写了一个双工通信的WCF服务接口，在Silverlight调用此服务完全没问题，但在asp.net Web项目中调用服务就报错：请求因 HTTP 状态 415 失败: Unsupported Media Type。

服务配置：
 <services>
      <service name="ReceiveData.IReceiveDataService">
        <endpoint
           address="http://localhost:21443/ReceiveDataService.svc"
           binding="pollingDuplexHttpBinding"
           contract="ReceiveData.IReceiveDataService">
        </endpoint>
        <endpoint
            address="mex"
            binding="mexHttpBinding"
            contract="IMetadataExchange"/>
      </service>
 
    </services>
    <extensions>
      <bindingExtensions>
        <add name=
            "pollingDuplexHttpBinding"
            type="System.ServiceModel.Configuration.PollingDuplexHttpBindingCollectionElement,System.ServiceModel.PollingDuplex, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" />
      </bindingExtensions>
    </extensions>

    <bindings>
      <pollingDuplexHttpBinding>
        <binding name="multipleMessagesPerPollPollingDuplexHttpBinding"
                 duplexMode="MultipleMessagesPerPoll"
                 maxOutputDelay="00:00:07"/>
      </pollingDuplexHttpBinding>
    </bindings>

是pollingDuplexHttpBinding的通信服务只支持Silverlight，还是在asp.net项目中需要配置什么才能调用吗？求大虾给提示，谢谢！！