v4.7.1

changelog.md

@@ -1,5 +1,82 @@
 # Changelog
 
+## 2026-03-17 - 4.7.1 - fix(remoteingress-core)
+improve tunnel failure detection and reconnect handling
+
+- Enable TCP keepalive on edge and hub connections to detect silent network failures sooner
+- Trigger immediate reconnect or disconnect when tunnel writer tasks fail instead of waiting for liveness timeouts
+- Prevent active stream counter underflow during concurrent connection cleanup
+
+## 2026-03-16 - 4.7.0 - feat(edge,protocol,test)
+add configurable edge bind address and expand flow-control test coverage
+
+- adds an optional bindAddress configuration for edge TCP listeners, defaulting to 0.0.0.0 when not provided
+- passes bindAddress through the TypeScript edge client and Rust edge runtime so local test setups can bind to localhost
+- adds protocol unit tests for adaptive stream window sizing and window update frame encoding/decoding
+- introduces end-to-end flow-control tests and updates the test script to build before running tests
+
+## 2026-03-16 - 4.6.1 - fix(remoteingress-core)
+avoid spurious tunnel disconnect events and increase control channel capacity
+
+- Emit TunnelDisconnected only after an established connection is actually lost, preventing false disconnect events during failed reconnect attempts.
+- Increase edge and hub control-channel buffer sizes from 64 to 256 to better prioritize control frames under load.
+
+## 2026-03-16 - 4.6.0 - feat(remoteingress-core)
+add adaptive per-stream flow control based on active stream counts
+
+- Track active stream counts on edge and hub connections to size per-stream flow control windows dynamically.
+- Cap WINDOW_UPDATE increments and read sizes to the adaptive window so bandwidth is shared more evenly across concurrent streams.
+- Apply the adaptive logic to both upload and download paths on edge and hub stream handlers.
+
+## 2026-03-16 - 4.5.12 - fix(remoteingress-core)
+improve tunnel liveness handling and enable TCP keepalive for accepted client sockets
+
+- Avoid disconnecting edges when PING or PONG frames cannot be queued because the control channel is temporarily full.
+- Enable TCP_NODELAY and TCP keepalive on accepted client connections to help detect stale or dropped clients.
+
+## 2026-03-16 - 4.5.11 - fix(repo)
+no changes to commit
+
+
+## 2026-03-16 - 4.5.10 - fix(remoteingress-core)
+guard zero-window reads to avoid false EOF handling on stalled streams
+
+- Prevent upload and download loops from calling read on an empty buffer when flow-control window remains at 0 after stall timeout
+- Log a warning and close the affected stream instead of misinterpreting Ok(0) as end-of-file
+
+## 2026-03-16 - 4.5.9 - fix(remoteingress-core)
+delay stream close until downstream response draining finishes to prevent truncated transfers
+
+- Waits for the hub-to-client download task to finish before sending the stream CLOSE frame
+- Prevents upstream reads from being cancelled mid-response during asymmetric transfers such as git fetch
+- Retains the existing timeout so stalled downloads still clean up safely
+
+## 2026-03-16 - 4.5.8 - fix(remoteingress-core)
+ensure upstream writes cancel promptly and reliably deliver CLOSE_BACK frames
+
+- listen for stream cancellation while waiting on upstream write timeouts so FRAME_CLOSE does not block for up to 60 seconds
+- replace try_send with send().await when emitting CLOSE_BACK frames to avoid silently dropping close notifications when the data channel is full
+
+## 2026-03-16 - 4.5.7 - fix(remoteingress-core)
+improve tunnel reconnect and frame write efficiency
+
+- Reuse the TLS connector across edge reconnections to preserve session resumption state and reduce reconnect latency.
+- Buffer hub and edge frame writes to coalesce small control and data frames into fewer TLS records and syscalls while still flushing each frame promptly.
+
+## 2026-03-16 - 4.5.6 - fix(remoteingress-core)
+disable Nagle's algorithm on edge, hub, and upstream TCP sockets to reduce control-frame latency
+
+- Enable TCP_NODELAY on the edge connection to the hub for faster PING/PONG and WINDOW_UPDATE delivery
+- Apply TCP_NODELAY on accepted hub streams before TLS handling
+- Enable TCP_NODELAY on SmartProxy upstream connections before sending the PROXY header
+
+## 2026-03-16 - 4.5.5 - fix(remoteingress-core)
+wait for hub-to-client draining before cleanup and reliably send close frames
+
+- switch CLOSE frame delivery on the data channel from try_send to send().await to avoid dropping it when the channel is full
+- delay stream cleanup until the hub-to-client task finishes or times out so large downstream responses continue after upload EOF
+- add a bounded 5-minute wait for download draining to prevent premature termination of asymmetric transfers such as git fetch
+
 ## 2026-03-15 - 4.5.4 - fix(remoteingress-core)
 preserve stream close ordering and add flow-control stall timeouts
 

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@serve.zone/remoteingress",
-  "version": "4.5.4",
+  "version": "4.7.1",
   "private": false,
   "description": "Edge ingress tunnel for DcRouter - accepts incoming TCP connections at network edge and tunnels them to DcRouter SmartProxy preserving client IP via PROXY protocol v1.",
   "main": "dist_ts/index.js",
@@ -9,7 +9,7 @@
   "author": "Task Venture Capital GmbH",
   "license": "MIT",
   "scripts": {
-    "test": "(tstest test/ --verbose --logfile --timeout 60)",
+    "test": "(pnpm run build && tstest test/ --verbose --logfile --timeout 60)",
     "build": "(tsbuild tsfolders --allowimplicitany && tsrust)",
     "buildDocs": "(tsdoc)"
   },

rust/Cargo.lock

@@ -558,6 +558,7 @@ dependencies = [
  "rustls-pemfile",
  "serde",
  "serde_json",
+ "socket2 0.5.10",
  "tokio",
  "tokio-rustls",
  "tokio-util",
@@ -701,6 +702,16 @@ version = "1.15.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "67b1b7a3b5fe4f1376887184045fcf45c69e92af734b7aaddc05fb777b6fbd03"
 
+[[package]]
+name = "socket2"
+version = "0.5.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e22376abed350d73dd1cd119b57ffccad95b4e585a7cda43e286245ce23c0678"
+dependencies = [
+ "libc",
+ "windows-sys 0.52.0",
+]
+
 [[package]]
 name = "socket2"
 version = "0.6.2"
@@ -765,7 +776,7 @@ dependencies = [
  "parking_lot",
  "pin-project-lite",
  "signal-hook-registry",
- "socket2",
+ "socket2 0.6.2",
  "tokio-macros",
  "windows-sys 0.61.2",
 ]

rust/crates/remoteingress-core/Cargo.toml

@@ -14,3 +14,4 @@ serde_json = "1"
 log = "0.4"
 rustls-pemfile = "2"
 tokio-util = "0.7"
+socket2 = "0.5"

rust/crates/remoteingress-core/src/edge.rs

@@ -32,6 +32,10 @@ pub struct EdgeConfig {
     pub hub_port: u16,
     pub edge_id: String,
     pub secret: String,
+    /// Optional bind address for TCP listeners (defaults to "0.0.0.0").
+    /// Useful for testing on localhost where edge and upstream share the same machine.
+    #[serde(default)]
+    pub bind_address: Option<String>,
 }
 
 /// Handshake config received from hub after authentication.
@@ -194,6 +198,14 @@ async fn edge_main_loop(
     let mut backoff_ms: u64 = 1000;
     let max_backoff_ms: u64 = 30000;
 
