encapsulation
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... Explicit Congestion
Notification bits [RFC4213]) from the encapsulated packets to the
tunnel path is out of scope.
...
... RFC3704]. The reason threat (2) exists is
that the IPv6 packet is encapsulated in IPv4 and hence may escape
IPv6 ...
... Transport mode is often also used in other
kinds of tunnels such as Generic Routing Encapsulation (GRE)
[RFC4023 ...
... Huttunen, A., Swander, B., Volpe, V., DiBurro, L., and M. Stenberg, "UDP Encapsulation of IPsec ESP Packets", RFC 3948prop, January 2005. ...
... Worster, T., Rekhter, Y., and E. Rosen, "Encapsulating MPLS in IP or Generic Routing Encapsulation (GRE)", RFC 4023prop, March 2005. ...