C#

using System;
using System.ServiceModel;

namespace MessagingSample
{
    [ServiceContract]
    public interface ISampleContract
    {
        [OperationContract(IsOneWay = true)]
        void StartDoingSomething(string someText, SampleClient client);
    }

    [ServiceBehavior]
    public class SampleClient
    {
        private ISampleContract workerService;

        public void StartClient(string server)
        {
            // Init the service instance
            EndpointAddress endpointAddress = new EndpointAddress(
                new Uri(string.Format(@"net.msmq://{0}/private/SampleQueue", server)));

            NetMsmqBinding clientBinding = new NetMsmqBinding();
            clientBinding.Security.Transport.MsmqAuthenticationMode = MsmqAuthenticationMode.None;
            clientBinding.Security.Transport.MsmqProtectionLevel = System.Net.Security.ProtectionLevel.None;

            ChannelFactory<ISampleContract> channelFactory =
                new ChannelFactory<ISampleContract>(clientBinding, endpointAddress);
            workerService = channelFactory.CreateChannel();

        }

        public void StopClient()
        {
            if (workerService != null)
            {
                workerService = null;
            }
        }

        public void StartDoingSomething(string text)
        {
            if (workerService != null)
            {
                workerService.StartDoingSomething(text, this);
            }
        }

        public void DoSomethingElse(string text)
        {
            System.Diagnostics.Debug.WriteLine(text);
        }
    }


    [ServiceBehavior]
    public class SampleServer : ISampleContract
    {
        private ServiceHost serviceHost = null;

        public void StartServer(string server)
        {
            Uri serviceUri = new Uri(string.Format(@"net.msmq://{0}/private/SampleQueue", server));

            NetMsmqBinding serviceBinding = new NetMsmqBinding();
            serviceBinding.Security.Transport.MsmqAuthenticationMode = MsmqAuthenticationMode.None;
            serviceBinding.Security.Transport.MsmqProtectionLevel = System.Net.Security.ProtectionLevel.None;
            serviceBinding.MaxReceivedMessageSize = 1024 * 4096;
            serviceBinding.ReaderQuotas.MaxArrayLength = 1024 * 4096;

            serviceHost = new ServiceHost(typeof(SampleServer));
            serviceHost.AddServiceEndpoint(typeof(ISampleContract), serviceBinding, serviceUri);

            serviceHost.Open();
        }

        public void StopServer()
        {
            if (serviceHost != null)
            {
                serviceHost.Close();
            }
        }

        // ISampleContract Member
        public void StartDoingSomething(string someText, SampleClient client)
        {
            System.Diagnostics.Debug.WriteLine(someText);
            client.DoSomethingElse("Processed: "+ someText);
        }
    }
}