+    // Build TLS config ONCE outside the reconnect loop — preserves session
+    // cache across reconnections for TLS session resumption (saves 1 RTT).
+    let tls_config = rustls::ClientConfig::builder()
+        .dangerous()
+        .with_custom_certificate_verifier(Arc::new(NoCertVerifier))
+        .with_no_client_auth();
+    let connector = TlsConnector::from(Arc::new(tls_config));
+
     loop {
         // Create a per-connection child token
         let connection_token = cancel_token.child_token();
@@ -209,6 +221,7 @@ async fn edge_main_loop(
             &listen_ports,
             &mut shutdown_rx,
             &connection_token,
+            &connector,
         )
         .await;
 
@@ -223,7 +236,11 @@ async fn edge_main_loop(
         }
 
         *connected.write().await = false;
-        let _ = event_tx.try_send(EdgeEvent::TunnelDisconnected);
+        // Only emit disconnect event on actual disconnection, not on failed reconnects.
+        // Failed reconnects never reach line 335 (handshake success), so was_connected is false.
+        if was_connected {
+            let _ = event_tx.try_send(EdgeEvent::TunnelDisconnected);
+        }
         active_streams.store(0, Ordering::Relaxed);
         // Reset stream ID counter for next connection cycle
         next_stream_id.store(1, Ordering::Relaxed);
@@ -259,18 +276,23 @@ async fn connect_to_hub_and_run(
     listen_ports: &Arc<RwLock<Vec<u16>>>,
     shutdown_rx: &mut mpsc::Receiver<()>,
     connection_token: &CancellationToken,
+    connector: &TlsConnector,
 ) -> EdgeLoopResult {
-    // Build TLS connector that skips cert verification (auth is via secret)
-    let tls_config = rustls::ClientConfig::builder()
-        .dangerous()
-        .with_custom_certificate_verifier(Arc::new(NoCertVerifier))
-        .with_no_client_auth();
-
-    let connector = TlsConnector::from(Arc::new(tls_config));
 
     let addr = format!("{}:{}", config.hub_host, config.hub_port);
     let tcp = match TcpStream::connect(&addr).await {
-        Ok(s) => s,
+        Ok(s) => {
+            // Disable Nagle's algorithm for low-latency control frames (PING/PONG, WINDOW_UPDATE)
+            let _ = s.set_nodelay(true);
+            // TCP keepalive detects silent network failures (NAT timeout, path change)
+            // faster than the 45s application-level liveness timeout.
+            let ka = socket2::TcpKeepalive::new()
+                .with_time(Duration::from_secs(30));
+            #[cfg(target_os = "linux")]
+            let ka = ka.with_interval(Duration::from_secs(10));
+            let _ = socket2::SockRef::from(&s).set_tcp_keepalive(&ka);
+            s
+        }
         Err(e) => {
             log::error!("Failed to connect to hub at {}: {}", addr, e);
             return EdgeLoopResult::Reconnect;
@@ -368,21 +390,27 @@ async fn connect_to_hub_and_run(
 
     // QoS dual-channel tunnel writer: control frames (PONG/WINDOW_UPDATE/CLOSE/OPEN)
     // have priority over data frames (DATA). Prevents PING starvation under load.
-    let (tunnel_ctrl_tx, mut tunnel_ctrl_rx) = mpsc::channel::<Vec<u8>>(64);
+    let (tunnel_ctrl_tx, mut tunnel_ctrl_rx) = mpsc::channel::<Vec<u8>>(256);
     let (tunnel_data_tx, mut tunnel_data_rx) = mpsc::channel::<Vec<u8>>(4096);
     // Legacy alias — control channel for PONG, CLOSE, WINDOW_UPDATE, OPEN
     let tunnel_writer_tx = tunnel_ctrl_tx.clone();
     let tw_token = connection_token.clone();
+    // Oneshot to signal the reader loop when the writer dies from a write error.
+    // This avoids the 45s liveness timeout delay when the tunnel is already dead.
+    let (writer_dead_tx, mut writer_dead_rx) = tokio::sync::oneshot::channel::<()>();
     let tunnel_writer_handle = tokio::spawn(async move {
+        // BufWriter coalesces small writes (frame headers, control frames) into fewer
+        // TLS records and syscalls. Flushed after each frame to avoid holding data.
+        let mut writer = tokio::io::BufWriter::with_capacity(65536, write_half);
+        let mut write_error = false;
         loop {
             tokio::select! {
                 biased; // control frames always take priority over data
                 ctrl = tunnel_ctrl_rx.recv() => {
                     match ctrl {
                         Some(frame_data) => {
-                            if write_half.write_all(&frame_data).await.is_err() {
-                                break;
-                            }
+                            if writer.write_all(&frame_data).await.is_err() { write_error = true; break; }
+                            if writer.flush().await.is_err() { write_error = true; break; }
                         }
                         None => break,
                     }
@@ -390,9 +418,8 @@ async fn connect_to_hub_and_run(
                 data = tunnel_data_rx.recv() => {
                     match data {
                         Some(frame_data) => {
-                            if write_half.write_all(&frame_data).await.is_err() {
-                                break;
-                            }
+                            if writer.write_all(&frame_data).await.is_err() { write_error = true; break; }
+                            if writer.flush().await.is_err() { write_error = true; break; }
                         }
                         None => break,
                     }
@@ -400,10 +427,15 @@ async fn connect_to_hub_and_run(
                 _ = tw_token.cancelled() => break,
             }
         }
+        if write_error {
+            log::error!("Tunnel writer failed, signalling reader for fast reconnect");
+            let _ = writer_dead_tx.send(());
+        }
     });
 
     // Start TCP listeners for initial ports (hot-reloadable)
     let mut port_listeners: HashMap<u16, JoinHandle<()>> = HashMap::new();
+    let bind_address = config.bind_address.as_deref().unwrap_or("0.0.0.0");
     apply_port_config(
         &handshake.listen_ports,
         &mut port_listeners,
@@ -414,6 +446,7 @@ async fn connect_to_hub_and_run(
         next_stream_id,
         &config.edge_id,
         connection_token,
+        bind_address,
     );
 
     // Heartbeat: liveness timeout detects silent hub failures
@@ -480,14 +513,17 @@ async fn connect_to_hub_and_run(
                                         next_stream_id,
                                         &config.edge_id,
                                         connection_token,
+                                        bind_address,
                                     );
                                 }
                             }
                             FRAME_PING => {
                                 let pong_frame = encode_frame(0, FRAME_PONG, &[]);
                                 if tunnel_writer_tx.try_send(pong_frame).is_err() {
-                                    log::warn!("Failed to send PONG, writer channel full/closed");
-                                    break EdgeLoopResult::Reconnect;
+                                    // Control channel full (WINDOW_UPDATE burst from many streams).
+                                    // DON'T disconnect — the 45s liveness timeout gives margin
+                                    // for the channel to drain and the next PONG to succeed.
+                                    log::warn!("PONG send failed, control channel full — skipping this cycle");
                                 }
                                 log::trace!("Received PING from hub, sent PONG");
                             }
@@ -511,6 +547,10 @@ async fn connect_to_hub_and_run(
                     liveness_timeout_dur.as_secs());
                 break EdgeLoopResult::Reconnect;
             }
+            _ = &mut writer_dead_rx => {
+                log::error!("Tunnel writer died, reconnecting immediately");
+                break EdgeLoopResult::Reconnect;
+            }
             _ = connection_token.cancelled() => {
                 log::info!("Connection cancelled");
                 break EdgeLoopResult::Shutdown;
@@ -543,6 +583,7 @@ fn apply_port_config(
     next_stream_id: &Arc<AtomicU32>,
     edge_id: &str,
     connection_token: &CancellationToken,
+    bind_address: &str,
 ) {
     let new_set: std::collections::HashSet<u16> = new_ports.iter().copied().collect();
     let old_set: std::collections::HashSet<u16> = port_listeners.keys().copied().collect();
@@ -565,8 +606,9 @@ fn apply_port_config(
         let edge_id = edge_id.to_string();
         let port_token = connection_token.child_token();
 
