diff --git a/src/api2/admin/datastore/backup.rs b/src/api2/admin/datastore/backup.rs
index 67e726f8..9f1ed329 100644
--- a/src/api2/admin/datastore/backup.rs
+++ b/src/api2/admin/datastore/backup.rs
@@ -103,6 +103,9 @@ fn upgrade_to_backup_protocol(
 
                 let mut http = hyper::server::conn::Http::new();
                 http.http2_only(true);
+                // increase window size: todo - find optiomal size
+                http.http2_initial_stream_window_size( (1 << 31) - 2);
+                http.http2_initial_connection_window_size( (1 << 31) - 2);
 
                 http.serve_connection(conn, service)
                     .map_err(Error::from)
@@ -174,6 +177,10 @@ fn backup_api() -> Router {
                     )
                 )
         )
+        .subdir(
+            "speedtest", Router::new()
+                .upload(api_method_upload_speedtest())
+        )
         .subdir("test1", test1)
         .subdir("test2", test2)
         .list_subdirs();
diff --git a/src/api2/admin/datastore/backup/upload_chunk.rs b/src/api2/admin/datastore/backup/upload_chunk.rs
index 0507809b..3ac02ee9 100644
--- a/src/api2/admin/datastore/backup/upload_chunk.rs
+++ b/src/api2/admin/datastore/backup/upload_chunk.rs
@@ -99,3 +99,41 @@ fn upload_dynamic_chunk(
 
     Ok(Box::new(resp))
 }
+
+pub fn api_method_upload_speedtest() -> ApiAsyncMethod {
+    ApiAsyncMethod::new(
+        upload_speedtest,
+        ObjectSchema::new("Test uploadf speed.")
+    )
+}
+
+fn upload_speedtest(
+    _parts: Parts,
+    req_body: Body,
+    param: Value,
+    _info: &ApiAsyncMethod,
+    rpcenv: Box<RpcEnvironment>,
+) -> Result<BoxFut, Error> {
+
+    let resp = req_body
+        .map_err(Error::from)
+        .fold(0, |size: usize, chunk| -> Result<usize, Error> {
+            let sum = size + chunk.len();
+            //println!("UPLOAD {} bytes, sum {}", chunk.len(), sum);
+            Ok(sum)
+        })
+        .then(move |result| {
+            match result {
+                Ok(size) => {
+                    println!("UPLOAD END {} bytes", size);
+                }
+                Err(err) => {
+                    println!("Upload error: {}", err);
+                }
+            }
+            let env: &BackupEnvironment = rpcenv.as_ref();
+            Ok(env.format_response(Ok(Value::Null)))
+        });
+
+    Ok(Box::new(resp))
+}
diff --git a/src/bin/upload-speed.rs b/src/bin/upload-speed.rs
new file mode 100644
index 00000000..d22c66a2
--- /dev/null
+++ b/src/bin/upload-speed.rs
@@ -0,0 +1,43 @@
+use failure::*;
+use futures::*;
+use serde_json::json;
+
+use proxmox_backup::client::*;
+
+fn upload_speed() -> Result<usize, Error> {
+
+    let host = "localhost";
+    let datastore = "store2";
+
+    let username = "root@pam";
+
+    let mut client = HttpClient::new(host, username)?;
+
+    let param = json!({"backup-type": "host", "backup-id": "speedtest" });
+    let upgrade = client.h2upgrade(&format!("/api2/json/admin/datastore/{}/backup", datastore), Some(param));
+
+    let res = upgrade.and_then(|h2| {
+        println!("start upload speed test");
+        h2.upload_speedtest()
+    }).wait()?;
+
+    Ok(res)
+}
+
+fn main()  {
+
+    let mut rt = tokio::runtime::Runtime::new().unwrap();
+
+    // should be rt.block_on_all, but this block forever in release builds
+    let _ = rt.block_on(futures::future::lazy(move || -> Result<(), ()> {
+        match upload_speed() {
+            Ok(mbs) => {
+                println!("average upload speed: {} MB/s", mbs);
+            }
+            Err(err) => {
+                eprintln!("ERROR: {}", err);
+            }
+        }
+        Ok(())
+    }));
+}
diff --git a/src/client/http_client.rs b/src/client/http_client.rs
index c27d5932..3abae83c 100644
--- a/src/client/http_client.rs
+++ b/src/client/http_client.rs
@@ -153,10 +153,14 @@ impl HttpClient {
         builder.danger_accept_invalid_certs(true);
         let tlsconnector = builder.build().unwrap();
         let mut httpc = hyper::client::HttpConnector::new(1);
+        httpc.set_nodelay(true); // important!
         httpc.enforce_http(false); // we want https...
         let mut https = hyper_tls::HttpsConnector::from((httpc, tlsconnector));
         https.https_only(true); // force it!
-        Client::builder().build::<_, Body>(https)
+        Client::builder()
+        //.http2_initial_stream_window_size( (1 << 31) - 2)
+        //.http2_initial_connection_window_size( (1 << 31) - 2)
+            .build::<_, Body>(https)
     }
 
     pub fn request(&self, mut req: Request<Body>) -> impl Future<Item=Value, Error=Error>  {
@@ -425,6 +429,49 @@ impl H2Client {
             })
     }
 
+    pub fn upload_speedtest(&self) -> impl Future<Item=usize, Error=Error> {
+
+        self.h2.clone()
+            .ready()
+            .map_err(Error::from)
+            .and_then(move |mut send_request| {
+
+                let mut data = vec![];
+                // generate pseudo random byte sequence
+                for i in 0..1024*1024 {
+                    for j in 0..4 {
+                        let byte = ((i >> (j<<3))&0xff) as u8;
+                        data.push(byte);
+                    }
+                }
+
+                let item_len = data.len();
+                let repeat = 100;
+
+                let start = std::time::SystemTime::now();
+
+                futures::stream::repeat(data)
+                    .take(repeat)
+                    .for_each(move |data| {
+                        let request = Self::request_builder("localhost", "POST", "speedtest", None).unwrap();
+                        let (response, stream) = send_request.send_request(request, false).unwrap();
+                        println!("send test data ({} bytes)", data.len());
+                        PipeToSendStream::new(bytes::Bytes::from(data), stream)
+                            .and_then(|_| {
+                                response
+                                    .map_err(Error::from)
+                                    .and_then(Self::h2api_response)
+                                    .and_then(|_| Ok(()))
+                            })
+                    })
+                    .and_then(move |_| {
+                        let speed = ((item_len*1000000*(repeat as usize))/(1024*1024))/(start.elapsed()?.as_micros() as usize);
+                        println!("time per request: {} microseconds", (start.elapsed()?.as_micros())/(repeat as u128));
+                        Ok(speed)
+                    })
+            })
+    }
+
     fn request(
         &self,
         request: Request<()>,
diff --git a/src/client/pipe_to_stream.rs b/src/client/pipe_to_stream.rs
index 14c34be7..4a972f29 100644
--- a/src/client/pipe_to_stream.rs
+++ b/src/client/pipe_to_stream.rs
@@ -29,9 +29,9 @@ impl Future for PipeToSendStream {
     fn poll(&mut self) -> Poll<Self::Item, Self::Error> {
         loop {
             if self.data != None {
-                // we don't have the next chunk of data yet, so just reserve 1 byte to make
-                // sure there's some capacity available. h2 will handle the capacity management
-                // for the actual body chunk.
+                // just reserve 1 byte to make sure there's some
+                // capacity available. h2 will handle the capacity
+                // management for the actual body chunk.
                 self.body_tx.reserve_capacity(1);
 
                 if self.body_tx.capacity() == 0 {