WCF Peer to peer chat

Question

I wrote some code for a WCF P2P chat program.

<services>
  <service name="PeerChat.Form1">
    <host>
      <baseAddresses>
        <add baseAddress="net.p2p://PeerChat/" />
      </baseAddresses>
    </host>
    <endpoint name="PeerChatEndPoint" address="" binding="netPeerTcpBinding" bindingConfiguration="BindingUnsecure"
       contract="PeerChat.IChatService" />
  </service>
</services>
<bindings>
  <netPeerTcpBinding>
    <binding name="BindingUnsecure">
      <resolver mode="Pnrp" />
      <security mode="None" />
    </binding>
  </netPeerTcpBinding>
</bindings>
<client>
  <endpoint
      name="PeerChatClientEndPoint"
      address="net.p2p://PeerChat/"
      binding="netPeerTcpBinding"
      bindingConfiguration="BindingUnsecure"
      contract="PeerChat.IChatService"
  />
</client>

I then host the service as follows:

[ServiceBehavior(InstanceContextMode = InstanceContextMode.Single)]
public partial class Form1 : Form, IChatService
{

    IChatService channel;
    ServiceHost host = null;
    ChannelFactory<IChatService> channelFactory = null;

    private void StartService()
    {
        //Instantiate new ServiceHost
        host = new ServiceHost(this);
        //Open ServiceHost
        host.Open();
        //Create a ChannelFactory and load the configuration setting
        channelFactory = new ChannelFactory<IChatService>("PeerChatClientEndPoint");
        channel = channelFactory.CreateChannel();
        //Lets others know that someone new has joined
        channel.SendMessage("Hello."+ Environment.NewLine);

        foreach (var cloud in Cloud.GetAvailableClouds())
        {
            textBox2.Text += cloud.Name + Environment.NewLine;
        }
    }
    private void StopService()
    {
        if (host != null)
        {
            channel.SendMessage("Bye." + Environment.NewLine);
            if (host.State != CommunicationState.Closed)
            {
                channelFactory.Close();
                host.Close();
            }
        }
    }

The problem is I can send a message to the same instance of the program but not to another instance. Ie an instance only receives its own messages not messages from other instances. Not sure if it is a matter of configuring PNRP correctly? I tested on Windows 7.

Answer 1

You wouldn't happen to have both instances of the program listening to the same end point would you? I am not certain, but I suspect what may be happening is that your client application is registering itself on the endpoint first, then intercepting all the messages that come to that endpoint before the second one can get them. What I'd suggest trying to do is configuring the second instance to start up on an endpoint with a diferent Uri. So say one connects on net.p2p://PeerChatA/ and the other net.p2p://PeerChatB/ .