WCF and Silverlight - Binary Encoding

I have an odd problem. I am switching from HttpBasicEncoding to binary encoding. When I switch to use binary message encoding, I have noticed in Fiddler that my body of the response is 20x LARGER than the HttpBasicEncoding Equivalent. Here are my settings on the server:

When using Basic Encoding

<endpoint address="" binding="basicHttpBinding" bindingConfiguration="MyBinding"
  contract="MyProduct.MyService" />

...

<basicHttpBinding>
  <binding name="MyBinding">
    <security mode="TransportCredentialOnly" />
  </binding>
</basicHttpBinding>

When Using Binary Encoding

<customBinding>
  <binding name="MyBinaryBinding">
    <binaryMessageEncoding />
    <httpTransport />
  </binding>
</customBinding>

<endpoint address="" binding="customBinding" bindingConfiguration="MyBinaryBinding"
  contract="MyProduct.MyService" />

In the Silverlight application, I need to programmatically build the binding. Here is how I am building those bindings:

When using Basic Encoding

BasicHttpBinding binding = new BasicHttpBinding();
binding.Security.Mode = BasicHttpSecurityMode.None;

// Wireup request

When using Binary Encoding

HttpTransportBindingElement transportElement = new HttpTransportBindingElement();
  transportElement.MaxReceivedMessageSize = int.MaxValue;
  transportElement.MaxBufferSize = int.MaxValue;

  CustomBinding binding = new CustomBinding();
  binding.Elements.Add(new BinaryMessageEncodingBindingElement());
  binding.Elements.Add(transportElement);

  // Wireup request

What am I doing wrong? Why is binary encoding response so much larger in size than the HTTP response?

Th开发者_运维知识库ank you!

---

BinaryFormatter and NetDataContractSerializer include a lot of type metadata and field info, and it adds up. For generating much smaller binary, I would recommend protobuf-net (disclosure: in the author), but note that I don't have a direct serializer swap-in for WCF on Silverlight so you would has to send byte[] as the args and handle manually, but it is small and fast. I want to improve that area.

Actually, with that setup regular http binding is then better, especially if you can enable MTOM. I hope to improve the Silverlight usage in time.