Справочник по конфигурациям в C# — 19.1. Структура

<System.serviceModel>
  <services>
    <service name="MyService" behaviorConfiguration="MyBehavior">
      <endpoint address="" 
                binding="basicHttpBinding"
                contract="IMyService" />
    </service>
  </services>

  <bindings>
    <basicHttpBinding>
      <binding name="MyBinding" maxReceivedMessageSize="2147483647">
        <readerQuotas maxDepth="32" />
      </binding>
    </basicHttpBinding>
  </bindings>

  <behaviors>
    <serviceBehaviors>
      <behavior name="MyBehavior">
        <serviceMetadata httpGetEnabled="true" />
        <serviceDebug includeExceptionDetailInFaults="true" />
      </behavior>
    </serviceBehaviors>
  </behaviors>

  <client>
    <endpoint address="http://..."
              binding="wsHttpBinding"
              contract="IMyService"
              name="RemoteService" />
  </client>
</System.serviceModel>