[Ns-developers] DelayBox - ns-3

[Mathieu Lacage]

On Mon, 2008-04-07 at 16:24 +0000, Tom Henderson wrote:
> >-----Original Message-----
> >From: Mathieu Lacage [mailto:mathieu.lacage at sophia.inria.fr]
> >Sent: Monday, April 7, 2008 07:58 AM
> >To: 'Matt Crinklaw'
> >Cc: 'ns-developers'
> >Subject: Re: [Ns-developers] DelayBox - ns-3
> >
> >
> >On Sat, 2008-04-05 at 16:17 -0400, Matt Crinklaw wrote:
> >
> >> DelayBox doesn't actually do the packet classification.  Packets are
> >> given a flow id by the TCP Agent (this is the ns-2 equivalent of
> >> ns-3's TCP Socket) which generated them.
> >
> >Ok. Thanks for the precision.
> >
> >> Flow ids (in my mind) are something that should be assigned on a per
> >> connection basis.  Since this is the case, it seems that the most
> >> logical thing to do would be to add functionality to the TCP Socket
> >> code.  This added functionality would allow the code using the socket
> >> to assign a flowid to that socket.  The socket would then assign its
> >> flowid to each packet that it generates.
> >
> >I think that it would be nice to avoid adding cruft to the socket code
> >and to leave this to the application generating traffic or to move this
> >in some more generic packet classification facility.
> 
> I recommend looking at netfilter conntrack facility for Linux.  We
> talked earlier about adding support for common netfilter hooks in the
> kernel.  Some kind of stateful conntracking object might be
> (optionally) aggregated to such a hook.
> 
> A quick and dirty option would be to add an optional packet tagger to
> ns3::Socket.  It could be enabled similar to how Packet metadata is
> enabled.  That might be appropriate to make progress on DelayBox
> without getting distracted immediately by building a general
> conntrack/netfilter facility.

It certainly would be nice to have such a generic facility but my point
(badly made, I know) was that there are already a set of hooks which
provide sufficient functionality for this specific task: the trace
hooks.

regards,
Mathieu