How to read streams in parallel at client from a WCF Service Method, without blocking each other?

Question

I'm trying to create a download application, in which there would be four or more download queues using which a user can download files from the server. What would be best possible solution to accomplish this without letting the queues blocking each other. I'm starting every download queue in a different background thread which reports progress to the WPF Client UI as the bytes are getting downloaded from service. But, a new download queue blocks any previously running download Queue. I've tried to search a lot on google and StackOverflow but, still not able to resolve the issue

Methodology Applied: We are using Windows Azure Service Bus to connect to our WCF service using the NetTcpRelayBinding.

Client Side Configuration:

<system.serviceModel>
    <bindings>
      <!-- Application Binding -->
      <netTcpRelayBinding>
        <binding name="default" 
                 connectionMode="Hybrid" 
                 maxReceivedMessageSize="2147483647" 
                 transferMode="Streamed" 
                 closeTimeout="01:00:00" 
                 openTimeout="00:30:00" 
                 sendTimeout="infinite" 
                 receiveTimeout="infinite" 
                 maxBufferPoolSize="2147483647" 
                 maxBufferSize="2147483647" 
                 maxConnections="500"
                 listenBacklog="200">

          <security mode="None"/>
          <readerQuotas maxBytesPerRead="2147483647" maxStringContentLength="2147483647" maxArrayLength="2147483647" />
          <reliableSession enabled="false" ordered="true" />
        </binding>
      </netTcpRelayBinding>
    </bindings>
    <client>
      <!-- Application Service -->
      <endpoint name="RelayEndpoint" contract="DDMInterface.IBaseService" binding="netTcpRelayBinding" bindingConfiguration="default" address="" />
    </client>

Service Configuration:

<system.serviceModel>

    <bindings>
      <!-- Application Binding -->
      <netTcpRelayBinding>
        <binding name="default" 
                 connectionMode="Hybrid" 
                 maxReceivedMessageSize="2147483647"
                 transferMode="Streamed"
                 closeTimeout="01:00:00"
                 openTimeout="00:30:00"
                 sendTimeout="infinite"
                 receiveTimeout="infinite"
                 maxBufferPoolSize="2147483647" 
                 maxBufferSize="2147483647"
                 maxConnections="500"
                 listenBacklog="200">

          <security mode="None"/>
          <readerQuotas maxBytesPerRead="2147483647" maxStringContentLength="2147483647" maxArrayLength="2147483647" />
          <reliableSession enabled="false" ordered="true" />
        </binding>
      </netTcpRelayBinding>
    </bindings>

    <services>
      <!-- Application Service -->
      <service name="DDMService.DDMBaseService" behaviorConfiguration="ThrottleBehavior">
        <endpoint name="RelayEndpoint"
                  contract="DDMInterface.IBaseService"
                  binding="netTcpRelayBinding"
                  bindingConfiguration="default"
                  address=""/> <!--behaviorConfiguration="defaultBehavior"-->
      </service>
    </services>

    <behaviors>
      <serviceBehaviors>
        <behavior name="ThrottleBehavior">
          <serviceThrottling maxConcurrentCalls="2147483647" maxConcurrentInstances="2147483647" />
          <!--maxConcurrentSessions="2147483647"-->
        </behavior>
      </serviceBehaviors>
      <endpointBehaviors>
        <behavior name="defaultBehavior">
          <dispatcherSynchronization asynchronousSendEnabled="true"/>
        </behavior>
      </endpointBehaviors>
    </behaviors>

Service Behavior:

[ServiceBehavior(InstanceContextMode = InstanceContextMode.PerCall, ConcurrencyMode = ConcurrencyMode.Multiple)]
    public class DDMBaseService : IBaseService
    {   

I've been banging my head since past 2 weeks on this problem and still not able to resolve it. Please help me finding a proper approach by suggesting links or solutions. Please ask any more information if required. Thanks in advance...

Answer 1

UPDATE I tried debugging the code more and more and found that the downloads were indeed working in parallel but were not getting reflected at the UI. I corrected that problem.