A WCF durable service is a service in which the state is maintained during the different calls. Using Context enabled bindings you can create WCF Durable Services.
Using Context enabled bindings you can send extra parameters to the service to exchange context by using the HttpCookies or the SOAP Header
The following are the context bindings used for durable wcf services.
1. BasicHttpContextBinding
2. NetTcpContextBinding
3. WSHttpContextBinding
Ref:
Context Enabled Bindings and Durable Services
