diff --git a/pom.xml b/pom.xml
index c0cee74f..20b14cfc 100644
--- a/pom.xml
+++ b/pom.xml
@@ -20,6 +20,7 @@
     <revision>0.0.1</revision>
     <rlo_14.version>1.0.1</rlo_14.version>
     <rlp_01.version>4.0.1</rlp_01.version>
+    <rlp_03.version>6.0.0</rlp_03.version>
     <sha1></sha1>
   </properties>
   <dependencies>
@@ -113,6 +114,12 @@
       <version>${junit.version}</version>
       <scope>test</scope>
     </dependency>
+    <!-- relp server, testing -->
+    <dependency>
+      <groupId>com.teragrep</groupId>
+      <artifactId>rlp_03</artifactId>
+      <version>${rlp_03.version}</version>
+    </dependency>
     <!-- securemock, testing -->
     <dependency>
       <groupId>org.elasticsearch</groupId>
diff --git a/src/test/java/EndToEndTest.java b/src/test/java/EndToEndTest.java
new file mode 100644
index 00000000..7c876d5e
--- /dev/null
+++ b/src/test/java/EndToEndTest.java
@@ -0,0 +1,192 @@
+/*
+  logstash-http-input to syslog bridge
+  Copyright 2024 Suomen Kanuuna Oy
+
+  Derivative Work of Elasticsearch
+  Copyright 2012-2015 Elasticsearch
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+  http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+*/
+import com.teragrep.lsh_01.Main;
+import com.teragrep.lsh_01.config.NettyConfig;
+import com.teragrep.lsh_01.util.RelpServer;
+import org.junit.jupiter.api.*;
+
+import java.net.HttpURLConnection;
+import java.net.URI;
+import java.net.URL;
+import java.net.http.HttpClient;
+import java.net.http.HttpRequest;
+import java.net.http.HttpResponse;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Random;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.ExecutionException;
+
+@TestInstance(TestInstance.Lifecycle.PER_CLASS)
+public class EndToEndTest {
+
+    private RelpServer relpServer;
+    private NettyConfig nettyConfig;
+
+    @BeforeAll
+    void setUp() throws InterruptedException {
+        System.setProperty("payload.splitEnabled", "true");
+        System.setProperty("security.authRequired", "false");
+
+        // Start listening to HTTP-requests
+        Thread program = new Thread(() -> Main.main(new String[]{}));
+        program.start();
+
+        Thread.sleep(3000); // wait for netty to start up
+
+        this.relpServer = new RelpServer();
+        this.relpServer.setUp();
+
+        this.nettyConfig = new NettyConfig();
+    }
+
+    @AfterEach
+    void reset() {
+        this.relpServer.clear();
+    }
+
+    @AfterAll
+    void tearDown() {
+        System.clearProperty("payload.splitEnabled");
+        System.clearProperty("security.authRequired");
+        this.relpServer.tearDown();
+    }
+
+    @Test
+    public void testSplittingMessage1() throws InterruptedException, ExecutionException {
+        String requestBody = "foofoo\nbar";
+
+        HttpClient httpClient = HttpClient.newHttpClient();
+
+        HttpRequest request = HttpRequest
+                .newBuilder(URI.create("http://" + nettyConfig.listenAddress + ":" + nettyConfig.listenPort))
+                .POST(HttpRequest.BodyPublishers.ofString(requestBody))
+                .build();
+
+        CompletableFuture<HttpResponse<String>> response = httpClient
+                .sendAsync(request, HttpResponse.BodyHandlers.ofString());
+
+        Assertions.assertEquals(200, response.get().statusCode());
+
+        List<String> payloads = this.relpServer.payloads();
+
+        // assert that payload was correctly split into two
+        Assertions.assertEquals(2, payloads.size());
+        Assertions.assertTrue(payloads.get(0).contains("foofoo"));
+        Assertions.assertFalse(payloads.get(0).contains("bar"));
+        Assertions.assertTrue(payloads.get(1).contains("bar"));
+        Assertions.assertFalse(payloads.get(1).contains("foofoo"));
+    }
+
+    @Test
+    public void testSplittingMessage2() throws InterruptedException, ExecutionException {
+        String requestBody = "foofoo\nbar\nfoo bar";
+
