Hello,
I would like to see DV routing dynamically alters routes between
deferent pairs of nodes. In my case, I would not like to
disable any links. I hope DV rouing can re-compute the routes between
each pair of nodes after I change the costs of links. It seems there is
no expected effect appearing. The original routes have been kept.
I have not understood well the DV routing implementation in ns-2.
What I confused are the instproc "Agent/rtProto/DV instproc compute
routes" and rtPeer, especially the latter one.
From the code, it seems, in each node, the number of rtPeers is
equal to the number of its neighbor nodes and, in each rtPeers, it
includes an array in which the route information to all the other nodes
from this neighbor nodes have been recorded. I really hope somebody can
explain a bit more about rtPeer. In addition, I am also puzzling some
variables such as $nextHopPeer. I do know what kind of information it
stores.
From the "Agent/rtProto/DV recv-update", it seems DV routing should
automatically compute new routes if the link cost is changed, because
...
set metricsChanged 0
foreach dest [array names metrics] {
set metric [expr $metrics($dest) + [$ifs_($nbr) cost?]]
if {$metric > $INFINITY} {
set metric $INFINITY
}
if {$metric != [$peer metric? $dest]} {
$peer metric $dest $metric
incr metricsChanged
}
}
if $metricsChanged {
$self compute-routes
incr rtsChanged_ $metricsChanged
$rtObject_ compute-routes
...
I really do not undstand the DV compute-routes well and hope
somebody can tell more about the programming idea of DV routing in ns
-2.
Thanks in advance!
Sun Kai