diff --git a/prototypes/quic_demo/src/bin/quic_demo_client.rs b/prototypes/quic_demo/src/bin/quic_demo_client.rs
index fd60706..d453acc 100644
--- a/prototypes/quic_demo/src/bin/quic_demo_client.rs
+++ b/prototypes/quic_demo/src/bin/quic_demo_client.rs
@@ -2,6 +2,7 @@ use structopt::StructOpt;
 use tokio::net::TcpListener;
 
 use quic_demo::prelude::*;
+use protocol::PeerId;
 
 #[derive (Debug, StructOpt)]
 struct Opt {
@@ -10,9 +11,9 @@ struct Opt {
 	#[structopt (long)]
 	local_tcp_port: Option <u16>,
 	#[structopt (long)]
-	client_id: Option <u8>,
+	client_id: Option <PeerId>,
 	#[structopt (long)]
-	server_id: Option <u8>,
+	server_id: Option <PeerId>,
 }
 
 #[tokio::main]
diff --git a/prototypes/quic_demo/src/bin/quic_demo_end_server.rs b/prototypes/quic_demo/src/bin/quic_demo_end_server.rs
index 6bd0f47..40f95c9 100644
--- a/prototypes/quic_demo/src/bin/quic_demo_end_server.rs
+++ b/prototypes/quic_demo/src/bin/quic_demo_end_server.rs
@@ -2,6 +2,7 @@ use structopt::StructOpt;
 use tokio::net::TcpStream;
 
 use quic_demo::prelude::*;
+use protocol::PeerId;
 
 #[derive (Debug, StructOpt)]
 struct Opt {
@@ -10,7 +11,7 @@ struct Opt {
 	#[structopt (long)]
 	local_tcp_port: Option <u16>,
 	#[structopt (long)]
-	server_id: Option <u8>,
+	server_id: Option <PeerId>,
 }
 
 #[tokio::main]
@@ -62,7 +63,7 @@ async fn handle_new_ptth_connection (
 	mut relay_send: quinn::SendStream,
 	mut relay_recv: quinn::RecvStream,
 	local_tcp_port: u16,
-	_client_id: u8,
+	_client_id: PeerId,
 ) -> anyhow::Result <()>
 {
 	// TODO: Check authorization for P2 --> P4
diff --git a/prototypes/quic_demo/src/bin/quic_demo_relay_server.rs b/prototypes/quic_demo/src/bin/quic_demo_relay_server.rs
index 00d174f..5d95519 100644
--- a/prototypes/quic_demo/src/bin/quic_demo_relay_server.rs
+++ b/prototypes/quic_demo/src/bin/quic_demo_relay_server.rs
@@ -1,6 +1,7 @@
 use structopt::StructOpt;
 
 use quic_demo::prelude::*;
+use protocol::PeerId;
 
 #[derive (Debug, StructOpt)]
 struct Opt {
@@ -45,7 +46,7 @@ async fn main () -> anyhow::Result <()> {
 
 #[derive (Default)]
 struct RelayState {
-	p4_server_proxies: Mutex <HashMap <u8, P4State>>,
+	p4_server_proxies: Mutex <HashMap <PeerId, P4State>>,
 	stats: Stats,
 }
 
@@ -92,7 +93,7 @@ impl RelayState {
 struct RequestP2ToP4 {
 	client_send: quinn::SendStream,
 	client_recv: quinn::RecvStream,
-	client_id: u8,
+	client_id: PeerId,
 }
 
 struct PtthNewConnection {
@@ -227,8 +228,8 @@ async fn handle_p2_connection (
 
 async fn handle_request_p2_to_p4 (
 	relay_state: Arc <RelayState>,
-	client_id: u8,
-	server_id: u8,
+	client_id: PeerId,
+	server_id: PeerId,
 	mut client_send: quinn::SendStream,
 	client_recv: quinn::RecvStream,
 ) -> anyhow::Result <()>
diff --git a/prototypes/quic_demo/src/protocol.rs b/prototypes/quic_demo/src/protocol.rs
index 1d79481..8c21f78 100644
--- a/prototypes/quic_demo/src/protocol.rs
+++ b/prototypes/quic_demo/src/protocol.rs
@@ -6,6 +6,8 @@ use quinn::{
 
 use crate::prelude::*;
 
+pub type PeerId = u8;
+
 #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
 pub struct Command (pub u8);
 
@@ -21,7 +23,7 @@ impl Command {
 pub async fn p2_connect_to_p3 (
 	endpoint: &quinn::Endpoint,
 	relay_addr: &std::net::SocketAddr,
-	client_id: u8,
+	client_id: PeerId,
 ) -> Result <quinn::NewConnection> 
 {
 	let new_conn = endpoint.connect (relay_addr, "localhost")?.await?;
@@ -38,7 +40,7 @@ pub async fn p2_connect_to_p3 (
 
 pub async fn p2_connect_to_p5 (
 	connection: &quinn::Connection,
-	server_id: u8,
+	server_id: PeerId,
 ) -> Result <(SendStream, RecvStream)>
 {
 	let (mut send, mut recv) = connection.open_bi ().await?;
@@ -70,11 +72,11 @@ pub enum P3Peer {
 }
 
 pub struct P2ClientProxy {
-	pub id: u8,
+	pub id: PeerId,
 }
 
 pub struct P4ServerProxy {
-	pub id: u8,
+	pub id: PeerId,
 }
 
 pub async fn p3_accept_peer (
@@ -122,7 +124,7 @@ pub async fn p3_authorize_p4_peer (
 
 pub async fn p3_connect_p2_to_p4 (
 	connection: &quinn::Connection,
-	client_id: u8,
+	client_id: PeerId,
 ) -> Result <(SendStream, RecvStream)>
 {
 	let (mut send, mut recv) = connection.open_bi ().await?;
@@ -145,7 +147,7 @@ pub async fn p3_connect_p2_to_p4 (
 
 pub enum P2ToP3Stream {
 	ConnectP2ToP4 {
-		server_id: u8,
+		server_id: PeerId,
 	},
 }
 
@@ -177,7 +179,7 @@ pub async fn p3_authorize_p2_to_p4_connection (
 pub async fn p4_connect_to_p3 (
 	endpoint: &quinn::Endpoint,
 	relay_addr: &std::net::SocketAddr,
-	server_id: u8,
+	server_id: PeerId,
 ) -> Result <quinn::NewConnection> 
 {
 	let new_conn = endpoint.connect (relay_addr, "localhost")?.await?;
@@ -194,7 +196,7 @@ pub async fn p4_connect_to_p3 (
 
 pub enum P3ToP4Stream {
 	NewPtthConnection {
-		client_id: u8,
+		client_id: PeerId,
 	}
 }
 
@@ -271,3 +273,5 @@ async fn expect_exact_response (
 	
 	Ok (())
 }
+
+