[ns] packets dropped by a router

[Simon Skaria <simon@digitalfountain.com>]

Hi,

I could not find a discussion on the following topic in the archive. So,

I
am posting this.

I have made a multicast simulation using ns-2.1b6 (Debian). When I
allocate
a packet and send to a group, the receiving group "free"s that packet. I

have some situations in my simulation, when the packets are received by
no
clients but they are just dropped by the router. This is indeed an
expected
behaviour in the special congestion control mechanism. Now my question
is,
what happens to those packets?

These packets should be ideally "free"d by the router before the router
dumps them. Otherwise, this leads to a memory wastage (as the number of
dropped packets increases, my available system memory drops down and the

program stops once it runs out of memory). I suspect that the router is
not
freeing the packets before it dumps.

* Could anyone please enlighten me about the behaviour of the router (in

NS)
in this scenario?

* What would I need to free the packets that are being dumped, if the
router
is not already freeing them?

* If the router does dump the packet, do you have any guess about the
reason
for the aforementioned program behaviour?

thank you very much in advance.

simon