Is there a proc named "getlink"?

[K Sun <ksun@essex.ac.uk>]

Hello,
     I am sorry for my question.
I am just trying RSVP/ns.
However, I met an error.

...
ns: _o162 get-adc 1 2: _o3: unable to dispatch method getlink
    while executing
"[Simulator instance] getlink $n1 $n2"
    (procedure "_o162" line 2)
    (Agent/RSVP get-adc line 2)
    invoked from within
"_o162 get-adc 1 2"
...

   I have checked the code of RSVP/ns and I did not find the definition 
of a proc named "getlink".  What I want to know is whether the 
Simulator Class has an instproc named "getlink" in the ns-2.1b5 itself?

     Regards,

         Sun Kai