+        let bind_addr = bind_address.to_string();
         let handle = tokio::spawn(async move {
-            let listener = match TcpListener::bind(("0.0.0.0", port)).await {
+            let listener = match TcpListener::bind((bind_addr.as_str(), port)).await {
                 Ok(l) => l,
                 Err(e) => {
                     log::error!("Failed to bind port {}: {}", port, e);
@@ -580,6 +622,15 @@ fn apply_port_config(
                     accept_result = listener.accept() => {
                         match accept_result {
                             Ok((client_stream, client_addr)) => {
+                                // TCP keepalive detects dead clients that disappear without FIN.
+                                // Without this, zombie streams accumulate and never get cleaned up.
+                                let _ = client_stream.set_nodelay(true);
+                                let ka = socket2::TcpKeepalive::new()
+                                    .with_time(Duration::from_secs(60));
+                                #[cfg(target_os = "linux")]
+                                let ka = ka.with_interval(Duration::from_secs(60));
+                                let _ = socket2::SockRef::from(&client_stream).set_tcp_keepalive(&ka);
+
                                 let stream_id = next_stream_id.fetch_add(1, Ordering::Relaxed);
                                 let tunnel_ctrl_tx = tunnel_ctrl_tx.clone();
                                 let tunnel_data_tx = tunnel_data_tx.clone();
@@ -601,9 +652,21 @@ fn apply_port_config(
                                         tunnel_data_tx,
                                         client_writers,
                                         client_token,
+                                        Arc::clone(&active_streams),
                                     )
                                     .await;
-                                    active_streams.fetch_sub(1, Ordering::Relaxed);
+                                    // Saturating decrement: prevent underflow when
+                                    // edge_main_loop's store(0) races with task cleanup.
+                                    loop {
+                                        let current = active_streams.load(Ordering::Relaxed);
+                                        if current == 0 { break; }
+                                        if active_streams.compare_exchange_weak(
+                                            current, current - 1,
+                                            Ordering::Relaxed, Ordering::Relaxed,
+                                        ).is_ok() {
+                                            break;
+                                        }
+                                    }
                                 });
                             }
                             Err(e) => {
@@ -632,6 +695,7 @@ async fn handle_client_connection(
     tunnel_data_tx: mpsc::Sender<Vec<u8>>,
     client_writers: Arc<Mutex<HashMap<u32, EdgeStreamState>>>,
     client_token: CancellationToken,
+    active_streams: Arc<AtomicU32>,
 ) {
     let client_ip = client_addr.ip().to_string();
     let client_port = client_addr.port();
@@ -665,7 +729,8 @@ async fn handle_client_connection(
     // After writing to client TCP, send WINDOW_UPDATE to hub so it can send more
     let hub_to_client_token = client_token.clone();
     let wu_tx = tunnel_ctrl_tx.clone();
-    let hub_to_client = tokio::spawn(async move {
+    let active_streams_h2c = Arc::clone(&active_streams);
+    let mut hub_to_client = tokio::spawn(async move {
         let mut consumed_since_update: u32 = 0;
         loop {
             tokio::select! {
@@ -676,12 +741,20 @@ async fn handle_client_connection(
                             if client_write.write_all(&data).await.is_err() {
                                 break;
                             }
-                            // Track consumption for flow control
+                            // Track consumption for adaptive flow control.
+                            // The increment is capped to the adaptive window so the sender's
+                            // effective window shrinks to match current demand (fewer streams
+                            // = larger window, more streams = smaller window per stream).
                             consumed_since_update += len;
-                            if consumed_since_update >= WINDOW_UPDATE_THRESHOLD {
-                                let frame = encode_window_update(stream_id, FRAME_WINDOW_UPDATE, consumed_since_update);
+                            let adaptive_window = remoteingress_protocol::compute_window_for_stream_count(
+                                active_streams_h2c.load(Ordering::Relaxed),
+                            );
+                            let threshold = adaptive_window / 2;
+                            if consumed_since_update >= threshold {
+                                let increment = consumed_since_update.min(adaptive_window);
+                                let frame = encode_window_update(stream_id, FRAME_WINDOW_UPDATE, increment);
                                 if wu_tx.try_send(frame).is_ok() {
-                                    consumed_since_update = 0;
+                                    consumed_since_update -= increment;
                                 }
                                 // If try_send fails, keep accumulating — retry on next threshold
                             }
@@ -718,9 +791,20 @@ async fn handle_client_connection(
         }
         if client_token.is_cancelled() { break; }
 
-        // Limit read size to available window
+        // Limit read size to available window.
+        // IMPORTANT: if window is 0 (stall timeout fired), we must NOT
+        // read into an empty buffer — read(&mut buf[..0]) returns Ok(0)
+        // which would be falsely interpreted as EOF.
         let w = send_window.load(Ordering::Acquire) as usize;
-        let max_read = w.min(buf.len());
+        if w == 0 {
+            log::warn!("Stream {} upload: window still 0 after stall timeout, closing", stream_id);
+            break;
+        }
+        // Adaptive: cap read to current per-stream target window
+        let adaptive_cap = remoteingress_protocol::compute_window_for_stream_count(
+            active_streams.load(Ordering::Relaxed),
+        ) as usize;
+        let max_read = w.min(buf.len()).min(adaptive_cap);
 
         tokio::select! {
             read_result = client_read.read(&mut buf[..max_read]) => {
@@ -741,18 +825,29 @@ async fn handle_client_connection(
         }
     }
 
-    // Send CLOSE frame via DATA channel (must arrive AFTER last DATA for this stream)
+    // Wait for the download task (hub → client) to finish BEFORE sending CLOSE.
+    // Upload EOF (client done sending) does NOT mean the response is done.
+    // For asymmetric transfers like git fetch (small request, large response),
+    // the response is still streaming when the upload finishes.
+    // Sending CLOSE before the response finishes would cause the hub to cancel
+    // the upstream reader mid-response, truncating the data.
+    let _ = tokio::time::timeout(
+        Duration::from_secs(300),  // 5 min max wait for download to finish
+        &mut hub_to_client,
+    ).await;
+
+    // NOW send CLOSE — the response has been fully delivered (or timed out).
     if !client_token.is_cancelled() {
         let close_frame = encode_frame(stream_id, FRAME_CLOSE, &[]);
-        let _ = tunnel_data_tx.try_send(close_frame);
+        let _ = tunnel_data_tx.send(close_frame).await;
     }
 
-    // Cleanup
+    // Clean up
     {
         let mut writers = client_writers.lock().await;
         writers.remove(&stream_id);
     }
-    hub_to_client.abort();
+    hub_to_client.abort(); // No-op if already finished; safety net if timeout fired
     let _ = edge_id; // used for logging context
 }
 
