As explained for bidirectional links in http://anrg.usc.edu/contiki/index.php/RPL_objective_function_%26_simulation_using_DGRM_model_in_cooja
I am using contiki 2.7 and I could not find Tools−−> DGRM configurator. Can anyone please help in steps on how to enable it.
The entry only shows up after creating a simulation model using DGRM. If this is not the case, you must give more information about which version of Cooja you are using.