套接字编程能够从 telnet 获取响应，但不能从 c# 代码获取响应

我能够通过telnet连接服务器并通过telnet接收响应，但是如果我通过代码做同样的事情，我无法得到它。我非常确定我的代码是正确的，因为我已经通过在本地创建客户端和服务器对其进行了测试。

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Net.Sockets;
using System.Configuration;
namespace ClientSocket
{
    public partial class Client : Form
    {
        System.Net.Sockets.TcpClient clientSocket = new System.Net.Sockets.TcpClient();
        NetworkStream serverStream; 
        public Client()
        {
            InitializeComponent();
        }
        private void Client_Load(object sender, EventArgs e)
        {
            msg("Client Started");
            //clientSocket.Connect(ConfigurationManager.AppSettings["ip"].ToString(), Convert.ToInt16(ConfigurationManager.AppSettings["port"]));
            clientSocket.Connect("172.29.29.6", 7506);
            label1.Text = "Client Socket Program - Server Connected ...";
        }
        public void msg(string mesg)
        {
            textBox1.Text = textBox1.Text + Environment.NewLine + " >> " + mesg;
        }
        private void button1_Click(object sender, EventArgs e)
        {
            NetworkStream serverStream = clientSocket.GetStream();
            byte[] outStream = System.Text.Encoding.ASCII.GetBytes(txtMessage.Text);
            serverStream.Write(outStream, 0, outStream.Length);
            serverStream.Flush();
            byte[] inStream = new byte[1000768];
            serverStream.Read(inStream, 0, (int)clientSocket.ReceiveBufferSize);
            //serverStream.Read(inStream, 0, 1000768);
            string returndata = System.Text.Encoding.ASCII.GetString(inStream);
            msg("Data from Server : " + returndata);
        }
    }
}