C# TCP Socket无法读取医疗设备ACK报文问题求助

• Wireshark可捕获到医疗设备发送的ACK报文，但C# Socket代码无法读取该报文
• 通信流程需等待ACK才能继续，当前因接收超时触发错误：无法建立连接。连接方在一段时间后未正确响应，或连接的主机未响应。
• 除Read方法外其余代码运行正常，可正常发送ACK，但无法接收设备返回的ACK
• 补充测试：使用COM端口数据模拟器发送的ACK能被正常读取，仅医疗设备的ACK无法读取
• 曾查阅相关技术资料但未找到可行方案，有人建议使用PcapDotNet但不知如何实现

相关代码 #

using System;
using System.Text;
using System.Net.Sockets;

namespace myCom
{
    public partial class SocketLan
    {
        private Socket oClientSocket;

        public SocketLan(string cIp, int nPort)
        {
            try
            {
                this.oClientSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);

                if (this.Connect(cIp, nPort))
                {
                    this.oClientSocket.SendTimeout = 5000;
                    this.oClientSocket.ReceiveTimeout = 5000;
                }
            }
            catch 
            {
                this.oClientSocket.Close();
            }
        }

        public bool Connect(string cIp, int nPort)
        {
            bool lOk;
            IAsyncResult ar;

            ar = this.oClientSocket.BeginConnect(cIp, nPort, null, null);
            try
            {
                if (!ar.AsyncWaitHandle.WaitOne(TimeSpan.FromSeconds(5), false))
                {
                    throw new TimeoutException();
                }
                this.oClientSocket.EndConnect(ar);
                lOk = true;
            }
            catch
            {
                lOk = false;
            }

            return lOk;
        }

        public string Read(int nRead = 1024)
        {
            string cReturnData = "";
            byte[] InStream;
            int nByte;

            if (this.oClientSocket.Connected)
            {
                InStream = new byte[nRead];

                try
                {
                    nByte = this.oClientSocket.Receive(InStream, 0, nRead, SocketFlags.None);//Here it goes wrong
                    if (nByte > 0)
                    {
                        cReturnData = Encoding.ASCII.GetString(InStream, 0, nByte);
                    }
                }
                catch (Exception ex)
                {
                    cReturnData = "";
                    string cError = ex.Message;//This is the error!
                    return cReturnData;
                }
            }

            return cReturnData;
        }
    }
}

内容的提问来源于stack exchange，提问作者Infoservice