diff --git a/iroh-net/src/magic_endpoint/rtt_actor.rs b/iroh-net/src/magic_endpoint/rtt_actor.rs
new file mode 100644
index 0000000000..006d2855b5
--- /dev/null
+++ b/iroh-net/src/magic_endpoint/rtt_actor.rs
@@ -0,0 +1,134 @@
+//! Actor which coordinates the congestion controller for the magic socket
+
+use std::collections::HashMap;
+use std::sync::Weak;
+
+use futures::StreamExt;
+use futures_concurrency::stream::stream_group;
+use tokio::sync::{mpsc, Notify};
+use tokio::task::JoinHandle;
+use tokio::time::Duration;
+use tracing::{debug, error, warn};
+
+use crate::magicsock::{ConnectionType, ConnectionTypeStream};
+
+#[derive(Debug)]
+pub(super) struct RttHandle {
+    pub(super) _handle: JoinHandle<()>,
+    pub(super) msg_tx: mpsc::Sender<RttMessage>,
+}
+
+impl RttHandle {
+    pub(super) fn new() -> Self {
+        let mut actor = RttActor {
+            connection_events: stream_group::StreamGroup::new().keyed(),
+            connections: HashMap::new(),
+            tick: Notify::new(),
+        };
+        let (msg_tx, msg_rx) = mpsc::channel(16);
+        let _handle = tokio::spawn(async move {
+            actor.run(msg_rx).await;
+        });
+        Self { _handle, msg_tx }
+    }
+}
+
+/// Messages to send to the [`RttActor`].
+#[derive(Debug)]
+pub(super) enum RttMessage {
+    /// Informs the [`RttActor`] of a new connection is should monitor.
+    NewConnection {
+        connection: Weak<quinn::ConnectionInner>,
+        conn_type_changes: ConnectionTypeStream,
+    },
+}
+
+/// Actor to coordinate congestion controller state with magic socket state.
+///
+/// The magic socket can change the underlying network path, between two nodes.  If we can
+/// inform the QUIC congestion controller of this event it will work much more efficiently.
+#[derive(Debug)]
+struct RttActor {
+    /// Stream of connection type changes.
+    connection_events: stream_group::Keyed<ConnectionTypeStream>,
+    /// References to the connections.
+    ///
+    /// These are weak references so not to keep the connections alive.  The key allows
+    /// removing the corresponding stream from `conn_type_changes`.
+    connections: HashMap<stream_group::Key, Weak<quinn::ConnectionInner>>,
+    /// A way to notify the main actor loop to run over.
+    ///
+    /// E.g. when a new stream was added.
+    tick: Notify,
+}
+
+impl RttActor {
+    /// Runs the actor main loop.
+    ///
+    /// The main loop will finish when the sender is dropped.
+    async fn run(&mut self, mut msg_rx: mpsc::Receiver<RttMessage>) {
+        let mut cleanup_interval = tokio::time::interval(Duration::from_secs(5));
+        cleanup_interval.set_missed_tick_behavior(tokio::time::MissedTickBehavior::Skip);
+        loop {
+            tokio::select! {
+                Some(msg) = msg_rx.recv() => self.handle_msg(msg),
+                item = self.connection_events.next(),
+                    if !self.connection_events.is_empty() => self.do_reset_rtt(item),
+                _ = cleanup_interval.tick() => self.do_connections_cleanup(),
+                () = self.tick.notified() => continue,
+                else => break,
+            }
+        }
+        debug!("rtt-actor finished");
+    }
+
+    /// Handle actor messages.
+    fn handle_msg(&mut self, msg: RttMessage) {
+        match msg {
+            RttMessage::NewConnection {
+                connection,
+                conn_type_changes,
+            } => {
+                self.handle_new_connection(connection, conn_type_changes);
+            }
+        }
+    }
+
+    /// Handles the new connection message.
+    fn handle_new_connection(
+        &mut self,
+        connection: Weak<quinn::ConnectionInner>,
+        conn_type_changes: ConnectionTypeStream,
+    ) {
+        let key = self.connection_events.insert(conn_type_changes);
+        self.connections.insert(key, connection);
+        self.tick.notify_one();
+    }
+
+    /// Performs the congestion controller reset for a magic socket path change.
+    fn do_reset_rtt(&mut self, item: Option<(stream_group::Key, ConnectionType)>) {
+        match item {
+            Some((key, _new_conn_type)) => match self.connections.get(&key) {
+                Some(conn) => match conn.upgrade() {
+                    Some(conn) => conn.reset_congestion_state(),
+                    None => {
+                        self.connection_events.remove(key);
+                    }
+                },
+                None => error!("No connection found for stream item"),
+            },
+            None => {
+                warn!("self.conn_type_changes is empty but was polled");
+            }
+        }
+    }
+
+    /// Performs cleanup for closed connection.
+    fn do_connections_cleanup(&mut self) {
+        for (key, conn) in self.connections.iter() {
+            if conn.upgrade().is_none() {
+                self.connection_events.remove(*key);
+            }
+        }
+    }
+}