1
Summary
Computer networks use a tunneling protocol
when one network
protocol (the delivery protocol) encapsulates a different payload
protocol.
By using tunneling one can (for example) carry a payload over an
incompatible
delivery-network, or provide a secure path through an
untrusted network. Tunneling
typically contrasts with a layered protocol model such as those of OSI
or TCP/IP.
The tunnel protocol usually
(but not always) operates at a higher level in the model
than does the payload protocol, or at the same level. Protocol
encapsulation carried
out by conventional layered protocols, in accordance with the
OSI model or TCP/IP model