+        HttpClient httpClient = HttpClient.newHttpClient();
+
+        HttpRequest request = HttpRequest
+                .newBuilder(URI.create("http://" + nettyConfig.listenAddress + ":" + nettyConfig.listenPort))
+                .POST(HttpRequest.BodyPublishers.ofString(requestBody))
+                .build();
+
+        CompletableFuture<HttpResponse<String>> response = httpClient
+                .sendAsync(request, HttpResponse.BodyHandlers.ofString());
+
+        Assertions.assertEquals(200, response.get().statusCode());
+
+        List<String> payloads = this.relpServer.payloads();
+
+        // assert that payload was correctly split into three parts
+        Assertions.assertEquals(3, payloads.size());
+        Assertions.assertTrue(payloads.get(0).contains("foofoo"));
+        Assertions.assertFalse(payloads.get(0).contains("bar"));
+        Assertions.assertTrue(payloads.get(1).contains("bar"));
+        Assertions.assertFalse(payloads.get(1).contains("foofoo"));
+        Assertions.assertTrue(payloads.get(2).contains("foo bar"));
+    }
+
+    @Test
+    public void testNullHeaders() {
+        /*
+            Have to use the old HttpURLConnection because HttpClient doesn't allow sending null headers.
+         */
+        Assertions.assertDoesNotThrow(() -> {
+            String listenAddress = nettyConfig.listenAddress;
+            if (listenAddress.equals("127.0.0.1")) {
+                // HttpURLConnection doesn't work with the IP.
+                listenAddress = "localhost";
+            }
+
+            URL url = new URL("http://" + listenAddress + ":" + nettyConfig.listenPort);
+            HttpURLConnection connection = (HttpURLConnection) url.openConnection();
+            connection.setRequestMethod("POST");
+
+            connection.setRequestProperty("Content-Type", null);
+
+            Assertions.assertEquals(200, connection.getResponseCode());
+        });
+
+        List<String> payloads = relpServer.payloads();
+        Assertions.assertEquals(1, payloads.size());
+        Assertions.assertTrue(payloads.get(0).contains("content_type=\"\"")); // not null but empty string
+    }
+
+    @Test
+    public void testMultipleRequests() throws ExecutionException, InterruptedException {
+        ArrayList<String> requestBodies = new ArrayList<>();
+
+        HttpClient httpClient = HttpClient.newHttpClient();
+
+        for (int i = 0; i < 100; i++) {
+            String requestBody = randomString();
+            requestBodies.add(requestBody);
+
+            HttpRequest request = HttpRequest
+                    .newBuilder(URI.create("http://" + nettyConfig.listenAddress + ":" + nettyConfig.listenPort))
+                    .POST(HttpRequest.BodyPublishers.ofString(requestBody))
+                    .build();
+
+            CompletableFuture<HttpResponse<String>> response = httpClient
+                    .sendAsync(request, HttpResponse.BodyHandlers.ofString());
+
+            Assertions.assertEquals(200, response.get().statusCode());
+        }
+
+        List<String> payloads = this.relpServer.payloads();
+
+        Assertions.assertEquals(100, payloads.size());
+        for (int i = 0; i < payloads.size(); i++) {
+            Assertions.assertTrue(payloads.get(i).contains(requestBodies.get(i))); // all message bodies are correct
+        }
+    }
+
+    private String randomString() {
+        int leftLimit = 97; // letter 'a'
+        int rightLimit = 122; // letter 'z'
+        int targetStringLength = 10;
+        Random random = new Random();
+
+        return random
+                .ints(leftLimit, rightLimit + 1)
+                .limit(targetStringLength)
+                .collect(StringBuilder::new, StringBuilder::appendCodePoint, StringBuilder::append)
+                .toString();
+    }
+}
diff --git a/src/test/java/com/teragrep/lsh_01/util/RelpServer.java b/src/test/java/com/teragrep/lsh_01/util/RelpServer.java
new file mode 100644
