Nicholas Allen's Indigo Blog

Inside the Standard Bindings: WSHttp

The WsHttp binding is a lot like the BasicHttp binding with the Web Services knob turned up a little higher. Where BasicHttp stops with message security, WsHttp continues with transactions, reliable messaging, and WS-Addressing either enabled by default or available through a single control setting. Otherwise, the HTTP-ness of the two bindings is the same and all of the binding elements being used have appeared in previous bindings.

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.

I'll start with my usual approach of presenting the channel stack and baseline settings with the Security.Mode property set to SecurityMode.None. The important points to note here are that we've got a binding element for transactions (with the transaction protocol set to the WS standard rather than OLE transactions) and the mapping mode is now SoapWithWSAddressing.

1. System.ServiceModel.Channels.TransactionFlowBindingElement

   TransactionProtocol: WSAtomicTransactions
   

2. 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
   

3. 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
   

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
ReliableSession: 
  Enabled: False
SendTimeout: 00:01:00
TextEncoding: System.Text.UTF8Encoding
TransactionFlow: False

Except for the differences in addressing, all of the features that are on by default in the WsHttp binding match the BasicHttp binding. This is still true when we set the SecurityMode to Transport, although you have to pretend like that transaction binding element isn't there.

1. System.ServiceModel.Channels.TransactionFlowBindingElement
2. System.ServiceModel.Channels.TextMessageEncodingBindingElement
3. System.ServiceModel.Channels.HttpsTransportBindingElement

   RequireClientCertificate: False
   Scheme: https
   

However, when we switch to Message security, a slight divergence begins to appear. The message security implementation is more like the one we saw with the NetTcp binding.

1. System.ServiceModel.Channels.TransactionFlowBindingElement
2. System.ServiceModel.Channels.SymmetricSecurityBindingElement
3. System.ServiceModel.Channels.TextMessageEncodingBindingElement
4. System.ServiceModel.Channels.HttpTransportBindingElement

Moving to the TransportWithMessageCredential security mode brings us back into line with the BasicHttp binding though.

1. System.ServiceModel.Channels.TransactionFlowBindingElement
2. System.ServiceModel.Channels.TransportSecurityBindingElement
3. System.ServiceModel.Channels.TextMessageEncodingBindingElement
4. System.ServiceModel.Channels.HttpsTransportBindingElement

   RequireClientCertificate: False
   Scheme: https
   

To finish things up, I tried bindings with the security mode again set to None and enabling either the reliable message or MTOM features.

1. System.ServiceModel.Channels.TransactionFlowBindingElement
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.TextMessageEncodingBindingElement
4. System.ServiceModel.Channels.HttpTransportBindingElement

1. System.ServiceModel.Channels.TransactionFlowBindingElement
2. System.ServiceModel.Channels.MtomMessageEncodingBindingElement
3. System.ServiceModel.Channels.HttpTransportBindingElement

There's nothing special going on here that we haven't seen before.

Next week is going to be TechEd in Boston. There's no planned schedule of topics although I'll continue to try to write a new entry each day. After TechEd, I have some short topics about our transports before we get back into the series on the standard bindings.

Some time in the future: Framing Size Limits for the Tcp and Named Pipe Transports