diff --git a/src/JSSoft.Communication.Client/JSSoft.Communication.Client.csproj b/src/JSSoft.Communication.Client/JSSoft.Communication.Client.csproj
index 299e87d..571b750 100644
--- a/src/JSSoft.Communication.Client/JSSoft.Communication.Client.csproj
+++ b/src/JSSoft.Communication.Client/JSSoft.Communication.Client.csproj
@@ -26,6 +26,7 @@ SOFTWARE. -->
     <DefineConstants>CLIENT</DefineConstants>
     <AssemblyName>client</AssemblyName>
     <PublishName>communication\client</PublishName>
+    <IsPackable>false</IsPackable>
   </PropertyGroup>
   <ItemGroup>
     <PackageReference Include="System.ComponentModel.Composition" Version="4.7.0" />
diff --git a/src/JSSoft.Communication.Server/JSSoft.Communication.Server.csproj b/src/JSSoft.Communication.Server/JSSoft.Communication.Server.csproj
index a520cc7..e612c23 100644
--- a/src/JSSoft.Communication.Server/JSSoft.Communication.Server.csproj
+++ b/src/JSSoft.Communication.Server/JSSoft.Communication.Server.csproj
@@ -21,11 +21,13 @@ LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 SOFTWARE. -->
 <Project Sdk="Microsoft.NET.Sdk">
+
   <PropertyGroup>
     <OutputType>Exe</OutputType>
     <DefineConstants>SERVER</DefineConstants>
     <AssemblyName>server</AssemblyName>
     <PublishName>communication\server</PublishName>
+    <IsPackable>false</IsPackable>
   </PropertyGroup>
   <ItemGroup>
     <PackageReference Include="System.ComponentModel.Composition" Version="4.7.0" />
@@ -41,4 +43,5 @@ SOFTWARE. -->
   </ItemGroup>
   <Import Project="..\Sharing\JSSoft.Communication.Services\JSSoft.Communication.Services.projitems" Label="Shared" />
   <Import Project="..\Sharing\JSSoft.Communication.ConsoleApp\JSSoft.Communication.ConsoleApp.projitems" Label="Shared" />
+
 </Project>
\ No newline at end of file
diff --git a/src/JSSoft.Communication/Compatibility/CancellationTokenSourceExtensions.cs b/src/JSSoft.Communication/Compatibility/CancellationTokenSourceExtensions.cs
new file mode 100644
index 0000000..19a8f60
--- /dev/null
+++ b/src/JSSoft.Communication/Compatibility/CancellationTokenSourceExtensions.cs
@@ -0,0 +1,23 @@
+// <copyright file="CancellationTokenSourceExtensions.cs" company="JSSoft">
+//   Copyright (c) 2024 Jeesu Choi. All Rights Reserved.
+//   Licensed under the MIT License. See LICENSE.md in the project root for license information.
+// </copyright>
+
+#if !NET8_0_OR_GREATER
+#pragma warning disable
+
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace JSSoft.Communication;
+
+internal static class CancellationTokenSourceExtensions
+{
+    public static Task CancelAsync(this CancellationTokenSource @this)
+    {
+        return Task.Run(() => @this.Cancel());
+    }
+
+}
+
+#endif // !NET8_0_OR_GREATER
diff --git a/src/JSSoft.Communication/Compatibility/CompilerFeatureRequiredAttribute.cs b/src/JSSoft.Communication/Compatibility/CompilerFeatureRequiredAttribute.cs
new file mode 100644
index 0000000..26eac4e
--- /dev/null
+++ b/src/JSSoft.Communication/Compatibility/CompilerFeatureRequiredAttribute.cs
@@ -0,0 +1,27 @@
+// <copyright file="CompilerFeatureRequiredAttribute.cs" company="JSSoft">
+//   Copyright (c) 2024 Jeesu Choi. All Rights Reserved.
+//   Licensed under the MIT License. See LICENSE.md in the project root for license information.
+// </copyright>
+
+#if !NET7_0_OR_GREATER
+#pragma warning disable
+// https://stackoverflow.com/questions/74447497/is-it-possible-to-use-the-c11-required-modifier-with-net-framework-4-8-and
+
+namespace System.Runtime.CompilerServices;
+
+[AttributeUsage(AttributeTargets.All, AllowMultiple = true, Inherited = false)]
+internal sealed class CompilerFeatureRequiredAttribute : Attribute
+{
+    public CompilerFeatureRequiredAttribute(string featureName)
+    {
+        FeatureName = featureName;
+    }
+
+    public string FeatureName { get; }
+    public bool IsOptional { get; init; }
+
+    public const string RefStructs = nameof(RefStructs);
+    public const string RequiredMembers = nameof(RequiredMembers);
+}
+
+#endif // !NET7_0_OR_GREATER
