diff --git a/src/main/scala/Demo.scala b/src/main/scala/Demo.scala
deleted file mode 100644
index fe77db8..0000000
--- a/src/main/scala/Demo.scala
+++ /dev/null
@@ -1,81 +0,0 @@
-import java.io.File
-
-import akka.{Done, NotUsed}
-import akka.actor.ActorSystem
-import akka.stream.{ClosedShape, ThrottleMode, IOResult, ActorMaterializer}
-import akka.stream.scaladsl._
-import akka.util.ByteString
-
-import scala.concurrent.Future
-import scala.concurrent.duration._
-
-object Demo extends App {
-
-  implicit val system = ActorSystem("Demo")
-  implicit val materializer = ActorMaterializer()
-
-  val source: Source[Int, NotUsed] = Source(1 to 100)
-  source.runForeach(i => println(i))
-
-  val factorials = source.scan(BigInt(1))((acc, next) => acc * next)
-
-  val result: Future[IOResult] = factorials
-    .map(num => ByteString(s"$num\n"))
-    .runWith(FileIO.toFile(new File("factorials.txt")))
-
-  def lineSink(fileName: String): Sink[String, Future[IOResult]] = {
-    Flow[String]
-      .map(s => ByteString(s + "\n"))
-      .toMat(FileIO.toFile(new File(fileName)))(Keep.right)
-  }
-
-  factorials.map(_.toString).runWith(lineSink("factorial2.txt"))
-
-//  val done =
-//   factorials
-//    .zipWith(Source(0 to 100))((num, idx) => s"$idx! = $num")
-//    .throttle(1, 1.second, 1, ThrottleMode.shaping)
-//    .runForeach(println)
-
-  val source2 = Source(1 to 10)
-  val sink = Sink.fold[Int, Int](0)(_ + _)
-
-  sink.runWith(source2)
-
-  import system.dispatcher
-  source2.runWith(Sink.head).onComplete(println(_))
-
-  import akka.stream.Fusing
-
-  val flow = Flow[Int].map(_ * 2).filter(_ > 500)
-  val fused = Fusing.aggressive(flow)
-
-  val fusedSource =
-  Source.fromIterator { () => Iterator from 0 }
-    .via(fused)
-    .take(1000)
-
-//  fusedSource.runForeach(i => println(i))
-
-
-  val g = RunnableGraph.fromGraph(GraphDSL.create() { implicit builder =>
-    import GraphDSL.Implicits._
-
-    val in = Source(1 to 10)
-    val out: Sink[Any, Future[Done]] = Sink.foreach(println(_))
-
-    val bcast = builder.add(Broadcast[Int](2))
-    val merge = builder.add(Merge[Int](2))
-
-    val f1 = Flow[Int].map(_ * 2)
-    val f2 = Flow[Int].map(_ + 1)
-    val f4 = Flow[Int].map(_ * 10)
-    val f3 = Flow[Int].map(i => i)
-
-    in ~> f1 ~> bcast ~> f2 ~> merge ~> f3 ~> out
-                bcast ~> f4 ~> merge
-    ClosedShape
-  })
-
-  g.run()
-}
diff --git a/src/main/scala/EchoServer.scala b/src/main/scala/EchoServer.scala
deleted file mode 100644
index c8cae6a..0000000
--- a/src/main/scala/EchoServer.scala
+++ /dev/null
@@ -1,45 +0,0 @@
-import akka.actor.ActorSystem
-import akka.stream.ActorMaterializer
-import akka.stream.scaladsl.Tcp.{IncomingConnection, ServerBinding}
-import akka.stream.scaladsl._
-import akka.util.ByteString
-
-import scala.concurrent.Future
-
-object EchoServer extends App {
-
-//  val binding: Future[ServerBinding] =
-//    Tcp().bind("127.0.0.1", 8888).to(Sink.ignore).run()
-//
-//  binding.map { b =>
-//    b.unbind() onComplete {
-//      case _ => // ...
-//    }
-//  }
-
-  implicit val system = ActorSystem("echo-server")
-  implicit val materializer = ActorMaterializer()
-
-  val connections: Source[IncomingConnection, Future[ServerBinding]] =
-    Tcp().bind("127.0.0.1", 8888)
-
-  connections runForeach { incomingConnection =>
-    println(s"New connection from: ${incomingConnection.remoteAddress}")
-
-    val echo = Flow[ByteString]
-      .via(Framing.delimiter(
-        ByteString("\n"),
-        maximumFrameLength = 256,
-        allowTruncation = true))
-      .map(_.utf8String)
-      .map(_ + "!!!\n")
-      .map(ByteString(_))
-
-    val echo2 = Flow[ByteString]
-      .map(_.utf8String)
-      .map("Echo " + _)
-      .map(ByteString(_))
-
-    incomingConnection.handleWith(echo2)
-  }
-}
diff --git a/src/main/scala/Join.scala b/src/main/scala/Join.scala
deleted file mode 100644
index 113b91a..0000000
--- a/src/main/scala/Join.scala
+++ /dev/null
@@ -1,27 +0,0 @@
-import java.io.File
-
-import akka.actor.ActorSystem
-import akka.stream.scaladsl._
-import akka.stream.{ActorMaterializer, ClosedShape, IOResult}
-import akka.util.ByteString
-import akka.{Done, NotUsed}
-
-import scala.concurrent.Future
-
-object Join extends App {
-
-  implicit val system = ActorSystem("Demo")
-  implicit val materializer = ActorMaterializer()
-
-  val source: Source[Int, NotUsed] = Source(1 to 100)
-
-  val f1: Flow[Int, Int, NotUsed] = Flow[Int].map(_ * 2)
-  val f2: Flow[Int, Int, NotUsed] = Flow[Int].map(_ * 5)
-
-  val joined: RunnableGraph[NotUsed] = f1.join(f2)
-
-//  joined.
-    //.runForeach(i => println(i))
-
-
-}
diff --git a/src/main/scala/Map.scala b/src/main/scala/Map.scala
deleted file mode 100644
index 4d3fc97..0000000
--- a/src/main/scala/Map.scala
+++ /dev/null
@@ -1,15 +0,0 @@
-import akka.actor.ActorSystem
-import akka.stream.ActorMaterializer
-import akka.stream.scaladsl.{Source, Flow}
-import akka.util.ByteString
-
-object Map extends App {
-
-  implicit val system = ActorSystem("Demo")
-  implicit val materializer = ActorMaterializer()
-
-  val f1: Flow[Int, String, _] = Flow[Int].map(_.toString)
-//  val f2: Flow[Int, Int, _] = f1.map(_.toInt)
-
-  Source(1 to 100).via(f1).runForeach(x => println(x))
-}
diff --git a/src/main/scala/Maybe.scala b/src/main/scala/Maybe.scala
deleted file mode 100644
index 3384ca2..0000000
--- a/src/main/scala/Maybe.scala
+++ /dev/null
@@ -1,31 +0,0 @@
-import akka.NotUsed
-import akka.actor.ActorSystem
-import akka.stream.ActorMaterializer
-import akka.stream.scaladsl.{Keep, Sink, Flow, Source}
-
-import scala.concurrent.{Future, Promise}
-
-object Maybe extends App {
-
-  implicit val system = ActorSystem("Demo")
-  implicit val materializer = ActorMaterializer()
-  import system.dispatcher
-
-  val f1: Flow[Int, String, NotUsed] =
-    Flow[Int]
-//      .map { elem => println(elem); elem }
-      .map(_.toString)
-
-  val source: Source[Int, Promise[Option[Int]]] = Source.maybe[Int]
-  val sink: Sink[String, Future[String]] = Sink.head[String]
-
-//  val (promise, fut) = source.via(f1).toMat(sink)(Keep.both).run()
-
-  val (promise, fut) = Source.maybe[Int].toMat(Sink.foreach(println))(Keep.both).run()
-
-  promise.completeWith(fut.map { x => println("completed biatch"); Some(1) })
-//  fut.map { x => println("Fut: " + x); x}
-
-//  promise.success(Some(5))
-
-}
diff --git a/src/main/scala/Protocol.scala b/src/main/scala/Protocol.scala
index 48dd768..e124d65 100644
--- a/src/main/scala/Protocol.scala
+++ b/src/main/scala/Protocol.scala
@@ -1,3 +1,4 @@
+import akka.NotUsed
 import akka.actor.ActorSystem
 import akka.stream.ActorMaterializer
 import akka.stream.scaladsl.Tcp.{IncomingConnection, ServerBinding}
@@ -5,33 +6,44 @@ import akka.stream.scaladsl._
 import akka.util.ByteString
 import com.typesafe.config.ConfigFactory
 