@@ -784,6 +879,7 @@ mod tests {
             hub_port: 9999,
             edge_id: "e1".to_string(),
             secret: "sec".to_string(),
+            bind_address: None,
         };
         let json = serde_json::to_string(&config).unwrap();
         let back: EdgeConfig = serde_json::from_str(&json).unwrap();
@@ -899,6 +995,7 @@ mod tests {
             hub_port: 8443,
             edge_id: "test-edge".to_string(),
             secret: "test-secret".to_string(),
+            bind_address: None,
         });
         let status = edge.get_status().await;
         assert!(!status.running);
@@ -915,6 +1012,7 @@ mod tests {
             hub_port: 8443,
             edge_id: "e".to_string(),
             secret: "s".to_string(),
+            bind_address: None,
         });
         let rx1 = edge.take_event_rx().await;
         assert!(rx1.is_some());
@@ -929,6 +1027,7 @@ mod tests {
             hub_port: 8443,
             edge_id: "e".to_string(),
             secret: "s".to_string(),
+            bind_address: None,
         });
         edge.stop().await; // should not panic
         let status = edge.get_status().await;

rust/crates/remoteingress-core/src/hub.rs

@@ -298,6 +298,15 @@ async fn handle_edge_connection(
     edge_token: CancellationToken,
     peer_addr: String,
 ) -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
+    // Disable Nagle's algorithm for low-latency control frames (PING/PONG, WINDOW_UPDATE)
+    stream.set_nodelay(true)?;
+    // TCP keepalive detects silent network failures (NAT timeout, path change)
+    // faster than the 45s application-level liveness timeout.
+    let ka = socket2::TcpKeepalive::new()
+        .with_time(Duration::from_secs(30));
+    #[cfg(target_os = "linux")]
+    let ka = ka.with_interval(Duration::from_secs(10));
+    let _ = socket2::SockRef::from(&stream).set_tcp_keepalive(&ka);
     let tls_stream = acceptor.accept(stream).await?;
     let (read_half, mut write_half) = tokio::io::split(tls_stream);
     let mut buf_reader = BufReader::new(read_half);
@@ -371,23 +380,30 @@ async fn handle_edge_connection(
         );
     }
 
+    // Per-edge active stream counter for adaptive flow control
+    let edge_stream_count = Arc::new(AtomicU32::new(0));
+
     // QoS dual-channel tunnel writer: control frames (PING/PONG/WINDOW_UPDATE/CLOSE)
     // have priority over data frames (DATA_BACK). This prevents PING starvation under load.
-    let (ctrl_tx, mut ctrl_rx) = mpsc::channel::<Vec<u8>>(64);
+    let (ctrl_tx, mut ctrl_rx) = mpsc::channel::<Vec<u8>>(256);
     let (data_tx, mut data_rx) = mpsc::channel::<Vec<u8>>(4096);
     // Legacy alias for code that sends both control and data (will be migrated)
     let frame_writer_tx = ctrl_tx.clone();
     let writer_token = edge_token.clone();
+    let (writer_dead_tx, mut writer_dead_rx) = tokio::sync::oneshot::channel::<()>();
     let writer_handle = tokio::spawn(async move {
+        // BufWriter coalesces small writes (frame headers, control frames) into fewer
+        // TLS records and syscalls. Flushed after each frame to avoid holding data.
+        let mut writer = tokio::io::BufWriter::with_capacity(65536, write_half);
+        let mut write_error = false;
         loop {
             tokio::select! {
                 biased; // control frames always take priority over data
                 ctrl = ctrl_rx.recv() => {
                     match ctrl {
                         Some(frame_data) => {
-                            if write_half.write_all(&frame_data).await.is_err() {
-                                break;
-                            }
+                            if writer.write_all(&frame_data).await.is_err() { write_error = true; break; }
+                            if writer.flush().await.is_err() { write_error = true; break; }
                         }
                         None => break,
                     }
@@ -395,9 +411,8 @@ async fn handle_edge_connection(
                 data = data_rx.recv() => {
                     match data {
                         Some(frame_data) => {
-                            if write_half.write_all(&frame_data).await.is_err() {
-                                break;
-                            }
+                            if writer.write_all(&frame_data).await.is_err() { write_error = true; break; }
+                            if writer.flush().await.is_err() { write_error = true; break; }
                         }
                         None => break,
                     }
@@ -405,6 +420,10 @@ async fn handle_edge_connection(
                 _ = writer_token.cancelled() => break,
             }
         }
+        if write_error {
+            log::error!("Tunnel writer to edge failed, signalling reader for fast cleanup");
+            let _ = writer_dead_tx.send(());
+        }
     });
 
     // Spawn task to forward config updates as FRAME_CONFIG frames
@@ -506,8 +525,10 @@ async fn handle_edge_connection(
                                 }
 
                                 // Spawn task: connect to SmartProxy, send PROXY header, pipe data
+                                let stream_counter = Arc::clone(&edge_stream_count);
                                 tokio::spawn(async move {
                                     let _permit = permit; // hold semaphore permit until stream completes
+                                    stream_counter.fetch_add(1, Ordering::Relaxed);
 
                                     let result = async {
                                         // A2: Connect to SmartProxy with timeout
@@ -520,6 +541,7 @@ async fn handle_edge_connection(
                                             format!("connect to SmartProxy {}:{} timed out (10s)", target, dest_port).into()
                                         })??;
 
+                                        upstream.set_nodelay(true)?;
                                         upstream.write_all(proxy_header.as_bytes()).await?;
 
                                         let (mut up_read, mut up_write) =
@@ -529,6 +551,7 @@ async fn handle_edge_connection(
                                         // After writing to upstream, send WINDOW_UPDATE_BACK to edge
                                         let writer_token = stream_token.clone();
                                         let wub_tx = writer_tx.clone();
+                                        let stream_counter_w = Arc::clone(&stream_counter);
                                         let writer_for_edge_data = tokio::spawn(async move {
                                             let mut consumed_since_update: u32 = 0;
                                             loop {
@@ -537,10 +560,16 @@ async fn handle_edge_connection(
                                                         match data {
                                                             Some(data) => {
                                                                 let len = data.len() as u32;
-                                                                match tokio::time::timeout(
-                                                                    Duration::from_secs(60),
-                                                                    up_write.write_all(&data),
-                                                                ).await {
+                                                                // Check cancellation alongside the write so we respond
+                                                                // promptly to FRAME_CLOSE instead of blocking up to 60s.
+                                                                let write_result = tokio::select! {
+                                                                    r = tokio::time::timeout(
+                                                                        Duration::from_secs(60),
+                                                                        up_write.write_all(&data),
+                                                                    ) => r,
+                                                                    _ = writer_token.cancelled() => break,
+                                                                };
+                                                                match write_result {
                                                                     Ok(Ok(())) => {}
                                                                     Ok(Err(_)) => break,
                                                                     Err(_) => {
@@ -548,12 +577,18 @@ async fn handle_edge_connection(
                                                                         break;
                                                                     }
                                                                 }
-                                                                // Track consumption for flow control
+                                                                // Track consumption for adaptive flow control.
+                                                                // Increment capped to adaptive window to limit per-stream in-flight data.
                                                                 consumed_since_update += len;
-                                                                if consumed_since_update >= WINDOW_UPDATE_THRESHOLD {
-                                                                    let frame = encode_window_update(stream_id, FRAME_WINDOW_UPDATE_BACK, consumed_since_update);
+                                                                let adaptive_window = remoteingress_protocol::compute_window_for_stream_count(
+                                                                    stream_counter_w.load(Ordering::Relaxed),
+                                                                );
+                                                                let threshold = adaptive_window / 2;
+                                                                if consumed_since_update >= threshold {
+                                                                    let increment = consumed_since_update.min(adaptive_window);
+                                                                    let frame = encode_window_update(stream_id, FRAME_WINDOW_UPDATE_BACK, increment);
                                                                     if wub_tx.try_send(frame).is_ok() {
-                                                                        consumed_since_update = 0;
+                                                                        consumed_since_update -= increment;
                                                                     }
                                                                     // If try_send fails, keep accumulating — retry on next threshold
                                                                 }
@@ -591,9 +626,20 @@ async fn handle_edge_connection(
                                             }
                                             if stream_token.is_cancelled() { break; }
 
