Re: Active networking in ns

[Tarik Alj <aljtarik@ozias.inrs-telecom.uquebec.ca>]

> X-Authentication-Warning: mash.CS.Berkeley.EDU: majrdomo set sender to 
owner-ns-users@irtf.CS.Berkeley.EDU using -f
> X-Sender: guille@mailhost.iies.es
> Date: Fri, 15 Oct 1999 21:10:42 +0200
> To: ns-users@mash.cs.berkeley.edu
> From: Guillermo Rodriguez Garcia <guille@iies.es>
> Subject: Re: Active networking in ns
> Mime-Version: 1.0
> 
> At 14:07 14/10/99 -0400, you wrote:
> 
> >> [active networking in ns]
> >> >
> >> >I am playing with similar problems, I have found two ways of doing this:
> >> >
> >> >1) Modify the classifer/forwarder in the node to check for an active
> >> >packet mark.  This then gives it to the AN processor for the current
> >> >node.
> >
> >Without modifying a classifier it could be possible to have a filter
> object that 
> >would do the checking and send the packet to AN processor if necessary.
> Place 
> >the filter between the classifier and the node so that every packet received 
> >could be checked.
> 
> This is also similar to what the PANAMA's AN package does: they
> have a classifier-switch which then is connected to the 'standard'
> classifier and to one classifier-an (for active packets). Standard,
> regular packets are forwarded to the 'standard' classifier while
> active packets are forwarded to the classifier-an object.
> 
> But this approach also involves modifiying classifier.cc, so that
> the first object found in the node is classifier-switch instead
> of classifier.

You could install the classifier-switch in the adress's classifier slots. I 
don't think it implies modifying ns internals very much. Basically you are 
inserting an object, that implies modifying the targets a bit (putting the 
filter in the classifier's slots and stting the filter's target to be the link's 
head).

>From what i have understood of what you wich to implement, i would have put the 
filter in between the node and the classifier, so that packets that need 
processing can be send to the processor and the other packets send to the 
classifier wich puts them on the link. 

I don't know what is to happen to packets out of the AN processor but i guess 
you could send them to the classifier so they can be put on the link.

> 
> Is this what you suggested - or am I missing something ? Can I
> put the 'filter object' you mention above between the node and
> the classifier without modifying ns internals ?
> 
> Regards,
> G.
> 
> --
> Guillermo Rodriguez Garcia
> <guille@iies.es>

Tarik