Re: [ns] Info about Classifier Architecture (fwd)

[Andrea Josi <mr_josi@yahoo.it>]

Hi,

this instead is what happens when DV routing is used:

on every node, a rtObject (the manager of the
different routing agents that are mounted on the node)
is installed;  at the very beginning, rtObject has no
reachability information: 
in its constructor (the "init" method),
all the destinations are marked as unreachable

set metric_($dest) [$class set unreach_]

and the classifier's slots for those destinations have
a NullAgent as a target

$node add-route [$dest id] $nullAgent_ 


When eventually an update is received, these methods
are invoked:

rtProtoDV::compute-routes  (route-proto.tcl)
rtObject::compute-routes   (  //           ) 
node::add-routes           (ns-node.tcl)
node::add-route            (  //       )

Cheers,

            Andrea.



 --- "V.R.Sundar" <vsundar@usc.edu> ha scritto: > 
> Hi,
> 
> On Thu, 5 Jul 2001, Sunil Gowda wrote:
> 
> > Hi,
> >     Can anyone please let me know when and how the
> "slot_" array in the
> > address classifier is initialized?
> 
> Here is what i understand so far ( somebody correct
> me if i am wrong). the
> slot_ array is indexed by the dest addr and points
> to the object this
> classifier should hand the packet to for the given
> dest address. To do
> this the method install is called which in turn
> allocs slot_ if needed. To
> give an idea of how it works ( with static routing
> and flat-heirarchy):
> 
> (1) simulator::run(tcl code) calls..
> (2) routelogic::configure(tcl) calls..
> (3) agent/rtproto/static::init-all (tcl)
> (4) simulator::compute-routes(tcl)
> (5) simulator::compute-flat-routes(tcl) which does:
> (5-a) routelogic::compute ( this i think is C code )
> - maps to
> compute-routes in c code.Finds the next hop for all
> dests.
> (5-b) simulator::populate-flat-.. (c code i think,
> again without the
> cmd.).For each dest uses the nexthop previously
> found to find the link to
> use and then calls
> (6) node::add_route which calls
> (7) routingmodule::add_route for every routing
> module installed in the
> linked list each of which installs the
> dst/link-object in its own
> classifier.
> 
> there is a chapter in the manual on classifiers
> which gives an idea of how
> classifiers work. 
> 
> sundar
> 
> -- 
> V.R.Sundar
> Ph: 323-734-1920
> 
>  

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