Re: where to add marker for packets (for diff-serv)

[Urs Thuermann <thuerman@ibr.cs.tu-bs.de>]

thuerman@ibr.cs.tu-bs.de (Urs Thuermann) writes:

>    I think of writing a Tcl proc that creates a new node, creates and
>    instance of the marker, sets the target_ of the marker to the
>    node's entry{} and then sets the node's entry{} to point to the
>    marker.  Any thoughts on this?

Since in contrast to the ns documnetation a node has no entry_
instance variable, I tried to insert my packet marker in place of the
node's classifier:

	set n [$ns node]
	set m [new Marker]
	$m target [$n set classifier_]
	$n set classifier_ $m

This does't work however since then the node will later try to install
into the classifier's slot using the classifier_ instance variable
which now points to my packet marker.

Is there another way to insert the packet marker between the node's
entry point and the classifer?

Or do I have to define a special subclass of Node that will allow
this?


BTW, the packet marker is defined like

	class Marker : public Connector { ... };

	void Maker::recv(Packet *p, Handler *h) {
		/* determine flow aggregate for this packet,
		   measure average bandwidth and compare to porfile
		   then mark packet accordingly.
		*/
		...

		send(p,h);
	}

Like you might guess from this, I want to simulate diff-serv
mechanisms.  If someone has code to share or other suggestions I'd
really appreciate your answers.


TIA

urs