RE: [ns] Packet Caching

[aashishp <aashishp@usc.edu>]

HEllo,

HEre is the code. I don't have the complete code in the place i currently
am in. I am sending you the key lines.

void cache_packet(Packet *p)
{
	Packet *pack = p->copy();
	... obtain the seq no of packet

	cache.insert(make_pair(seqno,pack));
	/*
		cache is a map class of the form
		map<int,Packet *>
	*/
	my_ll->sendUp(p);
	//here the original packet is sent up the link
	//layer
	//If i don't store the copy of the packet in the map class, the
	//packet is successfully up the stack
	//however, moment i store the copy in the map class,
	//the original packet is not sent. I don't know what happens to
	//it. I cannot explain the behavior. If i don't store it anywhere
	// the whole purpose of caching is defeated


}

If u know of any other structure that can store the packets successfully,
kindly let me know.

Thanks

Aashish Patil


On Tue, 27 Nov 2001, Neundorf Alexander wrote:

>
>
> --
> Free Dmitry Sklyarov !
> http://www.freesklyarov.org
>
> > -----Original Message-----
> > From:	aashishp [SMTP:aashishp@usc.edu]
> > Sent:	Tuesday, November 27, 2001 4:17 AM
> > To:	ns-users@ISI.EDU
> > Subject:	[ns] Packet Caching
> >
> > Hello,
> >
> > I am trying to cache packets in intermediate nodes at the link layer.
> > However, I am having problems storing the packets in some structure.
> > Basically,
> >
> > I create a new copy using the Packet::copy() method.
> > I was storing these copies in a stl map class. However, moment I store
> > this copy, the original packet from which I made this copy is not
> > forwarded using the sendUp(Packet *) method of the link layer.If i don't
> > store then the packet is forwarded. Why should the copy affect the
> > behavior of the original packet?
> >
> > I tried to use an array of Packet* statically allocated. This is giving me
> > segmentation faults. Will dynamically creating an array affect the
> > way
> > Packet class is handled in ns.
> >
> > i.e. if I do
> > Packet *list = new Packet[num]
> >
> > I ask this because packets are already allocated and kept in ns. I will be
> > allocating more by this call
> >
> > Thanks
> >
> > Aashish Patil
> >
> >
> 	Please send some more of your code, otherwise we can't help.
>
> 	Bye
> 	Alex
>