Loading data from a remote app

I have a method which loads data from a remote app (send TCP request and parse response). Now, I have a simple class for sending a TCP request:

public class PremieraTcpClient
    {
        public PremieraTcpClient()
        {
            QueryItems = new NameValueCollection();
            int port;
            int.TryParse(ConfigurationManager.AppSettings["PremieraPort"], out port);
            Port = port;
            ServerIp = ConfigurationManager.AppSettings["PremieraServerIp"];
            ServiceId = ConfigurationManager.AppSettings["PremieraServiceId"];
        }
        public NameValueCollection QueryItems { get; set; }

        private int Port { get; set; }

        private string ServerIp { get; set; }

        private string ServiceId { get; set; }

        private string ReadyQuery { get; set; }

        public string SendQuery()
        {            
            StringBuilder parameters = new StringBuilder();

            //...
            // build query for request
            //...
            ReadyQuery = parameters.ToString();            
            return Connect();            
        }

        private string Connect()
        {
            string responseData;

            try
            {
                TcpClient client = new TcpClient(ServerIp, Port);
                client.ReceiveBufferSize = Int32.MaxValue;

                Byte[] data = Encoding.GetEncoding(1251).GetBytes(ReadyQuery);

                NetworkStream stream = client.GetStream();

                // send data
                stream.Write(data, 0, data.Length);

                var sizeBuffer = new byte[10];

                stream.Read(sizeBuffer, 0, 10);
                var sizeMessage = int.Parse(Encoding.GetEncoding(1251).GetString(sizeBuffer, 0, 10));

                 data = new Byte[sizeMessage];

                var readSoFar = 0;
                //read data
                while (readSoFar < sizeMessage)
                {
                    readSoFar += stream.Read(data, readSoFar, data.Length - readSoFar);
                }

                responseData = Encoding.GetEncoding(1251).GetString(data, 0, data.Length);                
                responseData = responseData.TrimStart('&');               
                stream.Close();
                client.Close();
                return responseData;
            }
            catch (ArgumentNullException e)
            {
                //return responseData = string.Format("ArgumentNullException: {0}", e);
            }
            catch (SocketException e)
            {
                //return responseData = string.Format("SocketException: {0}", e);
            }
            return string.Empty;
        }    
    }

This is method for load data:

 private static void GetUpdatesFromPremiera()
        {
            Debug.WriteLine(DateTime.Now + ":GetUpdatesFromPremiera");

            PremieraTcpClient client = new PremieraTcpClient();
            client.QueryItems.Add("QueryCode", QueryCode.GetUpdates.ToString());
            client.QueryItems.Add("ListType", "Movie;Hall;Session;Place;Delete");
            client.QueryItems.Add("Updates", _lastUpdateId);
            _lastUpdateId = String.Empty;
            var response = client.SendQuery();

            // here parse response
            //...
        }

This code works fine. But, now I have to load data from two remote app (tomorrow may be three).

The simple solution is to iterate through all remote apps:

private static void GetUpdatesFromPremiera()
{
   foreach(var remoteApp in listRemoteApp)
   {
        PremieraTcpClient client = new PremieraTcpClient();
        // here assigned different properties
        var response = client.SendQuery();
   }
}

Is there is a better way of doing it? Also, each time a connection is established, I think it impacts performance greatly.