Re: [ns] Buffer monitoring on wireless

[Richa Jain <richaj@ee.iitb.ac.in>]

> Hi ns-users,
> on wired networks it's easy to monitor a buffer size with a queue-monitor
> object, but I have problem with this on wireless networks. Here, we have the
> ifqlen. How can I monitor it? It's possible indipendently from the trace file?


Do I understand your problem correctly : you want to access the IFQ - and
keep track of it's length. right?

As far as I know, you'll have to dig into the C++ code a bit to do that.
Cant get it directly from the trace files. Depending from which level you
want to access the IFQ - just by itself, or from the LL or MAC, you'd have
to put in code apropriately.

the IFQ code is basicaly in the files prique.cc and queue.cc. The
packetqueue has a function len(), that you can use to access the length.
Just geta pointer to the que, and access it's length from soemwhere in
your c++ code.

For my code, I required a pointer to the queue (again, like u, i needed
the IFQ length) at the MAC. Got it indirectly thru the LL. The LL is the
only layer in the (ns) wireless stack that has a pointer to the IFQ
(albeit in nsb7a, it hasnt been set).
If you really want to get the IFQ length in your trace files - maybe you
could do something similar - get a poinetr to the IFQ at the MAC, and
print the IFQ length along with the mac-trace. FAr out solution, but it'll
work.


Hope this helps.


-richa