-                                            // Limit read size to available window
+                                            // Limit read size to available window.
+                                            // IMPORTANT: if window is 0 (stall timeout fired), we must NOT
+                                            // read into an empty buffer — read(&mut buf[..0]) returns Ok(0)
+                                            // which would be falsely interpreted as EOF.
                                             let w = send_window.load(Ordering::Acquire) as usize;
-                                            let max_read = w.min(buf.len());
+                                            if w == 0 {
+                                                log::warn!("Stream {} download: window still 0 after stall timeout, closing", stream_id);
+                                                break;
+                                            }
+                                            // Adaptive: cap read to current per-stream target window
+                                            let adaptive_cap = remoteingress_protocol::compute_window_for_stream_count(
+                                                stream_counter.load(Ordering::Relaxed),
+                                            ) as usize;
+                                            let max_read = w.min(buf.len()).min(adaptive_cap);
 
                                             tokio::select! {
                                                 read_result = up_read.read(&mut buf[..max_read]) => {
@@ -615,10 +661,11 @@ async fn handle_edge_connection(
                                             }
                                         }
 
-                                        // Send CLOSE_BACK via DATA channel (must arrive AFTER last DATA_BACK)
+                                        // Send CLOSE_BACK via DATA channel (must arrive AFTER last DATA_BACK).
+                                        // Use send().await to guarantee delivery (try_send silently drops if full).
                                         if !stream_token.is_cancelled() {
                                             let close_frame = encode_frame(stream_id, FRAME_CLOSE_BACK, &[]);
-                                            let _ = data_writer_tx.try_send(close_frame);
+                                            let _ = data_writer_tx.send(close_frame).await;
                                         }
 
                                         writer_for_edge_data.abort();
@@ -628,10 +675,11 @@ async fn handle_edge_connection(
 
                                     if let Err(e) = result {
                                         log::error!("Stream {} error: {}", stream_id, e);
-                                        // Send CLOSE_BACK via DATA channel on error (must arrive after any DATA_BACK)
+                                        // Send CLOSE_BACK via DATA channel on error (must arrive after any DATA_BACK).
+                                        // Use send().await to guarantee delivery.
                                         if !stream_token.is_cancelled() {
                                             let close_frame = encode_frame(stream_id, FRAME_CLOSE_BACK, &[]);
-                                            let _ = data_writer_tx.try_send(close_frame);
+                                            let _ = data_writer_tx.send(close_frame).await;
                                         }
                                     }
 
@@ -646,6 +694,7 @@ async fn handle_edge_connection(
                                             stream_id,
                                         });
                                     }
+                                    stream_counter.fetch_sub(1, Ordering::Relaxed);
                                 });
                             }
                             FRAME_DATA => {
@@ -707,8 +756,9 @@ async fn handle_edge_connection(
             _ = ping_ticker.tick() => {
                 let ping_frame = encode_frame(0, FRAME_PING, &[]);
                 if frame_writer_tx.try_send(ping_frame).is_err() {
-                    log::warn!("Failed to send PING to edge {}, writer channel full/closed", edge_id);
-                    break;
+                    // Control channel full — skip this PING cycle.
+                    // The 45s liveness timeout gives margin for the channel to drain.
+                    log::warn!("PING send to edge {} failed, control channel full — skipping", edge_id);
                 }
                 log::trace!("Sent PING to edge {}", edge_id);
             }
@@ -717,6 +767,10 @@ async fn handle_edge_connection(
                     edge_id, liveness_timeout_dur.as_secs());
                 break;
             }
+            _ = &mut writer_dead_rx => {
+                log::error!("Tunnel writer to edge {} died, disconnecting immediately", edge_id);
+                break;
+            }
             _ = edge_token.cancelled() => {
                 log::info!("Edge {} cancelled by hub", edge_id);
                 break;

rust/crates/remoteingress-protocol/Cargo.toml

@@ -5,3 +5,6 @@ edition = "2021"
 
 [dependencies]
 tokio = { version = "1", features = ["io-util"] }
+
+[dev-dependencies]
+tokio = { version = "1", features = ["io-util", "macros", "rt"] }

rust/crates/remoteingress-protocol/src/lib.rs

@@ -32,6 +32,15 @@ pub fn encode_window_update(stream_id: u32, frame_type: u8, increment: u32) -> V
     encode_frame(stream_id, frame_type, &increment.to_be_bytes())
 }
 
