[ns] A two-way policy

[Giovanni Neglia <giovanni.neglia@tti.unipa.it>]

I would like to implement a policy for TCP flows, which monitors not
only the data flow but also the ack flow (the policer should estimate
the TCP window through the difference of the sequence numbers).
My question is the following:
can a policy intercept acks? It seems that the policy is associated to
the queue, and so it can't receive acks because they come in another queue.
I could insert another policy on the ack queue to monitor them, but how
can the first policy access a variable of another policy?

Thanks in advance for your attention,
Giovanni Neglia