[ns] How can I get links used bandwith??

[Juha Villanen <jvillane@tct.hut.fi>]

Hi,

I'm just wondering that is it somehow possible to trace the used
bandwith on a link. I'm implementing a routing protocol(QOSPF) that
needs to know all the time the links available bandwith. So how should I
do it. When a new packet goes to the link, is it possible to log its
length and somehow the time, when the next packet will come to the
link???...Because if I know these parameters, then when a new packet
arrives to the link, I can calculate the bandwith used. My
treshold-based route-calculations then are triggered if a certain amount
change in bandwith occurs. If this kind of logging of bandwith everytime
when a new packet arrives to the link is possible, then is it too heavy
solution?? I mean, when there are a lot of packets arriving in a big
network, is this kind of solution too slow?....I'm not an expert in ns
so I dont know very well the implementation of links/queues! If there is
a queue installed, i suppose then this logging of bandwith have to be
done in a different way, because the packets are not given straight to
the link, but to the queue-object!??? So do I have to implement my
"bandwith monitor" to the queue-object or can I implement it for example
in transport agent??

I would be very pleased to have some help with this problem, please
advice,

Juha Villanen
Helsinki university of technology