diff --git a/TGS.Server/CallLogger.cs b/TGS.Server/CallLogger.cs
new file mode 100644
index 0000000000..7ddb7e409d
--- /dev/null
+++ b/TGS.Server/CallLogger.cs
@@ -0,0 +1,61 @@
+using System;
+using System.Collections.Generic;
+using System.ServiceModel.Channels;
+using System.ServiceModel.Description;
+using System.ServiceModel.Dispatcher;
+
+namespace TGS.Server
+{
+	sealed class AddCallLoggerBehavior : IOperationBehavior
+	{
+		public void AddBindingParameters(OperationDescription operationDescription, BindingParameterCollection bindingParameters)
+		{
+		}
+
+		public void ApplyClientBehavior(OperationDescription operationDescription, ClientOperation clientOperation)
+		{
+			clientOperation.ClientParameterInspectors.Add(new CallLogger());
+		}
+
+		public void ApplyDispatchBehavior(OperationDescription operationDescription, DispatchOperation dispatchOperation)
+		{
+			dispatchOperation.ParameterInspectors.Add(new CallLogger());
+		}
+
+		public void Validate(OperationDescription operationDescription)
+		{
+		}
+	}
+	sealed class CallLogger : IParameterInspector
+	{
+		static readonly IDictionary<string, int> ActiveCalls = new Dictionary<string, int>();
+
+		public void AfterCall(string operationName, object[] outputs, object returnValue, object correlationState)
+		{
+			lock (ActiveCalls)
+				--ActiveCalls[operationName];
+		}
+
+		public object BeforeCall(string operationName, object[] inputs)
+		{
+			lock (ActiveCalls)
+			{
+				string res = String.Empty;
+				foreach (var I in ActiveCalls)
+				{
+					if (I.Value > 0)
+						res += Environment.NewLine + I.Key + ": " + I.Value;
+				}
+				if (res != String.Empty)
+				{
+					res = String.Format("Starting call {0}. Warning: other calls in progress!{1}", operationName, res);
+					Server.Logger.WriteInfo(res, EventID.CallTracking, 0);
+				}
+				if (!ActiveCalls.ContainsKey(operationName))
+					ActiveCalls.Add(operationName, 0);
+				++ActiveCalls[operationName];
+				return null;
+			}
+		}
+	}
+}
diff --git a/TGS.Server/EventID.cs b/TGS.Server/EventID.cs
index 9981fd199f..05043646ef 100644
--- a/TGS.Server/EventID.cs
+++ b/TGS.Server/EventID.cs
@@ -331,5 +331,9 @@ namespace TGS.Server
 		/// Warning: When a testmerge commit failed to be published
 		/// </summary>
 		ReferencePush = 7700,
+		/// <summary>
+		/// Info: When a call starts and another call hasn't completed
+		/// </summary>
+		CallTracking = 7800,
 	}
 }
diff --git a/TGS.Server/Server.cs b/TGS.Server/Server.cs
index eff1d58fa9..59f0abd5d4 100644
--- a/TGS.Server/Server.cs
+++ b/TGS.Server/Server.cs
@@ -4,6 +4,7 @@ using System.IO;
 using System.Reflection;
 using System.Security.Principal;
 using System.ServiceModel;
+using System.ServiceModel.Description;
 using TGS.Interface;
 using TGS.Interface.Components;
 using TGS.Server.Security;
@@ -342,7 +343,9 @@ namespace TGS.Server
 		void AddEndpoint(ServiceHost host, Type typetype)
 		{
 			var bindingName = typetype.Name;
-			host.AddServiceEndpoint(typetype, new NetNamedPipeBinding() { SendTimeout = new TimeSpan(0, 0, 30), MaxReceivedMessageSize = Definitions.TransferLimitLocal }, bindingName);
+			var endpint = host.AddServiceEndpoint(typetype, new NetNamedPipeBinding() { SendTimeout = new TimeSpan(0, 0, 30), MaxReceivedMessageSize = Definitions.TransferLimitLocal }, bindingName);
+			foreach (OperationDescription od in endpint.Contract.Operations)
+				od.OperationBehaviors.Add(new AddCallLoggerBehavior());
 			var httpsBinding = new BasicHttpsBinding()
 			{
 				SendTimeout = new TimeSpan(0, 0, 40),
diff --git a/TGS.Server/TGS.Server.csproj b/TGS.Server/TGS.Server.csproj
index 83f970c8c1..14e9e076e2 100644
--- a/TGS.Server/TGS.Server.csproj
+++ b/TGS.Server/TGS.Server.csproj
@@ -81,6 +81,7 @@
     <Reference Include="System.Web" />
   </ItemGroup>
   <ItemGroup>
+    <Compile Include="CallLogger.cs" />
     <Compile Include="Security\AuthenticationHeaderDecoder.cs" />
     <Compile Include="ChatCommands\ByondCommand.cs" />
     <Compile Include="ChatCommands\CommandInfo.cs" />