-import scala.concurrent.Future
+import scala.concurrent.{Promise, Future}
 
+/**
+  * Basis for a unidirectional TCP protocol
+  */
 object Protocol extends App {
 
   implicit val system = ActorSystem("unidirectional-tcp", ConfigFactory.defaultReference())
   implicit val materializer = ActorMaterializer()
-  import system.dispatcher
 
-  val binding: Source[IncomingConnection, Future[ServerBinding]] = Tcp().bind("localhost", 8888)
+  val binding: Source[IncomingConnection, Future[ServerBinding]] =
+    Tcp().bind("localhost", 8888)
 
   binding.runForeach { (incomingConnection: IncomingConnection) =>
     println(s"New connection from: ${incomingConnection.remoteAddress}")
 
+    // Sink can be swapped by f.i. an ActorSubscriber
+    val targetSink = Sink.foreach[String](e => println("Sink received: " + e))
+
+    val completionSource: Source[ByteString, Promise[Option[ByteString]]] =
+      Source.maybe[ByteString].drop(1) // Discard the element immediately, only used for closing connection
+
     val (closePromise, doneFuture) =
-      Source.maybe[ByteString]
+      completionSource
         .via(incomingConnection.flow)
-        .via(incoming)
-        .toMat(Sink.foreach(println))(Keep.both).run()
+        .via(protocol)
+        .toMat(targetSink)(Keep.both) // We keep both, because we use the future to complete the promise
+        .run()
 
-    // How is this promise completed???
+    // Completing the promise closes the connection
+    import system.dispatcher // Execution context for promise
     closePromise.completeWith(doneFuture.map { _ =>
-      Some(ByteString.empty)
+      Some(ByteString.empty) // Dummy element, will be dropped anyway
     })
   }
 
   // Simple flow mapping ByteStrings to Strings
-  val incoming: Flow[ByteString, String, _] =
+  val protocol: Flow[ByteString, String, _] =
     Flow[ByteString].map(_.utf8String)
 
 }