tunneling protocols - Definition from the Hotspot Shield Glossary
A tunneling protocol is used for the transferal of data over a network or the internet in a secure way. Tunneling protocols transport multiple standard protocols over a network and also allow for encryption of such connections as VPN networks.
Standard protocols usually split the data they intend to transport into two parts - The actual data, and instructions for how the data should be transmitted. Tunneling includes other data packets and protocols within the data it sends which in essence creates a “tunnel” between the two points for this other type of data to travel securely. Examples of tunneling protocols include SSH (Secure Socket), PPTP (Point to Point Tunneling Protocol) and IPsec.