Sporadic connectivity issues with exchange server when traveling

Has anyone experienced sporadic connectivity to the exchange server when traveling? (Traveling domestic and internationally. It seems to happen more over seas then it does domestic.) We use Outlook 2013 and the settings are correct. Yes, I have talked to Microsoft to help troubleshoot, and they have no clue. It's not consistent. I thought it might be a port setting that the hotel/business is using? If so, there's no way to troubleshoot it because we use the exchange server. There's plenty of "what to do" if you are using a POP email account, but not exchange. Any insight or advice would be very welcomed.