[ns] node_ base Agent class

[andersn@telecom.lth.se (Anders Nilsson)]

Hi everyone!

I am fairly new to the C++/OTcl linkage part of ns and I am trying to get a full 
grip on part VII in the turorial (A new protoco for ns). Here are two things 
that I don't fully get.

Agent/Ping instproc recv {from rtt} {
          $self instvar node_
          puts "node [$node_ id] received ping answer from \
                $from with round-trip-time $rtt ms."
  }
  
Where does the instance variable node_ come from? In the tutorial it says that 
it is a member variable of the base class for Agent. I can't find a reference to 
it in any of the code. I have checked many source files, including Agent.cc and 
Agent.c. Do anyone have any ideas?

Here is another part that troubles me:

sprintf(out, "%s recv %d %3.1f", name(), 
              hdrip->src_.addr_ >> Address::instance().NodeShift_[1],
              (Scheduler::instance().clock()-hdr->send_time) * 1000);
              
What is the method name()? It clearly should be a metod which executes the recv 
proc mentioned above. But how does it operate?
Also, what is the Address::instance stuff doing? Some sort conversion from 
internal node source address to an tcl address?

I would really appreciate your help,

/Anders