diff --git a/src/demo-server.rs b/src/demo-server.rs
new file mode 100644
index 000000000..694aa0272
--- /dev/null
+++ b/src/demo-server.rs
@@ -0,0 +1,129 @@
+use hbb_common::{
+    bytes::BytesMut,
+    protobuf::Message as _,
+    rendezvous_proto::*,
+    tcp::{new_listener, FramedStream},
+    tokio,
+    udp::FramedSocket,
+};
+
+#[tokio::main(basic_scheduler)]
+async fn main() {
+    let mut socket = FramedSocket::new("0.0.0.0:21116").await.unwrap();
+    let mut listener = new_listener("0.0.0.0:21116", false).await.unwrap();
+    let mut rlistener = new_listener("0.0.0.0:21117", false).await.unwrap();
+    let mut id_map = std::collections::HashMap::new();
+    let relay_server = std::env::var("IP").unwrap();
+    let mut saved_stream = None;
+    loop {
+        tokio::select! {
+            Some(Ok((bytes, addr))) = socket.next() => {
+                handle_udp(&mut socket, bytes, addr, &mut id_map).await;
+            }
+            Ok((stream, addr)) = listener.accept() => {
+                let mut stream = FramedStream::from(stream);
+                if let Some(Ok(bytes)) = stream.next_timeout(3000).await {
+                    if let Ok(msg_in) = RendezvousMessage::parse_from_bytes(&bytes) {
+                        match msg_in.union {
+                            Some(rendezvous_message::Union::punch_hole_request(ph)) => {
+                                println!("punch_hole_request {:?}", addr);
+                                if let Some(addr) = id_map.get(&ph.id) {
+                                    let mut msg_out = RendezvousMessage::new();
+                                    msg_out.set_request_relay(RequestRelay {
+                                        relay_server: relay_server.clone(),
+                                        ..Default::default()
+                                    });
+                                    socket.send(&msg_out, addr.clone()).await.ok();
+                                    saved_stream = Some(stream);
+                                }
+                            }
+                            Some(rendezvous_message::Union::relay_response(_)) => {
+                                println!("relay_response {:?}", addr);
+                                let mut msg_out = RendezvousMessage::new();
+                                msg_out.set_relay_response(RelayResponse {
+                                    relay_server: relay_server.clone(),
+                                    ..Default::default()
+                                });
+                                if let Some(mut stream) = saved_stream.take() {
+                                    stream.send(&msg_out).await.ok();
+                                    if let Ok((stream_a, _)) = rlistener.accept().await {
+                                        let mut stream_a = FramedStream::from(stream_a);
+                                        stream_a.next_timeout(3_000).await;
+                                        if let Ok((stream_b, _)) = rlistener.accept().await {
+                                            let mut stream_b = FramedStream::from(stream_b);
+                                            stream_b.next_timeout(3_000).await;
+                                            relay(stream_a, stream_b, &mut socket, &mut id_map).await;
+                                        }
+                                    }
+                                }
+                            }
+                            _ => {}
+                        }
+                    }
+                }
+            }
+        }
+    }
+}
+
+async fn relay(
+    stream: FramedStream,
+    peer: FramedStream,
+    socket: &mut FramedSocket,
+    id_map: &mut std::collections::HashMap<String, std::net::SocketAddr>,
+) {
+    let mut peer = peer;
+    let mut stream = stream;
+    peer.set_raw();
+    stream.set_raw();
+    loop {
+        tokio::select! {
+            Some(Ok((bytes, addr))) = socket.next() => {
+                handle_udp(socket, bytes, addr, id_map).await;
+            }
+            res = peer.next() => {
+                if let Some(Ok(bytes)) = res {
+                    stream.send_bytes(bytes.into()).await.ok();
+                } else {
+                    break;
+                }
+            },
+            res = stream.next() => {
+                if let Some(Ok(bytes)) = res {
+                    peer.send_bytes(bytes.into()).await.ok();
+                } else {
+                    break;
+                }
+            },
+        }
+    }
+}
+
+async fn handle_udp(
+    socket: &mut FramedSocket,
+    bytes: BytesMut,
+    addr: std::net::SocketAddr,
+    id_map: &mut std::collections::HashMap<String, std::net::SocketAddr>,
+) {
+    if let Ok(msg_in) = RendezvousMessage::parse_from_bytes(&bytes) {
+        match msg_in.union {
+            Some(rendezvous_message::Union::register_peer(rp)) => {
+                println!("register_peer {:?}", addr);
+                id_map.insert(rp.id, addr);
+                let mut msg_out = RendezvousMessage::new();
+                msg_out.set_register_peer_response(RegisterPeerResponse::new());
+                socket.send(&msg_out, addr).await.ok();
+            }
+            Some(rendezvous_message::Union::register_pk(_)) => {
+                println!("register_pk {:?}", addr);
+                let mut msg_out = RendezvousMessage::new();
+                msg_out.set_register_pk_response(RegisterPkResponse {
+                    result: register_pk_response::Result::OK.into(),
+                    ..Default::default()
+                });
+                socket.send(&msg_out, addr).await.ok();
+            }
+            _ => {}
+        }
+    }
+}