+/// Compute the target per-stream window size based on the number of active streams.
+/// Total memory budget is ~32MB shared across all streams. As more streams are active,
+/// each gets a smaller window. This adapts to current demand — few streams get high
+/// throughput, many streams save memory and reduce control frame pressure.
+pub fn compute_window_for_stream_count(active: u32) -> u32 {
+    let per_stream = (32 * 1024 * 1024u64) / (active.max(1) as u64);
+    per_stream.clamp(64 * 1024, INITIAL_STREAM_WINDOW as u64) as u32
+}
+
 /// Decode a WINDOW_UPDATE payload into a byte increment. Returns None if payload is malformed.
 pub fn decode_window_update(payload: &[u8]) -> Option<u32> {
     if payload.len() != 4 {
@@ -336,4 +345,134 @@ mod tests {
         assert_eq!(&pong[0..4], &0u32.to_be_bytes());
         assert_eq!(pong.len(), FRAME_HEADER_SIZE);
     }
+
+    // --- compute_window_for_stream_count tests ---
+
+    #[test]
+    fn test_adaptive_window_zero_streams() {
+        // 0 streams treated as 1: 32MB/1 = 32MB → clamped to 4MB max
+        assert_eq!(compute_window_for_stream_count(0), INITIAL_STREAM_WINDOW);
+    }
+
+    #[test]
+    fn test_adaptive_window_one_stream() {
+        // 32MB/1 = 32MB → clamped to 4MB max
+        assert_eq!(compute_window_for_stream_count(1), INITIAL_STREAM_WINDOW);
+    }
+
+    #[test]
+    fn test_adaptive_window_at_max_boundary() {
+        // 32MB/8 = 4MB = exactly INITIAL_STREAM_WINDOW
+        assert_eq!(compute_window_for_stream_count(8), INITIAL_STREAM_WINDOW);
+    }
+
+    #[test]
+    fn test_adaptive_window_just_below_max() {
+        // 32MB/9 = 3,728,270 — first value below INITIAL_STREAM_WINDOW
+        let w = compute_window_for_stream_count(9);
+        assert!(w < INITIAL_STREAM_WINDOW);
+        assert_eq!(w, (32 * 1024 * 1024u64 / 9) as u32);
+    }
+
+    #[test]
+    fn test_adaptive_window_16_streams() {
+        // 32MB/16 = 2MB
+        assert_eq!(compute_window_for_stream_count(16), 2 * 1024 * 1024);
+    }
+
+    #[test]
+    fn test_adaptive_window_100_streams() {
+        // 32MB/100 = 335,544 bytes (~327KB)
+        let w = compute_window_for_stream_count(100);
+        assert_eq!(w, (32 * 1024 * 1024u64 / 100) as u32);
+        assert!(w > 64 * 1024); // above floor
+        assert!(w < INITIAL_STREAM_WINDOW as u32); // below ceiling
+    }
+
+    #[test]
+    fn test_adaptive_window_200_streams() {
+        // 32MB/200 = 167,772 bytes (~163KB), above 64KB floor
+        let w = compute_window_for_stream_count(200);
+        assert_eq!(w, (32 * 1024 * 1024u64 / 200) as u32);
+        assert!(w > 64 * 1024);
+    }
+
+    #[test]
+    fn test_adaptive_window_500_streams() {
+        // 32MB/500 = 67,108 bytes (~65.5KB), just above 64KB floor
+        let w = compute_window_for_stream_count(500);
+        assert_eq!(w, (32 * 1024 * 1024u64 / 500) as u32);
+        assert!(w > 64 * 1024);
+    }
+
+    #[test]
+    fn test_adaptive_window_at_min_boundary() {
+        // 32MB/512 = 65,536 = exactly 64KB floor
+        assert_eq!(compute_window_for_stream_count(512), 64 * 1024);
+    }
+
+    #[test]
+    fn test_adaptive_window_below_min_clamped() {
+        // 32MB/513 = 65,408 → clamped up to 64KB
+        assert_eq!(compute_window_for_stream_count(513), 64 * 1024);
+    }
+
+    #[test]
+    fn test_adaptive_window_1000_streams() {
+        // 32MB/1000 = 33,554 → clamped to 64KB
+        assert_eq!(compute_window_for_stream_count(1000), 64 * 1024);
+    }
+
+    #[test]
+    fn test_adaptive_window_max_u32() {
+        // Extreme: u32::MAX streams → tiny value → clamped to 64KB
+        assert_eq!(compute_window_for_stream_count(u32::MAX), 64 * 1024);
+    }
+
+    #[test]
+    fn test_adaptive_window_monotonically_decreasing() {
+        // Window should decrease (or stay same) as stream count increases
+        let mut prev = compute_window_for_stream_count(1);
+        for n in [2, 5, 10, 50, 100, 200, 500, 512, 1000] {
+            let w = compute_window_for_stream_count(n);
+            assert!(w <= prev, "window increased from {} to {} at n={}", prev, w, n);
+            prev = w;
+        }
+    }
+
+    #[test]
+    fn test_adaptive_window_total_budget_bounded() {
+        // active × per_stream_window should never exceed 32MB (+ clamp overhead for high N)
+        for n in [1, 10, 50, 100, 200, 500] {
+            let w = compute_window_for_stream_count(n);
+            let total = w as u64 * n as u64;
+            assert!(total <= 32 * 1024 * 1024, "total {}MB exceeds budget at n={}", total / (1024*1024), n);
+        }
+    }
+
+    // --- encode/decode window_update roundtrip ---
+
+    #[test]
+    fn test_window_update_roundtrip() {
+        for &increment in &[0u32, 1, 64 * 1024, INITIAL_STREAM_WINDOW, MAX_WINDOW_SIZE, u32::MAX] {
+            let frame = encode_window_update(42, FRAME_WINDOW_UPDATE, increment);
+            assert_eq!(frame[4], FRAME_WINDOW_UPDATE);
+            let decoded = decode_window_update(&frame[FRAME_HEADER_SIZE..]);
+            assert_eq!(decoded, Some(increment));
+        }
+    }
+
+    #[test]
+    fn test_window_update_back_roundtrip() {
+        let frame = encode_window_update(7, FRAME_WINDOW_UPDATE_BACK, 1234567);
+        assert_eq!(frame[4], FRAME_WINDOW_UPDATE_BACK);
+        assert_eq!(decode_window_update(&frame[FRAME_HEADER_SIZE..]), Some(1234567));
+    }
+
+    #[test]
+    fn test_decode_window_update_malformed() {
+        assert_eq!(decode_window_update(&[]), None);
+        assert_eq!(decode_window_update(&[0, 0, 0]), None);
+        assert_eq!(decode_window_update(&[0, 0, 0, 0, 0]), None);
+    }
 }

