// server
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ServiceModel;
using System.ServiceModel.Channels;

public class Tset
{
	public static void Main ()
	{
		ServiceHost host = new ServiceHost (typeof (Foo));
		var b = new CustomBinding (
			new BinaryMessageEncodingBindingElement (),
			new TcpTransportBindingElement ());
		host.AddServiceEndpoint ("IFoo", b, "net.tcp://localhost:8080");
		host.Open ();
		Console.WriteLine ("Hit [CR] key to close ...");
		Console.ReadLine ();
		host.Close ();
	}
}

[ServiceContract (CallbackContract = typeof (IFoo))]
public interface IFoo
{
	[OperationContract]
	string Echo (string msg);
}

class Foo : IFoo
{
	public string Echo (string msg) 
	{
		var c = OperationContext.Current.Channel;
		Console.WriteLine (c.GetType ().GetInterfaces ().Length);
		Console.WriteLine (c is IContextChannel);
		return msg + msg;
	}
}

// client

using System;
using System.ServiceModel;

public class Tset
{
	public static void Main ()
	{
		var binding = new NetTcpBinding ();
		binding.Security.Mode = SecurityMode.None;
		IFoo proxy = new ChannelFactory<IFoo> (
			binding, "net.tcp://localhost:8080/")
			.CreateChannel ();
		Console.WriteLine (proxy.Echo ("TEST FOR ECHO"));
	}
}

[ServiceContract]
public interface IFoo
{
	[OperationContract]
	string Echo (string msg);
}

/* results
$ ./server.exe
Hit [CR] key to close ... // run client from another terminal
0
True
*/