webapi.owinSelfHost file download speed is slow

When using the webapi.owinSelfHost library to create a web server, the download speed of files from other computers through the server is very slow. Why is that? My network is 10GE, and the normal transmission speed can reach 1.4G/s. I wrote a webapi program and a client with .net 6 by myself. The test speed can also reach 1.4G/s. Below is the code of rauncing server

    public class RestServer
    {
        internal static List<Type> Controllers = new();
        public static void Register<T>() where T : ApiController
        {
            if (Controllers.IndexOf(typeof(T)) == -1)
            {
                Controllers.Add(typeof(T));
            }
        }
        public static void UnRegister<T>() where T : ApiController
        {
            Controllers.Remove(typeof(T));
        }

        public static void Run(string hostName = "localhost", int port = 37701)
        {
            if (hostName.StartsWith("http"))
            {
                WebApp.Start<RestServer>(hostName);
            }
            else
            {
                WebApp.Start<RestServer>($"http://{hostName}:{port}");
            }

        }
        // This code configures Web API. The Startup class is specified as a type
        // parameter in the WebApp.Start method.
        public void Configuration(IAppBuilder appBuilder)
        {
            // Configure Web API for self-host. 
            HttpConfiguration config = new HttpConfiguration();
            config.Routes.MapHttpRoute(
                name: "DefaultApi",
                routeTemplate: "api/{controller}/{id}",
                defaults: new { id = RouteParameter.Optional }
            );
            config.Services.Replace(typeof(IHttpControllerTypeResolver), new HttpControllerTypeResolverWithRegister());
            appBuilder.UseWebApi(config);

        }
    }
 public class BigDataController : IHttpActionResult
    {
        public override Task<IRestResult> Get(string id = null)
        {
            return Task.Run(() =>
            {
                try
                {
                    Program.bigfile.Position = 0;
                    return BuildStream(Program.bigfile);
                }
                catch (Exception ex)
                {
                    Console.WriteLine(ex.GetBaseException().ToString());
                    throw;
                }

            });
        }
    }
    class StreamResult : IHttpActionResult
    {
        Stream _value;
        HttpRequestMessage _request;

        public StreamResult(Stream value, HttpRequestMessage request)
        {
            _value = value;
            _request = request;
        }
        public Task<HttpResponseMessage> ExecuteAsync(CancellationToken cancellationToken)
        {
            var response = new HttpResponseMessage();
            response.RequestMessage = _request;
            if (_value is null)
            {
                response.StatusCode = System.Net.HttpStatusCode.NoContent;
            }
            else
            {
                _value.Position = 0;
                response.Content = new System.Net.Http.StreamContent(_value);
                response.Content.Headers.ContentType=new MediaTypeHeaderValue("application/octet-stream");
            }
            //response.Headers.Add("Content-Type", "application/octet-stream");
            return Task.FromResult(response);
        }
    }

http response headers and body are same as the other webapi application response headers of owin application Hypertext Transfer Protocol HTTP/1.1 200 OK\r\n Content-Length: 165955581\r\n Content-Type: application/octet-stream\r\n Server: Microsoft-HTTPAPI/2.0\r\n Date: Sat, 16 Sep 2023 08:58:37 GMT\r\n \r\n [HTTP response 1/1] [Time since request: 20.571075000 seconds] [Request in frame: 98824] [Request URI: http://10.0.10.100:37701/api/BigData/122] File Data: 165955581 bytes

response headers of webapi application Hypertext Transfer Protocol HTTP/1.1 200 OK\r\n Content-Length: 129549096\r\n Content-Type: application/octet-stream\r\n Date: Sat, 16 Sep 2023 08:57:32 GMT\r\n Server: Kestrel\r\n Content-Disposition: attachment; filename=bigdata; filename*=UTF-8''bigdata\r\n \r\n [HTTP response 1/1] [Time since request: 0.533893000 seconds] [Request in frame: 208] [Request URI: http://10.0.10.100:5156/w] File Data: 129549096 bytes

The Tcp window size and scaling factor are same, the TCP segment data of both are different, as flowing owin application Transmission Control Protocol, Src Port: 37701, Dst Port: 49706, Seq: 165955151, Ack: 129, Len: 585 Source Port: 37701 Destination Port: 49706 [Stream index: 3] [Conversation completeness: Complete, WITH_DATA (31)] [TCP Segment Len: 585] Sequence Number: 165955151 (relative sequence number) Sequence Number (raw): 2754326255 [Next Sequence Number: 165955736 (relative sequence number)] Acknowledgment Number: 129 (relative ack number) Acknowledgment number (raw): 3724955552 0101 .... = Header Length: 20 bytes (5) Flags: 0x018 (PSH, ACK) Window: 8212 [Calculated window size: 2102272] [Window size scaling factor: 256] Checksum: 0x2b2c [unverified] [Checksum Status: Unverified] Urgent Pointer: 0 [Timestamps] [SEQ/ACK analysis] TCP payload (585 bytes) TCP segment data (585 bytes)

webapi application Transmission Control Protocol, Src Port: 5156, Dst Port: 49705, Seq: 129548192, Ack: 44, Len: 1122 Source Port: 5156 Destination Port: 49705 [Stream index: 1] [Conversation completeness: Complete, WITH_DATA (47)] [TCP Segment Len: 1122] Sequence Number: 129548192 (relative sequence number) Sequence Number (raw): 1706970176 [Next Sequence Number: 129549314 (relative sequence number)] Acknowledgment Number: 44 (relative ack number) Acknowledgment number (raw): 3207951358 0101 .... = Header Length: 20 bytes (5) Flags: 0x018 (PSH, ACK) Window: 8212 [Calculated window size: 2102272] [Window size scaling factor: 256] Checksum: 0x2d45 [unverified] [Checksum Status: Unverified] Urgent Pointer: 0 [Timestamps] [SEQ/ACK analysis] TCP payload (1122 bytes) TCP segment data (1122 bytes)

Can tell me how to solve this problem?

aspnet / AspNetWebStack

webapi.owinSelfHost file download speed is slow #409