test/test.flowcontrol.node.ts

@@ -0,0 +1,475 @@
+import { expect, tap } from '@push.rocks/tapbundle';
+import * as net from 'net';
+import * as crypto from 'crypto';
+import { RemoteIngressHub, RemoteIngressEdge } from '../ts/index.js';
+
+// ---------------------------------------------------------------------------
+// Helpers
+// ---------------------------------------------------------------------------
+
+/** Find N free ports by binding to port 0 and collecting OS-assigned ports. */
+async function findFreePorts(count: number): Promise<number[]> {
+  const servers: net.Server[] = [];
+  const ports: number[] = [];
+  for (let i = 0; i < count; i++) {
+    const server = net.createServer();
+    await new Promise<void>((resolve) => server.listen(0, '127.0.0.1', resolve));
+    ports.push((server.address() as net.AddressInfo).port);
+    servers.push(server);
+  }
+  await Promise.all(servers.map((s) => new Promise<void>((resolve) => s.close(() => resolve()))));
+  return ports;
+}
+
+type TrackingServer = net.Server & { destroyAll: () => void };
+
+/** Start a TCP echo server that tracks connections for force-close. */
+function startEchoServer(port: number, host: string): Promise<TrackingServer> {
+  return new Promise((resolve, reject) => {
+    const connections = new Set<net.Socket>();
+    const server = net.createServer((socket) => {
+      connections.add(socket);
+      socket.on('close', () => connections.delete(socket));
+
+      // Skip PROXY protocol v1 header line before echoing
+      let proxyHeaderParsed = false;
+      let pendingBuf = Buffer.alloc(0);
+      socket.on('data', (data: Buffer) => {
+        if (!proxyHeaderParsed) {
+          pendingBuf = Buffer.concat([pendingBuf, data]);
+          const idx = pendingBuf.indexOf('\r\n');
+          if (idx !== -1) {
+            proxyHeaderParsed = true;
+            const remainder = pendingBuf.subarray(idx + 2);
+            if (remainder.length > 0) {
+              socket.write(remainder);
+            }
+          }
+          return;
+        }
+        socket.write(data);
+      });
+      socket.on('error', () => {});
+    }) as TrackingServer;
+
+    server.destroyAll = () => {
+      for (const conn of connections) conn.destroy();
+      connections.clear();
+    };
+
+    server.on('error', reject);
+    server.listen(port, host, () => resolve(server));
+  });
+}
+
+/**
+ * Start a server that sends a large response immediately on first data received.
+ * Does NOT wait for end (the tunnel protocol has no half-close).
+ * On receiving first data chunk after PROXY header, sends responseSize bytes then closes.
+ */
+function startLargeResponseServer(port: number, host: string, responseSize: number): Promise<TrackingServer> {
+  return new Promise((resolve, reject) => {
+    const connections = new Set<net.Socket>();
+    const server = net.createServer((socket) => {
+      connections.add(socket);
+      socket.on('close', () => connections.delete(socket));
+
+      let proxyHeaderParsed = false;
+      let pendingBuf = Buffer.alloc(0);
+      let responseSent = false;
+
+      socket.on('data', (data: Buffer) => {
+        if (!proxyHeaderParsed) {
+          pendingBuf = Buffer.concat([pendingBuf, data]);
+          const idx = pendingBuf.indexOf('\r\n');
+          if (idx !== -1) {
+            proxyHeaderParsed = true;
+            const remainder = pendingBuf.subarray(idx + 2);
+            if (remainder.length > 0 && !responseSent) {
+              responseSent = true;
+              sendLargeResponse(socket, responseSize);
+            }
+          }
+          return;
+        }
+        if (!responseSent) {
+          responseSent = true;
+          sendLargeResponse(socket, responseSize);
+        }
+      });
+      socket.on('error', () => {});
+    }) as TrackingServer;
+
+    server.destroyAll = () => {
+      for (const conn of connections) conn.destroy();
+      connections.clear();
+    };
+
+    server.on('error', reject);
+    server.listen(port, host, () => resolve(server));
+  });
+}
+
+function sendLargeResponse(socket: net.Socket, totalBytes: number) {
+  const chunkSize = 32 * 1024;
+  let sent = 0;
+  const writeChunk = () => {
+    while (sent < totalBytes) {
+      const toWrite = Math.min(chunkSize, totalBytes - sent);
+      // Use a deterministic pattern for verification
+      const chunk = Buffer.alloc(toWrite, (sent % 256) & 0xff);
+      const canContinue = socket.write(chunk);
+      sent += toWrite;
+      if (!canContinue) {
+        socket.once('drain', writeChunk);
+        return;
+      }
+    }
+    socket.end();
+  };
+  writeChunk();
+}
+
+/** Force-close a server: destroy all connections, then close. */
+async function forceCloseServer(server: TrackingServer): Promise<void> {
+  server.destroyAll();
+  await new Promise<void>((resolve) => server.close(() => resolve()));
+}
+
+interface TestTunnel {
+  hub: RemoteIngressHub;
+  edge: RemoteIngressEdge;
+  edgePort: number;
+  cleanup: () => Promise<void>;
+}
+
+/**
+ * Start a full hub + edge tunnel.
+ * Edge binds to 127.0.0.1, upstream server binds to 127.0.0.2.
+ * Hub targetHost = 127.0.0.2 so hub -> upstream doesn't loop back to edge.
+ */
+async function startTunnel(edgePort: number, hubPort: number): Promise<TestTunnel> {
+  const hub = new RemoteIngressHub();
+  const edge = new RemoteIngressEdge();
+
+  await hub.start({
+    tunnelPort: hubPort,
+    targetHost: '127.0.0.2',
+  });
+
+  await hub.updateAllowedEdges([
+    { id: 'test-edge', secret: 'test-secret', listenPorts: [edgePort] },
+  ]);
+
+  const connectedPromise = new Promise<void>((resolve, reject) => {
+    const timeout = setTimeout(() => reject(new Error('Edge did not connect within 10s')), 10000);
+    edge.once('tunnelConnected', () => {
+      clearTimeout(timeout);
+      resolve();
+    });
+  });
+
+  await edge.start({
+    hubHost: '127.0.0.1',
+    hubPort,
+    edgeId: 'test-edge',
+    secret: 'test-secret',
+    bindAddress: '127.0.0.1',
+  });
+
+  await connectedPromise;
+  await new Promise((resolve) => setTimeout(resolve, 500));
+
+  return {
+    hub,
+    edge,
+    edgePort,
+    cleanup: async () => {
+      await edge.stop();
+      await hub.stop();
+    },
+  };
+}
+
+/**
+ * Send data through the tunnel and collect the echoed response.
+ */
+function sendAndReceive(port: number, data: Buffer, timeoutMs = 30000): Promise<Buffer> {
+  return new Promise((resolve, reject) => {
+    const chunks: Buffer[] = [];
+    let totalReceived = 0;
+    const expectedLength = data.length;
+    let settled = false;
+
+    const client = net.createConnection({ host: '127.0.0.1', port }, () => {
+      client.write(data);
+      client.end();
+    });
+
+    const timer = setTimeout(() => {
+      if (!settled) {
+        settled = true;
+        client.destroy();
+        reject(new Error(`Timeout after ${timeoutMs}ms — received ${totalReceived}/${expectedLength} bytes`));
+      }
+    }, timeoutMs);
+
+    client.on('data', (chunk: Buffer) => {
+      chunks.push(chunk);
+      totalReceived += chunk.length;
+      if (totalReceived >= expectedLength && !settled) {
+        settled = true;
+        clearTimeout(timer);
+        client.destroy();
+        resolve(Buffer.concat(chunks));
+      }
+    });
+
+    client.on('end', () => {
+      if (!settled) {
+        settled = true;
+        clearTimeout(timer);
+        resolve(Buffer.concat(chunks));
+      }
+    });
+
+    client.on('error', (err) => {
+      if (!settled) {
+        settled = true;
+        clearTimeout(timer);
+        reject(err);
+      }
+    });
+  });
+}
+
+/**
+ * Connect to the tunnel, send a small request, and collect a large response.
+ * Does NOT call end() — the tunnel has no half-close.
+ * Instead, collects until expectedResponseSize bytes arrive.
+ */
+function sendAndReceiveLarge(
+  port: number,
+  data: Buffer,
+  expectedResponseSize: number,
+  timeoutMs = 60000,
+): Promise<Buffer> {
+  return new Promise((resolve, reject) => {
+    const chunks: Buffer[] = [];
+    let totalReceived = 0;
+    let settled = false;
+
+    const client = net.createConnection({ host: '127.0.0.1', port }, () => {
+      client.write(data);
+      // Do NOT call client.end() — the server will respond immediately
+      // and the tunnel CLOSE will happen when the download finishes
+    });
+
+    const timer = setTimeout(() => {
+      if (!settled) {
+        settled = true;
+        client.destroy();
+        reject(new Error(`Timeout after ${timeoutMs}ms — received ${totalReceived}/${expectedResponseSize} bytes`));
+      }
+    }, timeoutMs);
+
+    client.on('data', (chunk: Buffer) => {
+      chunks.push(chunk);
+      totalReceived += chunk.length;
+      if (totalReceived >= expectedResponseSize && !settled) {
+        settled = true;
+        clearTimeout(timer);
+        client.destroy();
+        resolve(Buffer.concat(chunks));
+      }
+    });
+
+    client.on('end', () => {
+      if (!settled) {
+        settled = true;
+        clearTimeout(timer);
+        resolve(Buffer.concat(chunks));
+      }
+    });
+
+    client.on('error', (err) => {
+      if (!settled) {
+        settled = true;
+        clearTimeout(timer);
+        reject(err);
+      }
+    });
+  });
+}
+
+function sha256(buf: Buffer): string {
+  return crypto.createHash('sha256').update(buf).digest('hex');
+}
+
+// ---------------------------------------------------------------------------
+// Tests
+// ---------------------------------------------------------------------------
+
+let tunnel: TestTunnel;
+let echoServer: TrackingServer;
+let hubPort: number;
+let edgePort: number;
+
+tap.test('setup: start echo server and tunnel', async () => {
+  [hubPort, edgePort] = await findFreePorts(2);
+
+  echoServer = await startEchoServer(edgePort, '127.0.0.2');
+  tunnel = await startTunnel(edgePort, hubPort);
+
+  expect(tunnel.hub.running).toBeTrue();
+});
+
+tap.test('single stream: 32MB transfer exceeding initial 4MB window', async () => {
+  const size = 32 * 1024 * 1024;
+  const data = crypto.randomBytes(size);
+  const expectedHash = sha256(data);
+
+  const received = await sendAndReceive(edgePort, data, 60000);
+
+  expect(received.length).toEqual(size);
+  expect(sha256(received)).toEqual(expectedHash);
+});
+
+tap.test('200 concurrent streams with 64KB each', async () => {
+  const streamCount = 200;
+  const payloadSize = 64 * 1024;
+
+  const promises = Array.from({ length: streamCount }, () => {
+    const data = crypto.randomBytes(payloadSize);
+    const hash = sha256(data);
+    return sendAndReceive(edgePort, data, 30000).then((received) => ({
+      sent: hash,
+      received: sha256(received),
+      sizeOk: received.length === payloadSize,
+    }));
+  });
+
+  const results = await Promise.all(promises);
+  const failures = results.filter((r) => !r.sizeOk || r.sent !== r.received);
+
+  expect(failures.length).toEqual(0);
+});
+
+tap.test('512 concurrent streams at minimum window boundary (16KB each)', async () => {
+  const streamCount = 512;
+  const payloadSize = 16 * 1024;
+
+  const promises = Array.from({ length: streamCount }, () => {
+    const data = crypto.randomBytes(payloadSize);
+    const hash = sha256(data);
+    return sendAndReceive(edgePort, data, 60000).then((received) => ({
+      sent: hash,
+      received: sha256(received),
+      sizeOk: received.length === payloadSize,
+    }));
+  });
+
+  const results = await Promise.all(promises);
+  const failures = results.filter((r) => !r.sizeOk || r.sent !== r.received);
+
+  expect(failures.length).toEqual(0);
+});
+
+tap.test('asymmetric transfer: 4KB request -> 4MB response', async () => {
+  // Swap to large-response server
+  await forceCloseServer(echoServer);
+  const responseSize = 4 * 1024 * 1024; // 4 MB
+  const largeServer = await startLargeResponseServer(edgePort, '127.0.0.2', responseSize);
+
+  try {
+    const requestData = crypto.randomBytes(4 * 1024); // 4 KB
+    const received = await sendAndReceiveLarge(edgePort, requestData, responseSize, 60000);
+    expect(received.length).toEqual(responseSize);
+  } finally {
+    // Always restore echo server even on failure
+    await forceCloseServer(largeServer);
+    echoServer = await startEchoServer(edgePort, '127.0.0.2');
+  }
+});
+
+tap.test('100 streams x 1MB each (100MB total exceeding 32MB budget)', async () => {
+  const streamCount = 100;
+  const payloadSize = 1 * 1024 * 1024;
+
+  const promises = Array.from({ length: streamCount }, () => {
+    const data = crypto.randomBytes(payloadSize);
+    const hash = sha256(data);
+    return sendAndReceive(edgePort, data, 120000).then((received) => ({
+      sent: hash,
+      received: sha256(received),
+      sizeOk: received.length === payloadSize,
+    }));
+  });
+
+  const results = await Promise.all(promises);
+  const failures = results.filter((r) => !r.sizeOk || r.sent !== r.received);
+
+  expect(failures.length).toEqual(0);
+});
+
+tap.test('active stream counter tracks concurrent connections', async () => {
+  const N = 50;
+
+  // Open N connections and keep them alive (send data but don't close)
+  const sockets: net.Socket[] = [];
+  const connectPromises = Array.from({ length: N }, () => {
+    return new Promise<net.Socket>((resolve, reject) => {
+      const sock = net.createConnection({ host: '127.0.0.1', port: edgePort }, () => {
+        resolve(sock);
+      });
+      sock.on('error', () => {});
+      setTimeout(() => reject(new Error('connect timeout')), 5000);
+    });
+  });
+
+  const connected = await Promise.all(connectPromises);
+  sockets.push(...connected);
+
+  // Brief delay for stream registration to propagate
+  await new Promise((resolve) => setTimeout(resolve, 500));
+
+  // Verify the edge reports >= N active streams.
+  // This counter is the input to compute_window_for_stream_count(),
+  // so its accuracy determines whether adaptive window sizing is correct.
+  const status = await tunnel.edge.getStatus();
+  expect(status.activeStreams).toBeGreaterThanOrEqual(N);
+
+  // Clean up: destroy all sockets (the tunnel's 300s stream timeout will handle cleanup)
+  for (const sock of sockets) {
+    sock.destroy();
+  }
+});
+
+tap.test('50 streams x 2MB each (forces multiple window refills per stream)', async () => {
+  // At 50 concurrent streams: adaptive window = 32MB/50 = 655KB per stream
+  // Each stream sends 2MB → needs ~3 WINDOW_UPDATE refill cycles per stream
+  const streamCount = 50;
+  const payloadSize = 2 * 1024 * 1024;
+
+  const promises = Array.from({ length: streamCount }, () => {
+    const data = crypto.randomBytes(payloadSize);
+    const hash = sha256(data);
+    return sendAndReceive(edgePort, data, 120000).then((received) => ({
+      sent: hash,
+      received: sha256(received),
+      sizeOk: received.length === payloadSize,
+    }));
+  });
+
+  const results = await Promise.all(promises);
+  const failures = results.filter((r) => !r.sizeOk || r.sent !== r.received);
+
+  expect(failures.length).toEqual(0);
+});
+
+tap.test('teardown: stop tunnel and echo server', async () => {
+  await tunnel.cleanup();
+  await forceCloseServer(echoServer);
+});
+
+export default tap.start();

