[ns] How to access mac layer in c++ of ns2

[Daniel Dekst]

Hi,
   
  I have never done anything with TCP layer, so I'm not sure.
  But a general rule I summarized is that
   
  1) If the two layers you want to cross-access are adjacent, you can use uptarget_/downtarget_
   
  2) If they are not, it is a bit of difficult to make the pointer clear. My method is to use tcl to get the pointer. You must have seen the usage of TclObject::lookup() many times.
  My case is to let my SensorAgent to access Mac802_11, thus
  in my sensor-agent.cc  (can be others such as aodv.cc)
  implement a command
if (strcmp(argv[1], "access-mac") == 0) {
                        mac_pt_ = (Mac802_11*)TclObject::lookup(argv[2]);
                        if (mac_pt_ == 0)
                                return TCL_ERROR;
                        return TCL_OK;
}
  here mac_pt_ is defined in sensor-agent.h
  Mac802_11  *mac_pt_
  you may also need to declare Mac802_11 as friend class.
  Once you execute the following command in your tcl file, mac_pt_ gets the right pointer and you can use it now.
  $sensoragent_($i) access-mac [$node_($i) set mac_(0)]
   
  vice versa
  set mac_ [$node_($i) set mac_(0)]
  $mac_  access-agent [$node_($i) agent 255]
  you implement "access-agent" command in mac layer
   
  so the point is that you need to know how to get TCP
  set tcp_  ???
   
  Best,
  Pei

Basim Javed <basimjaved at gmail.com> wrote£º
    I just read, and you are correct.
Could u plz also tell me how to access the TCP layer from the node pointers in C++, and how does we know that this is the current node (some thing like self)? So I want each node to access the TCP and PHY layers from within itself, and also the reverse of it: i.e. within TCP I want to access the MAC functions of the concerned node, if possible?

thanks many.
basim






Pei Huang, Ph.D. student
Dept. of Computer Science and Engineering
Michigan State University
http://dekst.awardspace.com
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