Re: QueueMonitor in ns

[Christoph Haenle <chris@cs.vu.nl>]

Shuqian:

> Two questions, hope any ns-users will help to answer.
> 
> In QueueMonitor objects, what is the difference between the statitics collected 
> for variable, e.g. the parrivals_ & pktsInt_? I assume they all collect the 
> running sum of the # of packets received on a link.

parrivals_ measures the number of many packets that were enqueued in the 
(output) buffer corresponding to the link.

pktsInt_ integrates over time the buffer's queue size (in packets). So this 
var is related to, but not the same as parrivals_.

> Which state variable track the # of packets in transit on a link? parrivals_ or 
> pdepartures_?

pdepartures_ measures the packets ever sent over the link. Note that 
parrivals_ = pdrops_ + pdepartures_. I'm not aware of a proper means in ns-2 
to measure the number of packets currently being "on the wire".

Hope it helps,

    -Chris.