ts/00_commitinfo_data.ts

@@ -3,6 +3,6 @@
  */
 export const commitinfo = {
   name: '@serve.zone/remoteingress',
-  version: '4.5.4',
+  version: '4.7.1',
   description: 'Edge ingress tunnel for DcRouter - accepts incoming TCP connections at network edge and tunnels them to DcRouter SmartProxy preserving client IP via PROXY protocol v1.'
 }

ts/classes.remoteingressedge.ts

@@ -14,6 +14,7 @@ type TEdgeCommands = {
       hubPort: number;
       edgeId: string;
       secret: string;
+      bindAddress?: string;
     };
     result: { started: boolean };
   };
@@ -38,6 +39,7 @@ export interface IEdgeConfig {
   hubPort?: number;
   edgeId: string;
   secret: string;
+  bindAddress?: string;
 }
 
 const MAX_RESTART_ATTEMPTS = 10;
@@ -132,6 +134,7 @@ export class RemoteIngressEdge extends EventEmitter {
       hubPort: edgeConfig.hubPort ?? 8443,
       edgeId: edgeConfig.edgeId,
       secret: edgeConfig.secret,
+      ...(edgeConfig.bindAddress ? { bindAddress: edgeConfig.bindAddress } : {}),
     });
 
     this.started = true;
@@ -227,6 +230,7 @@ export class RemoteIngressEdge extends EventEmitter {
         hubPort: this.savedConfig.hubPort ?? 8443,
         edgeId: this.savedConfig.edgeId,
         secret: this.savedConfig.secret,
+        ...(this.savedConfig.bindAddress ? { bindAddress: this.savedConfig.bindAddress } : {}),
       });
 
       this.started = true;