Re: Active networking in ns

[Guillermo Rodriguez Garcia <guille@iies.es>]

At 11:38 14/10/99 +0100, 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.

Yes, this is the approach followed in the AN package for ns (in
www.tascnets.com/panama) which has been mentioned earlier
in this list.

>2) Write your agent so that rather than sending it to a given
>destination sends it only to a port on the next hop to the
>destination...

Yes, I could do this as well. This way I have to query
the routing tables to know which node is the next one in
the path from src to dst... how can I do this ?

Also, this approach has one disadvantage: it will be difficult
to simulate an hybrid network with both active and standard-IP
nodes, because I should send active packets to a port in the
next _active_ node, not just the next node; that is, if I had:

n1(src) ---- n2 ---- n3 ---- n4(dst)

and all the nodes were active except for n3, to send an active
packet from n1 to n4 I should do n1-n2-n4, skipping n3...
otherwise n3 would swallow the active packet because there
would be no active agent there to forward it to the next node.

I guess that the easiest way to do this actually involves having
a modified classifier, just like what PANAMA's AN pkg does.

Regards,
G.


--
Guillermo Rodriguez Garcia
<guille@iies.es>