diff --git a/src/JSSoft.Communication/Compatibility/IsExternalInit.cs b/src/JSSoft.Communication/Compatibility/IsExternalInit.cs
new file mode 100644
index 0000000..7b44b3a
--- /dev/null
+++ b/src/JSSoft.Communication/Compatibility/IsExternalInit.cs
@@ -0,0 +1,15 @@
+// <copyright file="IsExternalInit.cs" company="JSSoft">
+//   Copyright (c) 2024 Jeesu Choi. All Rights Reserved.
+//   Licensed under the MIT License. See LICENSE.md in the project root for license information.
+// </copyright>
+
+#if !NET5_0_OR_GREATER
+#pragma warning disable
+using System.ComponentModel;
+
+namespace System.Runtime.CompilerServices;
+
+[EditorBrowsable(EditorBrowsableState.Never)]
+internal static class IsExternalInit { }
+
+#endif // !NET5_0_OR_GREATER
diff --git a/src/JSSoft.Communication/Compatibility/ObjectDisposedException.cs b/src/JSSoft.Communication/Compatibility/ObjectDisposedException.cs
new file mode 100644
index 0000000..85f9f5c
--- /dev/null
+++ b/src/JSSoft.Communication/Compatibility/ObjectDisposedException.cs
@@ -0,0 +1,22 @@
+// <copyright file="ObjectDisposedException.cs" company="JSSoft">
+//   Copyright (c) 2024 Jeesu Choi. All Rights Reserved.
+//   Licensed under the MIT License. See LICENSE.md in the project root for license information.
+// </copyright>
+
+#if !NET7_0_OR_GREATER
+#pragma warning disable
+namespace JSSoft.Communication;
+
+internal class ObjectDisposedException(string objectName)
+    : System.ObjectDisposedException(objectName)
+{
+    public static void ThrowIf(bool condition, object instance)
+    {
+        if (condition == true)
+        {
+            throw new System.ObjectDisposedException(instance.GetType().Name);
+        }
+    }
+}
+
+#endif // !NET7_0_OR_GREATER
diff --git a/src/JSSoft.Communication/Compatibility/RequiredMemberAttribute.cs b/src/JSSoft.Communication/Compatibility/RequiredMemberAttribute.cs
new file mode 100644
index 0000000..8818b1c
--- /dev/null
+++ b/src/JSSoft.Communication/Compatibility/RequiredMemberAttribute.cs
@@ -0,0 +1,17 @@
+// <copyright file="RequiredMemberAttribute.cs" company="JSSoft">
+//   Copyright (c) 2024 Jeesu Choi. All Rights Reserved.
+//   Licensed under the MIT License. See LICENSE.md in the project root for license information.
+// </copyright>
+
+#if !NET7_0_OR_GREATER
+#pragma warning disable
+#pragma warning disable MEN002 // Line is too long
+namespace System.Runtime.CompilerServices;
+
+[AttributeUsage(AttributeTargets.Class | AttributeTargets.Struct | AttributeTargets.Field
+                | AttributeTargets.Property, AllowMultiple = false, Inherited = false)]
+internal sealed class RequiredMemberAttribute : Attribute { }
+
+
+#pragma warning restore MEN002 // Line is too long
+#endif // !NET7_0_OR_GREATER
diff --git a/src/JSSoft.Communication/Compatibility/SetsRequiredMembersAttribute.cs b/src/JSSoft.Communication/Compatibility/SetsRequiredMembersAttribute.cs
new file mode 100644
index 0000000..8f320cf
--- /dev/null
+++ b/src/JSSoft.Communication/Compatibility/SetsRequiredMembersAttribute.cs
@@ -0,0 +1,13 @@
+// <copyright file="SetsRequiredMembersAttribute.cs" company="JSSoft">
+//   Copyright (c) 2024 Jeesu Choi. All Rights Reserved.
+//   Licensed under the MIT License. See LICENSE.md in the project root for license information.
+// </copyright>
+
+#if !NET7_0_OR_GREATER
+#pragma warning disable
+namespace System.Diagnostics.CodeAnalysis;
+
+[AttributeUsage(AttributeTargets.Constructor, AllowMultiple = false, Inherited = false)]
+internal sealed class SetsRequiredMembersAttribute : Attribute { }
+
+#endif // !NET7_0_OR_GREATER
diff --git a/src/JSSoft.Communication/UnreachableException.cs b/src/JSSoft.Communication/Compatibility/UnreachableException.cs
similarity index 79%
rename from src/JSSoft.Communication/UnreachableException.cs
rename to src/JSSoft.Communication/Compatibility/UnreachableException.cs
index 5cb2e30..5910d06 100644
--- a/src/JSSoft.Communication/UnreachableException.cs
+++ b/src/JSSoft.Communication/Compatibility/UnreachableException.cs
@@ -4,11 +4,12 @@
 // </copyright>
 
