diff --git a/test/FritzCallMonitor.Tests/CallMonitorClientTest.cs b/test/FritzCallMonitor.Tests/CallMonitorClientTest.cs
new file mode 100644
index 0000000..6c70e14
--- /dev/null
+++ b/test/FritzCallMonitor.Tests/CallMonitorClientTest.cs
@@ -0,0 +1,142 @@
+using System;
+using System.Collections.Generic;
+using System.Reflection;
+using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
+using AMWD.Net.Api.Fritz.CallMonitor;
+using AMWD.Net.Api.Fritz.CallMonitor.Utils;
+using AMWD.Net.Api.Fritz.CallMonitor.Wrappers;
+using Microsoft.Extensions.Logging;
+using Moq;
+
+namespace FritzCallMonitor.Tests
+{
+	[TestClass]
+	public class CallMonitorClientTest
+	{
+		private const string HOST = "localhost";
+		private const int PORT = 1012;
+
+		private Mock<ReconnectTcpClient> _tcpClientMock;
+		private Mock<NetworkStreamWrapper> _networkStreamMock;
+
+		private Queue<(int DelaySeconds, byte[] BufferResponse)> _readAsyncResponses;
+
+		[TestInitialize]
+		public void Initialize()
+		{
+			_readAsyncResponses = new Queue<(int, byte[])>();
+
+			_readAsyncResponses.Enqueue((0, Encoding.UTF8.GetBytes("25.08.25 20:15:30;RING;2;012345678901;9876543;SIP0;\r\n")));
+			_readAsyncResponses.Enqueue((Timeout.Infinite, Array.Empty<byte>()));
+		}
+
+		[TestMethod]
+		public void ShouldCreateInstance()
+		{
+			// Arrange & Act
+			using var client = new CallMonitorClient(HOST, PORT);
+
+			// Assert
+			Assert.IsNotNull(client);
+		}
+
+		[TestMethod]
+		[DataRow(null)]
+		[DataRow("")]
+		[DataRow("   ")]
+		public void ShouldThrowArgumentNullExceptionOnMissingHost(string host)
+		{
+			// Arrange, Act & Assert
+			Assert.ThrowsExactly<ArgumentNullException>(() => new CallMonitorClient(host, PORT));
+		}
+
+		[TestMethod]
+		[DataRow(0)]
+		[DataRow(65536)]
+		public void ShouldThrowArgumentOutOfRangeExceptionOnInvalidPort(int port)
+		{
+			// Arrange, Act & Assert
+			Assert.ThrowsExactly<ArgumentOutOfRangeException>(() => new CallMonitorClient(HOST, port));
+		}
+
+		[TestMethod]
+		public void ShouldSetAndGetLogger()
+		{
+			// Arrange
+			var loggerMock = new Mock<ILogger>();
+			var client = GetClient();
+
+			// Act
+			client.Logger = loggerMock.Object;
+
+			// Assert
+			Assert.AreEqual(loggerMock.Object, client.Logger);
+
+			_tcpClientMock.VerifySet(m => m.Logger = loggerMock.Object, Times.Once);
+			_tcpClientMock.VerifyGet(m => m.IsConnected, Times.Once);
+			_tcpClientMock.Verify(m => m.GetStream(), Times.Once);
+
+			VerifyNoOtherCalls();
+		}
+
+		[TestMethod]
+		public void ShouldDisposeOnlyOnce()
+		{
+			// Arrange
+			var client = GetClient();
+
+			// Act
+			client.Dispose();
+			client.Dispose();
+
+			// Assert
+			_tcpClientMock.Verify(c => c.Dispose(), Times.Once);
+			_tcpClientMock.Verify(m => m.GetStream(), Times.Once);
+
+			VerifyNoOtherCalls();
+		}
+
+		private void VerifyNoOtherCalls()
+		{
+			_tcpClientMock.Verify(m => m.OnConnected, Times.Once);
+			_tcpClientMock.VerifyNoOtherCalls();
+		}
+
+		private CallMonitorClient GetClient()
+		{
+			_tcpClientMock = new Mock<ReconnectTcpClient>(HOST, PORT);
+			_networkStreamMock = new Mock<NetworkStreamWrapper>(null);
+
+			_tcpClientMock
+				.Setup(m => m.GetStream())
+				.Returns(_networkStreamMock.Object);
+
+			_networkStreamMock
+				.Setup(m => m.ReadAsync(It.IsAny<byte[]>(), It.IsAny<int>(), It.IsAny<int>(), It.IsAny<CancellationToken>()))
+				.Returns<byte[], int, int, CancellationToken>((buffer, offset, count, token) =>
+				{
+					var (delaySeconds, bufferResponse) = _readAsyncResponses.Dequeue();
+
+					return Task.Delay(TimeSpan.FromSeconds(delaySeconds), token).ContinueWith(t =>
+					{
+						Array.Copy(bufferResponse, 0, buffer, offset, bufferResponse.Length);
+						return bufferResponse.Length;
+					});
+				});
+
+			var client = new CallMonitorClient(HOST, PORT);
+			var tcpClientField = client.GetType().GetField("_tcpClient", BindingFlags.NonPublic | BindingFlags.Instance);
+
+			((IDisposable)tcpClientField.GetValue(client)).Dispose();
+			tcpClientField.SetValue(client, _tcpClientMock.Object);
+
+			var onConnectedMethodInfo = client.GetType().GetMethod("OnConnected", BindingFlags.NonPublic | BindingFlags.Instance);
+			_tcpClientMock.SetupGet(c => c.OnConnected).Returns((Func<ReconnectTcpClient, Task>)onConnectedMethodInfo.CreateDelegate(typeof(Func<ReconnectTcpClient, Task>), client));
+
+			_tcpClientMock.Object.OnConnected(_tcpClientMock.Object).Wait();
+			return client;
+		}
+	}
+}