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Re: threats ID
Masataka, you conclude by saying
However, TCP is not IP, which is the point of my presentation
We can hardly disagree. But TCP is not SCTP, UDP, DCCP or ICMP either.
That's why TCP is not IP.
The systems level argument for a layer 3.5 solution
There is no such thing as layer 3.5.
Network layer solutions are at layer 3, transport layer solutions are
at layer 4. PERIOD.
is that it can cover
all cases, including ones we have not invented yet.
UDP, which we already invented, can not be covered by network
You are correct that a layer 3.5 solution requires cached state, probably
Anything with wrongly guessed timeout is no solution.
There is a classical
solution to that, which is for the ULP to send a keepalive signal to prevent
the cache from timing out.
That is a modification to the ULP, including application ones and
That you must modify something above layer 4 gives a very convincing
evidence, even for those who don't understand layering enough to dream
of layer 3.5, that layer 3.5 is a fallacy.
That would indeed be a ULP enhancement, but a very
minor one and not essential.
That is a well known argument for NAT.
However, it is not an enhancement but a restriction.
It is the essential reason why NAT is not acceptable.