diff --git a/prototypes/quic_demo/src/bin/client_gui.rs b/prototypes/quic_demo/src/bin/client_gui.rs
index ca6d6b9..4abafda 100644
--- a/prototypes/quic_demo/src/bin/client_gui.rs
+++ b/prototypes/quic_demo/src/bin/client_gui.rs
@@ -1,3 +1,5 @@
+use std::str::FromStr;
+
 use fltk::{
 	app,
 	button::Button, 
@@ -44,7 +46,9 @@ fn main () -> anyhow::Result <()> {
 	let mut y = margin;
 	
 	let frame_status;
+	let mut input_client_port;
 	let mut input_server_id;
+	let mut input_server_port;
 	let mut but_open;
 	let mut but_close;
 	
@@ -74,7 +78,7 @@ fn main () -> anyhow::Result <()> {
 	
 	{
 		let w = 80;
-		let mut input_client_port = Input::new (x, y, w, h, "");
+		input_client_port = Input::new (x, y, w, h, "");
 		x += w + margin;
 		
 		let w = 120;
@@ -82,7 +86,7 @@ fn main () -> anyhow::Result <()> {
 		x += w + margin;
 		
 		let w = 80;
-		let mut input_server_port = Input::new (x, y, w, h, "");
+		input_server_port = Input::new (x, y, w, h, "");
 		x += w + margin;
 		
 		let w = 80;
@@ -134,11 +138,19 @@ fn main () -> anyhow::Result <()> {
 		match fltk_rx.recv () {
 			Some (Message::OpenPort) => {
 				let connection_p2_p3 = connection_p2_p3.clone ();
-				let server_id = input_server_id.value ().to_string ();
+				let client_tcp_port = u16::from_str (&input_client_port.value ())?;
+				let server_id = input_server_id.value ();
+				let server_tcp_port = u16::from_str (&input_server_port.value ())?;
 				let (shutdown_flag, shutdown_flag_rx) = tokio::sync::watch::channel (true);
 				
 				let task = rt.spawn (async move {
-					forward_port (connection_p2_p3, server_id, shutdown_flag_rx).await
+					forward_port (
+						connection_p2_p3,
+						client_tcp_port,
+						server_id, 
+						server_tcp_port,
+						shutdown_flag_rx
+					).await
 				});
 				
 				forwarding_instance.replace (ForwardingInstance {
@@ -188,12 +200,12 @@ struct ForwardingInstance {
 
 async fn forward_port (
 	connection_p2_p3: quinn::Connection,
+	client_tcp_port: u16,
 	server_id: String,
+	server_tcp_port: u16,
 	shutdown_flag_rx: tokio::sync::watch::Receiver <bool>,
 ) -> anyhow::Result <()>
 {
-	let client_tcp_port = 30381;
-	let server_tcp_port = 30382;
 	let listener = TcpListener::bind (("127.0.0.1", client_tcp_port)).await?;
 	
 	trace! ("Accepting local TCP connections from P1 on {}", client_tcp_port);