Did you have a look at tcl/lib/ns-packet.tcl, and the packet header section in ns doc? - Haobo On Thu, 7 Jan 1999, Tao Yu wrote: > Hi, everyone, > > I am reading C++ code of ns and I am wondering > when and where the variables: off_cmn_, off_tcp_, off_ip_, ... > be initialized? Could anyone tell me the related file of the > initialization of these variables? > > Thanks, > Tao > > > >