index 00000000..7928524d
--- /dev/null
+++ b/src/test/java/com/teragrep/lsh_01/util/RelpServer.java
@@ -0,0 +1,143 @@
+/*
+  logstash-http-input to syslog bridge
+  Copyright 2024 Suomen Kanuuna Oy
+
+  Derivative Work of Elasticsearch
+  Copyright 2012-2015 Elasticsearch
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+  http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+*/
+package com.teragrep.lsh_01.util;
+
+import com.teragrep.lsh_01.config.RelpConfig;
+import com.teragrep.rlp_03.channel.socket.PlainFactory;
+import com.teragrep.rlp_03.eventloop.EventLoop;
+import com.teragrep.rlp_03.eventloop.EventLoopFactory;
+import com.teragrep.rlp_03.frame.delegate.DefaultFrameDelegate;
+import com.teragrep.rlp_03.frame.delegate.FrameContext;
+import com.teragrep.rlp_03.frame.delegate.FrameDelegate;
+import com.teragrep.rlp_03.server.ServerFactory;
+
+import java.io.IOException;
+import java.io.UncheckedIOException;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.function.Consumer;
+import java.util.function.Supplier;
+
+public class RelpServer {
+
+    private EventLoop eventLoop;
+    private Thread eventLoopThread;
+    private final int listenPort;
+    private final ExecutorService executorService;
+
+    private final List<String> payloads;
+
+    public RelpServer() {
+        RelpConfig relpConfig = new RelpConfig();
+        this.listenPort = relpConfig.relpPort;
+        this.payloads = new ArrayList<>();
+
+        int threads = 1;
+        this.executorService = Executors.newFixedThreadPool(threads);
+    }
+
+    /**
+     * Set up the server before running end-to-end tests.
+     */
+    public void setUp() {
+        Consumer<FrameContext> syslogConsumer = new Consumer<>() {
+
+            // NOTE: synchronized because frameDelegateSupplier returns this instance for all the parallel connections
+            @Override
+            public synchronized void accept(FrameContext frameContext) {
+                payloads.add(frameContext.relpFrame().payload().toString());
+            }
+        };
+
+        /*
+         * DefaultFrameDelegate accepts Consumer<FrameContext> for processing syslog frames
+         */
+        Supplier<FrameDelegate> frameDelegateSupplier = () -> new DefaultFrameDelegate(syslogConsumer);
+
+        /*
+         * EventLoop is used to notice any events from the connections
+         */
+        EventLoopFactory eventLoopFactory = new EventLoopFactory();
+        try {
+            eventLoop = eventLoopFactory.create();
+        }
+        catch (IOException e) {
+            throw new RuntimeException(e);
+        }
+
+        eventLoopThread = new Thread(eventLoop);
+        /*
+         * eventLoopThread must run, otherwise nothing will be processed
+         */
+        eventLoopThread.start();
+
+        /*
+         * ServerFactory is used to create server instances
+         */
+        ServerFactory serverFactory = new ServerFactory(
+                eventLoop,
+                executorService,
+                new PlainFactory(),
+                frameDelegateSupplier
+        );
+
+        try {
+            serverFactory.create(listenPort);
+        }
+        catch (IOException ioException) {
+            throw new UncheckedIOException(ioException);
+        }
+    }
+
+    /**
+     * Close the server after tests.
+     */
+    public void tearDown() {
+        /*
+         * Stop eventLoop
+         */
+        eventLoop.stop();
+
+        /*
+         * Wait for stop to complete
+         */
+        try {
+            eventLoopThread.join();
+        }
+        catch (InterruptedException interruptedException) {
+            throw new RuntimeException(interruptedException);
+        }
+
+        executorService.shutdown();
+    }
+
+    /**
+     * Clear payloads in between tests
+     */
+    public void clear() {
+        payloads.clear();
+    }
+
+    public List<String> payloads() {
+        return payloads;
+    }
+}