客户端/服务器与 StreamSockets 的通信 - 客户端无限等待

根据MSDN，我有以下代码来创建与TCP/IP StreamSockets的客户端/服务器通信。

服务器：

public async void Start(int port)
{
    try
    {
        //Create a StreamSocketListener to start listening for TCP connections.
        StreamSocketListener socketListener = new StreamSocketListener();
        //Hook up an event handler to call when connections are received.
        socketListener.ConnectionReceived += SocketListener_ConnectionReceived;
        //Start listening for incoming TCP connections on the specified port. You can specify any port that's not currently in use.
        await socketListener.BindServiceNameAsync(port.ToString());
    }
    catch (Exception ex)
    {
        Debug.WriteLine("SocketServer could not start. " + ex.ToString());
    }
}
private async void SocketListener_ConnectionReceived(StreamSocketListener sender, StreamSocketListenerConnectionReceivedEventArgs args)
{
    try
    {
        string request;
        //Read line from the remote client.
        using (Stream inStream = args.Socket.InputStream.AsStreamForRead())
        {
            using (StreamReader reader = new StreamReader(inStream))
            {
                request = await reader.ReadLineAsync();
            }
        }
        // Process command and get response
        SocketResponse response = ProcessRequest(request);
        string responseString = JsonHelper.ToJson<SocketResponse>(response);
        //Send the line back to the remote client.
        using (Stream outStream = args.Socket.OutputStream.AsStreamForWrite())
        {
            using (StreamWriter writer = new StreamWriter(outStream))
            {
                await writer.WriteLineAsync(responseString);
                await writer.FlushAsync();
            }
        }
    }
    catch(Exception ex)
    {
        Debug.WriteLine("SocketListener failed." + ex.ToString());
    }
}

客户：

private async Task Start(int responseTimeout)
{
    CancellationTokenSource cts = new CancellationTokenSource();
    try
    {
        cts.CancelAfter(responseTimeout);
        //Create the StreamSocket and establish a connection to the echo server.
        socket = new StreamSocket();
        //The server hostname that we will be establishing a connection to. We will be running the server and client locally,
        //so we will use localhost as the hostname.
        HostName serverHost = new HostName(hostName);
        //Every protocol typically has a standard port number. For example HTTP is typically 80, FTP is 20 and 21, etc.
        //For the echo server/client application we will use a random port 1337.
        string serverPort = port.ToString();
        await socket.ConnectAsync(serverHost, serverPort).AsTask(cts.Token);
    }
    catch
    {
        socket.Dispose();
    }
}
public async Task<SocketResponse> SendCommand(SocketCommand command, int responseTimeout = 2000)
{
    // Connect to socket first
    await Start(responseTimeout);
    //Write data to the echo server.
    using (Stream streamOut = socket.OutputStream.AsStreamForWrite())
    {
        using (StreamWriter writer = new StreamWriter(streamOut))
        {
            // Serialize command to json and send
            string request = JsonHelper.ToJson<SocketCommand>(command);
            await writer.WriteLineAsync(request);
            await writer.FlushAsync();
        }
    }
    //Read data from the echo server.
    using (Stream streamIn = socket.InputStream.AsStreamForRead())
    {
        using (StreamReader reader = new StreamReader(streamIn))
        {
            string responseString = await reader.ReadLineAsync();
            return JsonHelper.FromJson<SocketResponse>(responseString);
        }
    }
}

我的代码遇到了两个问题：

1. 我必须在每个请求之前从客户端建立连接。原因是什么？
2. 当我从服务器发送更大的响应（字符串为 3kb）时，客户端无限等待响应，但服务器响应很快。此外，如果服务器关闭，则客户端会读取响应。这是怎么回事？