08 July 2014

Printing the Routing Table in DSDV protocol

Printing the routing table for any protocol is quite a easier task if the data structure is known. You may read the post on "printing the routing table for AODV protocol" 

Now this post will let you know how to print the routing table when using DSDV protocol. As you know, the DSDV protocol is a table driven protocol in which each node maintains a Routing table for a given source to destination and the table gets updated periodically to maintain the routes.

But AODV protocol is a on demand routing protocol that deals with Route Request, Route Reply for forming the routes. So printing the routing table takes a minor tweak. But the DSDV protocol handles the routing table as a data structure, here is the steps to do it.

OS Used : Linux Mint 17 - 64 bit
NS2 Used : ns-2.35
Files to be modified: dsdv.cc and dsdv.h

Step 1:
The folder where ns2 installed on my machine /home/pradeepkumar/ns-allinone-2.35/ns-2.35
Execute these commands to access the DSDV protocol
$prompt] cd /home/pradeepkumar/ns-allinone-2.35/ns-2.35
$prompt] cd dsdv
$prompt] ls 
This commands will list you all the files in the folder ~dsdv/
Now open the files dsdv.cc and dsdv.h

Step 2: dsdv.h 
We will be printing the routing table in a file called dsdv.txt
include this line in the class DSDV_Agent{....
under protected mode as given below
.........
protected:
FILE *fp;
......

Step 3: dsdv.cc

input the following line inside the constructor DSDV_Agent() as shown below

DSDV_Agent::DSDV_Agent (): Agent (PT_MESSAGE), ll_queue (0), seqno_ (0),
  myaddr_ (0), subnet_ (0), node_ (0), port_dmux_(0),
  periodic_callback_ (0), be_random_ (1),
  use_mac_ (0), verbose_ (1), trace_wst_ (0), lasttup_ (-10),
  alpha_ (0.875),  wst0_ (6), perup_ (15),
  min_update_periods_ (3) // constants
 {

fp=fopen("dsdv.txt","w");

Step 4: dsdv.cc
There is a function called updateRoute(), include the red colored line given below in to the function as shown below.

void
DSDV_Agent::updateRoute(rtable_ent *old_rte, rtable_ent *new_rte)
{
  int negvalue = -1;
  assert(new_rte);

  Time now = Scheduler::instance().clock();

  char buf[1024];
  //  snprintf (buf, 1024, "%c %.5f _%d_ (%d,%d->%d,%d->%d,%d->%d,%lf)",
  snprintf (buf, 1024, "%c %.5f _%d_ (%d,%d->%d,%d->%d,%d->%d,%f)",
   (new_rte->metric != BIG
    && (!old_rte || old_rte->metric != BIG)) ? 'D' : 'U',
   now, myaddr_, new_rte->dst,
   old_rte ? old_rte->metric : negvalue, new_rte->metric,
   old_rte ? old_rte->seqnum : negvalue,  new_rte->seqnum,
   old_rte ? old_rte->hop : -1,  new_rte->hop,
   new_rte->advertise_ok_at);
fprintf (fp, "%c %.5f _%d_ (%d,%d->%d,%d->%d,%d->%d,%f)\n",
   (new_rte->metric != BIG 
    && (!old_rte || old_rte->metric != BIG)) ? 'D' : 'U', 
   now, myaddr_, new_rte->dst, 
   old_rte ? old_rte->metric : negvalue, new_rte->metric, 
   old_rte ? old_rte->seqnum : negvalue,  new_rte->seqnum,
   old_rte ? old_rte->hop : -1,  new_rte->hop, 
   new_rte->advertise_ok_at);

  table_->AddEntry (*new_rte);
fprintf(fp,"(%d),Route table updated..\n",myaddr_);
fprintf (fp,"VWST %.12lf frm %d to %d wst %.12lf nxthp %d [of %d]\n",now, myaddr_, new_rte->dst, new_rte->wst, new_rte->hop, new_rte->metric);

  if (trace_wst_)
    trace ("VWST %.12lf frm %d to %d wst %.12lf nxthp %d [of %d]",
  now, myaddr_, new_rte->dst, new_rte->wst, new_rte->hop,
  new_rte->metric);
  if (verbose_)
    trace ("VS%s", buf);
}

Step 4: compile and make
Execute the following steps one by one
$prompt] cd /home/pradeepkumar/ns-allinone-2.35/ns-2.35
$prompt] make
if there is no error, execute any tcl file that has the dsdv protocol as the routing protocol and run it  using ns filename.tcl
here is a sample output of the pradeep.txt file

D 0.03011 _0_ (1,-1->1,-1->4,-1->1,12.030111)
(0),Route table updated..
VWST 0.030110562161 frm 0 to 1 wst 6.000000000000 nxthp 1 [of 1]
D 12.95121 _0_ (1,1->1,4->6,1->1,23.451213)
(0),Route table updated..
VWST 12.951212565148 frm 0 to 1 wst 5.250000000000 nxthp 1 [of 1]
D 25.24463 _0_ (1,1->1,6->8,1->1,34.432132)
(0),Route table updated..
VWST 25.244631607088 frm 0 to 1 wst 4.593750000000 nxthp 1 [of 1]

Here is the screenshot of the simulation
DSDV Routing table
DSDV Routing table
If you are unsure how to do it, you may send your email address through the comment section or contact page to receive these files. 

T S Pradeep Kumar