Encapsulated Security Protocol

Encapsulation is used for tunneling.

"Encapsulation" is the process of placing an entire data packet, including its headers, in the data payload of another packet. This encapsulated security protocol protects the encapsulated packet during transport over shared media like the Internet.

Function

The terms "encapsulation" and "tunneling" are interchangeable in networking technology. The concept is used either to smuggle packets of one protocol through an incompatible interface while carrying it in a packet designed for another protocol or to protect the packet from tampering. In the later case, the carried packet is entirely encrypted, rendering the routing information in the header unusable, necessitating the services of a carrying packet.

Application

The most common use of encapsulation is in the creation of Virtual Local Area Networks (VLANs). This configuration gives data carried over shared links, like the Internet, the same level of security offered by private Local Area Networks.

Examples

Two well known encapsulation protocols are the Generic Routing Encapsulation Protocol (GRE) and the Layer 2 Tunneling Protocol (L2TP). GRE contains its own encryption system; L2TP employs the IPSec (IP Security) protocol to provide encryption.

References

• Network Working Group: Generic Routing Encapsulation (GRE)