problems in implementing a diffserv queue

[Lakshminarayanan <lsubrama@lrc.epfl.ch>]

hi,
    i  implemented an ansolute priority queue which i called Diffserv
over ns.
the compilation of the file was proper and the object file Diffserv.o
was
produced.

    Then when the command c__ -o ns/  *.o  in the make file was
executed,
i got the following error message which i do not understand.

   the error message says
....../ns-allinone//ns-allinone-2.1b5/ns-2.1b5/diffserv.cc:43: undefined
reference to
'Diffserv Virtual  Table'
*** Error code 1
make:Fatal error: command failed for target 'ns'

can anyone help me fix this bug.

thank you
lakme.