[ns] How to add a new or modify existing protocols in NS2.32

[Bringo Shawn]

Hi there,
If we add/modify a protocol and implement it in NS-2.32, what changes we need 
to do in NS-2.32 ?
Also when we add object files in /ns-2.32/Makefile, inside OBJ_CC, does we need 
to compile .cc files of the protocol by 'gcc' command or just running the 
'touch /common/packet.cc and 'make' commands would be enough?

Please guide.

Regards