[ns] how to insert a classifier into a node

[Hei Xiaojun <heixj@eea119.ee.ust.hk>]

Dear Ns users

In the chapter of "node and packet forwording", the manual mentions the
node interface should "allow individual routing modules that implement
their own classifier to insert their classifiers into the nod".  I have
checked ~/tcl/ex. There are two scripts fq.tcl and fq-cbr.tcl, which
involves inserting a classifier. If I want to insert multiple classifiers,
I still cannot figure out how to  do this. Are there any example scripts
for the study? Or please drop me some lines of hints.

thanks a lot

yours
sean