Re: [ns] Hello messages

[guzinu]

hello mechanism isn't active by default. because of the following
sentences in aodv.cc file.

#ifndef AODV_LINK_LAYER_DETECTION
   htimer.handle((Event*) 0);
   ntimer.handle((Event*) 0);
#endif

Guzin ULUTAS (CEng)


 Hi,
 Sombody can tell me if hello messages mechanism is active in
 default AODV(I'm using ns-2.29) and how can I monitor it in trace files?

 Thanks in advance,

 G



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Re: [ns] Creating an AODV agent

[guzinu]

No, line is already included in your script, no need to do anything else.

 Hi
 Is it necessary to create an AODV agent and attach it to every node if the
 following line is already included in the script?
 set val(rp)AODV;# routing protocol

Re: [ns] How to use cmu-trace

[guzinu]

   you can learn it from the trace file after completion of your
simulation. you can search the field whose value is RTR and node ID is
what you want with some shell programming experiment.

   
 Hi all,
I my project i want to trace/count the no of pkts etc. I am working
 with wireless ad hoc network simulation.=0A   In that i couldn't
 understand how to use the following instruction...
set T [cmu-trace Send RTR $node]
 from this how i am going to know the RTR pkts sent by the node?
  Pl. help. I am trying very hard but couldn't understand.
 Regards

 Vijay

Re: [ns] How can I add extension to packets in AODV?

[guzinu]

you can change AODV packet header (RREQUEST,RREPLY,RERROR) with yours. Or
you can add some extra fields in this packet headers. All the headers
using by the AODV are defined in the aodv_packet.h file. For example in
the following code, temp field is added by me.

 Guzin ULUTAS (CEng)
struct hdr_aodv_request {
 u_int8_trq_type;// Packet Type
 u_int8_treserved[2];
 u_int8_trq_hop_count;   // Hop Count
 u_int32_t   rq_bcast_id;// Broadcast ID
 nsaddr_trq_dst; // Destination IP Address
 u_int32_t   rq_dst_seqno;   // Destination Sequence Number
 nsaddr_trq_src; // Source IP Address
 u_int32_t   rq_src_seqno;   // Source Sequence Number
 double  rq_timestamp;   // when REQUEST sent;
 u_int_32_t  temp;
 inline int size() {
   int sz = 0;
   sz = 8*sizeof(u_int32_t);
   return sz;
  }
};


 Hi

 I am using ns-allinone-2.29. I need to add an extesion to pakets  in AODV:
 when I open AODV directory, I found some files lik aodv.h , .cc and .o,
 where can I do the chang in this routing protocol.
 and after that how can i run it.
 if ther ein anyone know the answer ..please reply me.

 Thanks
 Mohamed

Re: [ns] What does AGT in trace file indicate?

[guzinu]

it indicates agent level. For example the trace file that is the output of
a wireless scenario using AODV routing protocol. The agent level
represents the layer that implements AODV routing protocol.


 Hello all...

 Just I woulk like to ask what does the AGT in the output trace file
 indicate? or where is in the OSI model (i.e. in which layer)?

 Thanks in advance

 Yazeed




 Yazeed Ahamd Al-Sbou
 Sheffield Hallam University
 Sheiffield, UK

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Re: [ns] Interval for HELLO message

[guzinu]

Hi Choong,
You did what I am thinking. But I don't understand why the results are
the same with your former experiments. I think about this topic, and I
can find anything else, I inform you.
 What do you mean with round ? you can explain more clear, maybe I
can help.

  Best Regards and have a good day.


Guzin Ulutas (CEng)

Re: [ns] AODV - Route Repair Issue

[guzinu]

  Hi Gabriel,

  I send you some explanations about local repair from rfc 3561.
localrepairtimer function that is called from rt_ll_failed function is
for local repair as explained below.

/*_*/
6.12. Local Repair

   When a link break in an active route occurs, the node upstream of that
break MAY choose to repair the link locally if the destination was no
farther than MAX_REPAIR_TTL hops away.  To repair the link break, the
node increments the sequence number for the destination and then
broadcasts a RREQ for that destination.  .

/*_*/

from rt_ll_failed function
/* if the broken link is closer to the dest than source, attempt a local
repair. Otherwise, bring down the route. */

  if (ch-num_forwards()  rt-rt_hops) {
 local_rt_repair(rt, p); // local repair
  return;
  }
  else
   {
drop(p, DROP_RTR_MAC_CALLBACK);
while((p = ifqueue-filter(broken_nbr))) {
drop(p, DROP_RTR_MAC_CALLBACK);
 }
 // below function sends error message to the neighbors
 nb_delete(broken_nbr);
}

As you see above, if local repair is processed, local_rt_repair
function is called. And this function implements 6.12 section of the
rfc. Else all the packets waiting in the queue are dropped, and
senderror function is called from nb_delete function as Cenker says
before in the list.

 Best Regards.

Guzin Ulutas (CEng)

Re: [ns] How to use both otcl and C++?????

[guzinu]

 Hi Asma,
 You must write your own command function in your c++ code.For
Example, your class name is MyAgent and then it must contain a member
function called by command . Via this function, you can call
functions that are defined in your class (MyAgent). This function
provides you control power over the c++ functions from your otcl
code.

int MyAgent::command (int argc, const char*const* argv) {
if (argc==2) {
  if(strcmp(argv[1],private-function)==0) {
   private-function();
   return (TCL_OK);
   }
 }
}

Above code demonstrates how you can call private-function, that is
defined in your c++ code, from your otcl script.
http://nile.wpi.edu/NS; contains a good document about this topic.

Have a good day.

Guzin Ulutas (CEng)

[ns] Does DSDV stores the Routing table of its neighbours?????

[guzinu]

 Hi Jeevesh,
 DSDV stores the Routing table for each node that is modified by the
information received by the node's neighbor nodes. rtable.h file
contains class RoutingTable and rtable.cc stores each entry, contains
information about the current node's neighbors, into rtable_ent *rtab
member variable of RoutingTable class.
In dsdv.cc, makeupdate function builds a packet which contains
information about the current node's neighbors. if updatetype=1, all of
the records hold by the rtab member will be send, else appropriate
records will be send.
I hope, this answer helps you.


Guzin ULUTAS (Computer Engineer)

Re: [ns] Does DSDV stores the Routing table of its neighbours?????

[guzinu]

   Hi Jeevesh,
   Actually DSDV doesn't have the all the neighbours's routing table with
it, at the time of calculation of shortest path. it has got only
necessary information gathered by the neighbor nodes during triggered
and periodic update.
It gets the routing update packet from its neighbors, and compare this
packet with its routing table. Necessary updates will be implemented.
But not all the table stored by this node.

Guzin Ulutas (CEng)