unity的tcp和udp

近来有需求如下：局域网内两个人合作拆装一个东西，比如汽车引擎。于是开始学习socket通信。还好网上这个教程已经很多了，整理了一下自己拿过来用了。
最开始用的是UDP，因为想着客户端A做了什么直接扔给服务器然后服务器再扔给客户端B（反过来也一样）就完事了。
udp客户端和服务器端的基类：

using UnityEngine;

public abstract class BaseUDP : MonoBehaviour {

    public abstract void InitSocket();
    public abstract void SocketSend(string sender);
    public abstract void SocketReceive();
}

服务器端：

using UnityEngine;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Threading;
using LitJson;
using System.Collections.Generic;
using UnityEngine.UI;
public class UDPServer : BaseUDP
{
    /// <summary>
    /// 设置服务器IP
    /// </summary>
    public string ipAddress;
    /// <summary>
    /// 服务器侦听端口
    /// </summary>
    public int ConnectPort;
    /// <summary>
    /// 服务器接收到的消息
    /// </summary>
    public string recvStr=null;
    /// <summary>
    /// 服务器接收到的IP和端口信息，记录下来
    /// </summary>
    private List<EndPoint> mEndPoint = null;
    /// <summary>
    /// 声明套接字
    /// </summary>
    private Socket socket;
    /// <summary>
    /// 客户端地址
    /// </summary>
    private EndPoint clientEnd;
    /// <summary>
    /// 服务器端地址
    /// </summary>
    private IPEndPoint ipEnd;
    /// <summary>
    /// 服务器发送的消息
    /// </summary>
    private string sendStr;
    /// <summary>
    /// 接收和发送消息字节流
    /// </summary>
    byte[] recvData = new byte[1024];
    byte[] sendData = new byte[1024];
    /// <summary>
    /// 接收消息的长度
    /// </summary>
    private int recvLen;
    /// <summary>
    /// 侦听客户端的线程
    /// </summary>
    private Thread connectThread;
    public Text mInfo;
    private Dictionary<string, EndPoint> mClients=new Dictionary<string, EndPoint>();
    //初始化
    public override void InitSocket()
    {
        //用指定的端口和地址初始化IPEndPoint实例
        ipEnd = new IPEndPoint(IPAddress.Parse(ipAddress), ConnectPort);
        //初始化socket（AddressFamily.InterNetwork，指定socket的寻址方案是IPV4）
        //SocketType.Dgram   支持数据报，即最大长度固定（通常很小）的无连接、不可靠消息
        socket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
        socket.Bind(ipEnd);
        //定义客户端
        IPEndPoint sender = new IPEndPoint(IPAddress.Any, 0);
        clientEnd = (EndPoint)sender;
        print("等待连接数据");
        //开启一个线程连接
        connectThread = new Thread(new ThreadStart(SocketReceive));
        connectThread.Start();
    }
    //服务器发送消息
    public override void SocketSend(string sendStr)
    {
        sendData = new byte[1024];
        sendData = Encoding.UTF8.GetBytes(sendStr);
        foreach (var item in mClients)
        {
            if (item.Key!=clientEnd.ToString())
            {
                socket.SendTo(sendData, sendData.Length, SocketFlags.None, item.Value);
                Debug.Log("发送" + sendStr + "给" + item.ToString());
            }
        }
    }
    //服务器接收
    public override void SocketReceive()
    {
        while (true)
        {
            recvData = new byte[1024];
            recvLen = socket.ReceiveFrom(recvData, ref clientEnd);
            recvStr = Encoding.UTF8.GetString(recvData, 0, recvLen);
            Debug.Log("服务器接收到的："+recvStr);
            Debug.Log(clientEnd.ToString());
            if (mClien