RE: TO COMPRESS OR NOT TO CMPRS (please reply)

[Rob Adams <[e-mail]>]

I concur with Derrell.   Whether compression is a good thing remains to be seen.
However, if we are going to do compression we should determine the appropriate
way to implement it.   I don't think this issue has been thought through enough 
byall of us  to flatly say that IPsec is the right vehicle for delivering compression.

I'm not against compression, I'm against doing it more than once and at all sorts of
layers throughout a stack.   We already have compression at the hardware link layer.
We have compression of certain data by applications such as voice/video/image etc.
TLS may end up with compression of its own.   Now we're contemplating adding 
compression at a low enough level that the application won't have any control over
what gets compressed.  And the layer we're thinking of is low enough that we won't
be able to use stateful compression algorithms because we're adding compression
to a stateless protocol.  

We're also talking about linking compression with a specific set of IPsec transforms.
This seems limiting and binding to me.  Everytime we have a new set of transforms
we'll have to go through this discussion again.  "Where are we going to stick the 
bit or byte this time that indicates this packet...... "   Wouldn't a framework for 
including compression in all transforms make more sense if we are to link compression
to IPsec at all?  

TCP seems to be a much better place to do compression than at the IP layer 
for many reasons.