 #if !NET7_0_OR_GREATER
+#pragma warning disable
 using System;
 
 namespace JSSoft.Communication;
 
-class UnreachableException : SystemException
+internal sealed class UnreachableException : SystemException
 {
     public UnreachableException()
     {
@@ -19,4 +20,4 @@ public UnreachableException(string message)
     {
     }
 }
-#endif // !NET6_0_OR_GREATER
+#endif // !NET7_0_OR_GREATER
diff --git a/src/JSSoft.Communication/EndPointUtility.cs b/src/JSSoft.Communication/EndPointUtility.cs
index 6d5afe7..1ada7b3 100644
--- a/src/JSSoft.Communication/EndPointUtility.cs
+++ b/src/JSSoft.Communication/EndPointUtility.cs
@@ -82,6 +82,7 @@ public static bool TryParse(string text, [MaybeNullWhen(false)] out EndPoint end
         {
             return new($"{iPEndPoint.Address}", iPEndPoint.Port, credentials);
         }
+
         throw new NotSupportedException($"'{endPoint}' is not supported.");
     }
 #endif
diff --git a/src/JSSoft.Communication/Grpc/AdaptorServer.cs b/src/JSSoft.Communication/Grpc/AdaptorServer.cs
index ca0c0ed..2895b3e 100644
--- a/src/JSSoft.Communication/Grpc/AdaptorServer.cs
+++ b/src/JSSoft.Communication/Grpc/AdaptorServer.cs
@@ -34,7 +34,9 @@ internal sealed class AdaptorServer : IAdaptor
     private readonly Timer _timer;
 #if NETSTANDARD
     private Server? _server;
+#pragma warning disable S1450
     private AdaptorServerImpl? _adaptor;
+#pragma warning restore S1450
 #elif NET
     private IHost? _host;
 #endif
diff --git a/src/JSSoft.Communication/ServiceInstanceBuilder.cs b/src/JSSoft.Communication/ServiceInstanceBuilder.cs
index 571330e..8d4ee75 100644
--- a/src/JSSoft.Communication/ServiceInstanceBuilder.cs
+++ b/src/JSSoft.Communication/ServiceInstanceBuilder.cs
@@ -93,7 +93,11 @@ private static Type CreateType(
             }
         }
 
+#if NET7_0_OR_GREATER
         return typeBuilder.CreateType();
+#else
+        return typeBuilder.CreateType() ?? throw new InvalidOperationException("type is null.");
+#endif
     }
 
     private static void CreateInvoke(
diff --git a/test/JSSoft.Communication.Tests/JSSoft.Communication.Tests.csproj b/test/JSSoft.Communication.Tests/JSSoft.Communication.Tests.csproj
index a0eb54a..c657ac7 100644
--- a/test/JSSoft.Communication.Tests/JSSoft.Communication.Tests.csproj
+++ b/test/JSSoft.Communication.Tests/JSSoft.Communication.Tests.csproj
@@ -25,6 +25,7 @@ SOFTWARE. -->
     <ImplicitUsings>enable</ImplicitUsings>
     <IsPackable>false</IsPackable>
     <IsTestProject>true</IsTestProject>
+    <NoWarn Condition="'$(_IsPacking)'=='true'">$(NoWarn);NU1701</NoWarn>
   </PropertyGroup>
   <ItemGroup>
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.10.0" />