wcf failed to add a service. service metadata may not be accessible - wcf

Question

i am new in wcf.i have simple wcf service for like calculator for add,substract,muliply,division etc. i have two endpoint in my service config file. one is basicHttpBinding and another one is netTcpBinding. when i am hitting f5 then wcf test client appear and showing the error wcf failed to add a service. service metadata may not be accessible but if i off the netTcpBinding and mex for netTcpBinding and hit f5 then wcf test client can invoke the service. here is my config entry. so please have a look and tell me why i am getting error for netTcpBinding and how to fix it.
<?xml version="1.0"?>
<!--Copyright (c) Microsoft Corporation. All Rights Reserved.-->
<configuration>
<system.serviceModel>
<services>
<service name="MyTcpActivation.CalculatorService" behaviorConfiguration="CalculatorServiceBehavior">
<endpoint address="" binding="netTcpBinding" bindingConfiguration="PortSharingBinding"
contract="MyTcpActivation.ICalculator"/>
<endpoint address="mex" binding="mexTcpBinding" contract="IMetadataExchange"/>
<endpoint address="" binding="basicHttpBinding" contract="MyTcpActivation.ICalculator" />
<endpoint address="mex" binding="mexHttpBinding" contract="IMetadataExchange"/>
</service>
</services>
<bindings>
<netTcpBinding>
<binding name="" portSharingEnabled="true">
<security mode="None"/>
</binding>
</netTcpBinding>
</bindings>
<!--For debugging purposes set the includeExceptionDetailInFaults attribute to true-->
<behaviors>
<serviceBehaviors>
<behavior name="CalculatorServiceBehavior">
<serviceMetadata httpGetEnabled="true"/>
<serviceDebug includeExceptionDetailInFaults="true"/>
</behavior>
</serviceBehaviors>
</behaviors>
</system.serviceModel>
<system.web>
<compilation debug="true"/></system.web></configuration>
please guide me where to fix in config file as a result there should no issue whatever binding i use. thanks

Answer 1

I think ... if you have two "IMetadataExchange" endpoints, then you need to provide different addresses. For example:
<service name="MyTcpActivation.CalculatorService" behaviorConfiguration="CalculatorServiceBehavior">
<endpoint address="" binding="netTcpBinding" bindingConfiguration="PortSharingBinding" contract="MyTcpActivation.ICalculator"/>
<endpoint address="mex1" binding="mexTcpBinding" contract="IMetadataExchange"/>
<endpoint address="" binding="basicHttpBinding" contract="MyTcpActivation.ICalculator" />
<endpoint address="mex2" binding="mexHttpBinding" contract="IMetadataExchange"/>
</service>