diff --git a/S7.Net.UnitTest/CommunicationTests/ConnectionOpen.cs b/S7.Net.UnitTest/CommunicationTests/ConnectionOpen.cs
new file mode 100644
index 0000000..d19f7c3
--- /dev/null
+++ b/S7.Net.UnitTest/CommunicationTests/ConnectionOpen.cs
@@ -0,0 +1,127 @@
+using System.Net;
+using System.Threading.Tasks;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using S7.Net.Protocol;
+
+namespace S7.Net.UnitTest.CommunicationTests;
+
+[TestClass]
+public class ConnectionOpen
+{
+    [TestMethod]
+    public async Task Does_Not_Throw()
+    {
+        var cs = new CommunicationSequence {
+            {
+                """
+                    // TPKT
+                    03 // Version
+                    00 // Reserved
+                    00 16 // Length
+
+                    // CR
+                    11 // Number of bytes following
+                    E0 // CR / Credit
+                    00 00 // Destination reference, unused
+                    __ __ // Source reference, unused
+                    00 // Class / Option
+
+                    // Source TSAP
+                    C1 // Parameter code
+                    02 // Parameter length
+                    TSAP_SRC_CHAN // Channel
+                    TSAP_SRC_POS // Position
+
+                    // Destination TSAP
+                    C2 // Parameter code
+                    02 // Parameter length
+                    TSAP_DEST_CHAN // Channel
+                    TSAP_DEST_POS // Position
+
+                    // PDU Size parameter
+                    C0 // Parameter code
+                    01 // Parameter length
+                    0A // 1024 byte PDU (2 ^ 10)
+                """,
+                """
+                    // TPKT
+                    03 // Version
+                    00 // Reserved
+                    00 0B // Length
+
+                    // CC
+                    06 // Length
+                    D0 // CC / Credit
+                    00 00 // Destination reference
+                    00 00 // Source reference
+                    00 // Class / Option
+                """
+            },
+            {
+                """
+                    // TPKT
+                    03 // Version
+                    00 // Reserved
+                    00 19 // Length
+
+                    // Data header
+                    02 // Length
+                    F0 // Data identifier
+                    80 // PDU number and end of transmission
+
+                    // S7 header
+                    32 // Protocol ID
+                    01 // Message type job request
+                    00 00 // Reserved
+                    PDU1 PDU2 // PDU reference
+                    00 08 // Parameter length (Communication Setup)
+                    00 00 // Data length
+
+                    // Communication Setup
+                    F0 // Function code
+                    00 // Reserved
+                    00 03 // Max AMQ caller
+                    00 03 // Max AMQ callee
+                    03 C0 // PDU size (960)
+                """,
+                """
+                    // TPKT
+                    03 // Version
+                    00 // Reserved
+                    00 1B // Length
+
+                    // Data header
+                    02 // Length
+                    F0 // Data identifier
+                    80 // PDU number and end of transmission
+
+                    // S7 header
+                    32 // Protocol ID
+                    03 // Message type ack data
+                    00 00 // Reserved
+                    PDU1 PDU2 // PDU reference
+                    00 08 // Parameter length (Communication Setup)
+                    00 00 // Data length
+                    00 // Error class
+                    00 // Error code
+
+                    // Communication Setup
+                    F0 // Function code
+                    00 // Reserved
+                    00 03 // Max AMQ caller
+                    00 03 // Max AMQ callee
+                    03 C0 // PDU size (960)
+                """
+            }
+        };
+
+        async Task Client(int port)
+        {
+            var conn = new Plc(IPAddress.Loopback.ToString(), port, new TsapPair(new Tsap(1, 2), new Tsap(3, 4)));
+            await conn.OpenAsync();
+            conn.Close();
+        }
+
+        await Task.WhenAll(cs.Serve(out var port), Client(port));
+    }
+}
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