sorry for being late in responding to this subject...
please
refer to the below easy link.
> You might want to take a look
at
> draft-park-scalable-multi-natpt--00.txt that
> proposes to do
precisely that.
http://www.ietf.org/internet-drafts/draft-park-scalable-multi-natpt-00.txt
Daniel
(Soohong Daniel Park)
Mobile Platform Laboratory, SAMSUNG Electronics