web.config is attached below:

<?xml version="1.0" encoding="utf-8" ?>
<configuration>  
<system.serviceModel>
    <behaviors>
        <serviceBehaviors>
            <behavior name="SiteRankerBehavior">
                <serviceMetadata httpGetEnabled="true开发者_StackOverflow中文版" />
                <serviceDebug includeExceptionDetailInFaults="true" />                  
            </behavior>              
        </serviceBehaviors>
    </behaviors>
    <services>
        <service behaviorConfiguration="SiteRankerBehavior" name="SiteDiscovery.SiteRanker">
            <endpoint address="" binding="basicHttpBinding" contract="SiteDiscovery.ISiteRanker">                   
            </endpoint>
            <endpoint address="mex" binding="mexHttpBinding" contract="IMetadataExchange" />
        </service>
    </services>
</system.serviceModel>

Thanks Sarah

Ok, I found the solution here that exactly solved my problem. Basically, I need to add the following to web.config and everything works.

<system.net>
    <defaultProxy>
        <proxy usessystemdefault="False" proxyaddress="http://your-proxy-name.domain.com:port-number-if-any" bypassonlocal="True" autoDetect="False" /> 
    </defaultProxy>
</system.net>

Why it worked in Visual Studio is still a mystery to me though. Strickly speaking, it worked before in Visual Studio if the Fiddler is running at the same time.