Silverlight 4 with (HTTP) Duplex and SQL Notifications

using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.Serialization;
using System.ServiceModel;
using System.ServiceModel.Web;
using System.Text;
using SLDuplexDependency.Web.Model;

namespace SLDuplexDependency.Web
{
    [ServiceContract(Namespace = "Silverlight", CallbackContract = typeof(IDuplexServiceClient))]
    public interface IDuplexService
    {
        [OperationContract(IsOneWay = true)]
        void Connect(string id);
    }

    [ServiceContract]
    public interface IDuplexServiceClient
    {
        [OperationContract(IsOneWay = true)]
        void SendTrainDelay(List<Author> delayInfo);
    }
}