Hyperactive Media Sales needs to provide a remote access solution for its traveling salespeople. They have a server running Windows Server 2012 R2 that can be configured as a remote access server for VPN connectivity. You have been reviewing the VPN protocols that are available and need to decide on the best protocol. The traveling salespeople often stay in hotels, so firewall compatibility is a serious concern. Which VPN protocol has the best compatibility with firewalls? Why?