[ns] packet encapsulation

[Kaleelazhicathu R R Kumar <iscp9133@nus.edu.sg>]

hi,
   if i encapsulate an existing ip packet with an ip header as in ip
tunneling at the sending gateway..can i retrieve the initial ip header
information at the receiving gateway after removing the encapsulated header
in NS???do i need to preserve the initial header information before i
encapsulate it??? 
   regards.
   Renjish.