Nicholas Allen's Indigo Blog

Inside the Standard Bindings: WSDualHttp

After a few days break, the series on standard bindings continues. This week will take care of the remainder of the HTTP bindings, leaving only the MSMQ and PeerChannel bindings to talk about. WSDualHttp features the same support for Web Service protocols as the WSHttp binding, but is designed for use with duplex contracts.

Standard disclaimer:

I've cut down on the number of properties presented by eliminating duplicates between the binding settings and binding element settings. For instance, the XML reader quotas can be set on either the binding or the message encoder binding element, but I'm only going to show them on the message encoder. I've also omitted most of the security credential settings because they're very messy and you hopefully won't need to change them much.

Unlike WSHttp, WSDualHttp only supports SOAP security. I'll start off with the settings when no security is being used. The other two big differences you'll see between WSHttp and WSDualHttp is that the dual variety makes Reliable Messaging mandatory and adds a CompositeDuplex binding element to provide the duplex shape.

1. System.ServiceModel.Channels.TransactionFlowBindingElement

   TransactionProtocol: WSAtomicTransactions
   

2. System.ServiceModel.Channels.ReliableSessionBindingElement

   AcknowledgementInterval: 00:00:00.2000000
   EnableFlowControl: True
   InactivityTimeout: 00:10:00
   MaxPendingChannels: 128
   MaxRetryCount: 8
   MaxTransferWindowSize: 32
   Ordered: True
   

3. System.ServiceModel.Channels.CompositeDuplexBindingElement

   ClientBaseAddress: 
   

4. System.ServiceModel.Channels.TextMessageEncodingBindingElement

   AddressingVersion: Addressing10 (http://www.w3.org/2005/08/addressing)
   MaxReadPoolSize: 64
   MaxWritePoolSize: 16
   ReaderQuotas: 
     MaxArrayLength: 16384
     MaxBytesPerRead: 4096
     MaxDepth: 32
     MaxNameTableCharCount: 16384
     MaxStringContentLength: 8192
   

5. System.ServiceModel.Channels.HttpTransportBindingElement

   AllowCookies: False
   AuthenticationScheme: Anonymous
   BypassProxyOnLocal: False
   HostNameComparisonMode: StrongWildcard
   ManualAddressing: False
   MappingMode: SoapWithWSAddressing
   MaxBufferPoolSize: 524288
   MaxBufferSize: 65536
   MaxReceivedMessageSize: 65536
   ProxyAddress: 
   ProxyAuthenticationScheme: Anonymous
   Realm: 
   Scheme: http
   TransferMode: Buffered
   UnsafeConnectionNtlmAuthentication: False
   UseDefaultWebProxy: True
   

The CompositeDuplex element creates the back channel from the server to the client using the base address setting. Most configuration settings are unchanged from the ones used with the WSHttp binding except that there is no longer a switch to disable reliable sessions.

CloseTimeout: 00:01:00
EnvelopeVersion: Soap12 (http://www.w3.org/2003/05/soap-envelope)
Namespace: http://tempuri.org/
OpenTimeout: 00:01:00
ReceiveTimeout: 00:01:00
SendTimeout: 00:01:00
TextEncoding: System.Text.UTF8Encoding
TransactionFlow: False

Setting the Security.Mode to Message makes exactly the same transformation as we've seen with the other standard bindings.

1. System.ServiceModel.Channels.TransactionFlowBindingElement
2. System.ServiceModel.Channels.ReliableSessionBindingElement
3. System.ServiceModel.Channels.SymmetricSecurityBindingElement
4. System.ServiceModel.Channels.CompositeDuplexBindingElement
5. System.ServiceModel.Channels.TextMessageEncodingBindingElement
6. System.ServiceModel.Channels.HttpTransportBindingElement

The same holds true for changing the message encoding to use MTOM.

1. System.ServiceModel.Channels.TransactionFlowBindingElement
2. System.ServiceModel.Channels.ReliableSessionBindingElement
3. System.ServiceModel.Channels.CompositeDuplexBindingElement
4. System.ServiceModel.Channels.MtomMessageEncodingBindingElement
5. System.ServiceModel.Channels.HttpTransportBindingElement

Next time: Inside the Standard Bindings: WSFederationHttp