diff --git a/substrate/core/network-libp2p/tests/test.rs b/substrate/core/network-libp2p/tests/test.rs
index 8120e15c3a..5ff4255965 100644
--- a/substrate/core/network-libp2p/tests/test.rs
+++ b/substrate/core/network-libp2p/tests/test.rs
@@ -14,41 +14,44 @@
 // You should have received a copy of the GNU General Public License
 // along with Substrate.  If not, see <http://www.gnu.org/licenses/>.
 
-use futures::{future, prelude::*, try_ready};
+use futures::{future, stream, prelude::*, try_ready};
 use std::{io, iter};
 use substrate_network_libp2p::{ServiceEvent, multiaddr};
 
-/// Builds two services. The second one has the first one as its bootstrap node.
+/// Builds two services. The second one and further have the first one as its bootstrap node.
 /// This is to be used only for testing, and a panic will happen if something goes wrong.
-fn build_two_nodes() -> (substrate_network_libp2p::Service, substrate_network_libp2p::Service) {
-	let service1 = {
-		let config = substrate_network_libp2p::NetworkConfiguration {
-			listen_addresses: vec![multiaddr![Ip4([127, 0, 0, 1]), Tcp(0u16)]],
-			..substrate_network_libp2p::NetworkConfiguration ::default()
-		};
-		let proto = substrate_network_libp2p::RegisteredProtocol::new(*b"tst", &[1]);
-		substrate_network_libp2p::start_service(config, iter::once(proto)).unwrap()
-	};
+fn build_nodes(num: usize) -> Vec<substrate_network_libp2p::Service> {
+	let mut result: Vec<substrate_network_libp2p::Service> = Vec::with_capacity(num);
 
-	let service2 = {
-		let mut bootnode = service1.listeners().next().unwrap().clone();
-		bootnode.append(libp2p::multiaddr::Protocol::P2p(service1.peer_id().clone().into()));
+	for _ in 0 .. num {
+		let mut boot_nodes = Vec::new();
+		if !result.is_empty() {
+			let mut bootnode = result[0].listeners().next().unwrap().clone();
+			bootnode.append(libp2p::multiaddr::Protocol::P2p(result[0].peer_id().clone().into()));
+			boot_nodes.push(bootnode.to_string());
+		}
 
 		let config = substrate_network_libp2p::NetworkConfiguration {
 			listen_addresses: vec![multiaddr![Ip4([127, 0, 0, 1]), Tcp(0u16)]],
-			boot_nodes: vec![bootnode.to_string()],
+			boot_nodes,
 			..substrate_network_libp2p::NetworkConfiguration::default()
 		};
-		let proto = substrate_network_libp2p::RegisteredProtocol::new(*b"tst", &[1]);
-		substrate_network_libp2p::start_service(config, iter::once(proto)).unwrap()
-	};
 
-	(service1, service2)
+		let proto = substrate_network_libp2p::RegisteredProtocol::new(*b"tst", &[1]);
+		result.push(substrate_network_libp2p::start_service(config, iter::once(proto)).unwrap());
+	}
+
+	result
 }
 
 #[test]
 fn basic_two_nodes_connectivity() {
-	let (mut service1, mut service2) = build_two_nodes();
+	let (mut service1, mut service2) = {
+		let mut l = build_nodes(2).into_iter();
+		let a = l.next().unwrap();
+		let b = l.next().unwrap();
+		(a, b)
+	};
 
 	let fut1 = future::poll_fn(move || -> io::Result<_> {
 		match try_ready!(service1.poll()) {
@@ -75,3 +78,103 @@ fn basic_two_nodes_connectivity() {
 	let combined = fut1.select(fut2).map_err(|(err, _)| err);
 	tokio::runtime::Runtime::new().unwrap().block_on_all(combined).unwrap();
 }
+
+#[test]
+fn two_nodes_transfer_lots_of_packets() {
+	// We spawn two nodes, then make the first one send lots of packets to the second one. The test
+	// ends when the second one has received all of them.
+	const NUM_PACKETS: u32 = 20000;
+
+	let (mut service1, mut service2) = {
+		let mut l = build_nodes(2).into_iter();
+		let a = l.next().unwrap();
+		let b = l.next().unwrap();
+		(a, b)
+	};
+
+	let fut1 = future::poll_fn(move || -> io::Result<_> {
+		loop {
+			match try_ready!(service1.poll()) {
+				Some(ServiceEvent::OpenedCustomProtocol { node_index, protocol, .. }) => {
+					for n in 0 .. NUM_PACKETS {
+						service1.send_custom_message(node_index, protocol, vec![(n % 256) as u8]);
+					}
+				},
+				_ => panic!(),
+			}
+		}
+	});
+
+	let mut packet_counter = 0u32;
+	let fut2 = future::poll_fn(move || -> io::Result<_> {
+		loop {
+			match try_ready!(service2.poll()) {
+				Some(ServiceEvent::OpenedCustomProtocol { .. }) => {},
+				Some(ServiceEvent::CustomMessage { data, .. }) => {
+					assert_eq!(data.len(), 1);
+					assert_eq!(u32::from(data[0]), packet_counter % 256);
+					packet_counter += 1;
+					if packet_counter == NUM_PACKETS {
+						return Ok(Async::Ready(()))
+					}
+				}
+				_ => panic!(),
+			}
+		}
+	});
+
+	let combined = fut1.select(fut2).map_err(|(err, _)| err);
+	tokio::runtime::Runtime::new().unwrap().block_on_all(combined).unwrap();
+}
+
+#[test]
+fn many_nodes_connectivity() {
+	// Creates many nodes, then make sure that they are all connected to each other.
+	// Note: if you increase this number, keep in mind that there's a limit to the number of
+	// simultaneous connections which will make the test fail if it is reached. This can be
+	// increased in the `NetworkConfiguration`.
+	const NUM_NODES: usize = 25;
+
+	let mut futures = build_nodes(NUM_NODES)
+		.into_iter()
+		.map(move |mut node| {
+			let mut num_connecs = 0;
+			stream::poll_fn(move || -> io::Result<_> {
+				loop {
+					match try_ready!(node.poll()) {
+						Some(ServiceEvent::OpenedCustomProtocol { .. }) => {
+							num_connecs += 1;
+							if num_connecs == NUM_NODES - 1 {
+								return Ok(Async::Ready(Some(())))
+							}
+						}
+						// TODO: we sometimes receive a closed connection event; maybe this is
+						//	benign, but it would be nice to figure out why
+						//	(https://github.com/libp2p/rust-libp2p/issues/844)
+						Some(ServiceEvent::ClosedCustomProtocol { .. }) => {}
+						_ => panic!(),
+					}
+				}
+			})
+		})
+		.collect::<Vec<_>>();
+
+	let mut successes = 0;
+	let combined = future::poll_fn(move || -> io::Result<_> {
+		for node in futures.iter_mut() {
+			match node.poll()? {
+				Async::Ready(Some(_)) => successes += 1,
+				Async::Ready(None) => unreachable!(),
+				Async::NotReady => ()
+			}
+		}
+
+		if successes == NUM_NODES {
+			Ok(Async::Ready(()))
+		} else {
+			Ok(Async::NotReady)
+		}
+	});
+
+	tokio::runtime::Runtime::new().unwrap().block_on(combined).unwrap();
+}