Re: threats ID

[Masataka Ohta <mohta@necom830.hpcl.titech.ac.jp>]

Tim Shepard;

>>There is no such thing as layer 3.5.

> As far as I am aware, the IETF has never reached a consensus on how
> the layers are to be numbered or what layers should exist.

Thank you for agreeing with me that layer 3.5 is an improper
terminology.

However,

> Note that IPSEC adds a layer, increasing the number of layers below
> TCP by one.

it is clearly stated in RFC2401 "Security Architecture for the
Internet Protocol", which defines IPSEC architecture, that:

   The goal of the architecture is to provide various security
   services for traffic at the IP layer, in both the IPv4 and IPv6
   environments.

It should also be noted that that Brian said layer 3.5 means he
thought IP layer layer 3 and transport layer layer 4, on which
I have no objection.

						Masataka Ohta