can not connect to https site using CSOM

Hi guys

I'm working with CSOM to connect to SH site in 2010 outside the company, when I run the following code I receive a 403 forbidden error.

Is there any way to connect to https Sh sites? test in IE and run ok using windows Aut. without certificate

Do you have any idea?

System.Net.NetworkCredential credentials = new System.Net.NetworkCredential("xxxx", "xxx", "xx");
string siteUrl = "https://partner.coca-cola.com/sites/LARFC";
ClientContext clientContext = new ClientContext(siteUrl);
clientContext.AuthenticationMode = ClientAuthenticationMode.Default;
clientContext.Credentials = credentials;
Web site = clientContext.Web;
clientContext.Load(site);
clientContext.ExecuteQuery();
Console.WriteLine("Title: {0}", site.Title);

Ramiro B