Tunneling is a method that protects the contents of protocol packets by encapsulating them in packets of a different protocol. Actually, transferring a letter to your grandma includes the use of a tunneling process. You create the personal letter (the primary content protocol packet) and place it in a container (the tunneling protocol). The container is delivered through the postal service (the untrusted intermediary network) to its proposed receiver.
Tunneling can be used in many conditions, such as when you are avoiding firewalls, gateways, proxies, or other traffic control devices. The bypass is accomplished by encapsulating the restricted content inside packets that are authorized for sending. The tunneling process stops the traffic control devices from blocking or filtering the communication because such devices don’t know what the packets really contain.
Tunneling secures the contents of the internal protocol and traffic packets by covering it in an authorized protocol used by the intermediary network or connection. Tunneling can be applied if the original protocol is not routable and to have the entire number of protocols supported on the network to a minimum.