.net entity framework with oracle 11g

i'm using entity framework with the oracle provider (Oracle.ManagedDataAccessDTC)

Everything is working fine running that from visual studio, but when I publish that to IIS, I receive a connection error exception.

this is my webconfig witch is working just fine on visual studio:

<?xml version="1.0"?>
<configuration>

    <system.web>
        <compilation debug="true" targetFramework="4.0" />
    </system.web>
  <connectionStrings>
    <add name="Entities" connectionString="metadata=res://*/Model.Model.csdl|
         res://*/Model.Model.ssdl|
         res://*/Model.Model.msl;
         provider=Oracle.ManagedDataAccess.Client;
         provider connection string='DATA SOURCE=ORCL;PASSWORD=giovanni;USER ID=DB_ES'" providerName="System.Data.EntityClient" />
  </connectionStrings>
</configuration>

this is the error I get on IIS:

Server Error in '/EA' Application.

    ORA-12154: TNS:não foi possível resolver o identificador de conexão especificado

    Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. 

    Exception Details: OracleInternal.Network.NetworkException: ORA-12154 could not resolve the connect identifier specified

    Source Error: 


    Line 24:         public List<CADASTRO> GetCadastroBy(string CPF, string Cartao)
    Line 25:         {
    Line 26:             return ent.CADASTRO.Where(x => x.CPF.Equals(CPF) && x.NUMEROSEUCARTAO.Equals(Cartao)).Select(x => x).ToList<CADASTRO>();
    Line 27:         }

Queries from sql plus works fine.

any ideas guys?

SOLUTION:

  <oracle.manageddataaccess.client>
    <version number="4.121.1.0">
      <settings>
        <setting name="TNS_ADMIN" value="C:\app\giovanni.saraiva\product\11.2.0\dbhome_2\network\admin"/>
      </settings>
    </version>
  </oracle.manageddataaccess.client>

on webconfig.