[ns] Connection between DiffServ domains

["Tuan Nguyen Ngoc" <tuan.nguyen@hevs.ch>]

Hello all,

I am quite new in DiffServ in NS2. As far as I know, we can define several DiffServ domains in the same network topology, is it right ? 
If it is right, here is my problem:
I looked at the NS2's DiffServ examples but all of them defined only one DiffServ domain. So, my question is: Do we connect 2 edge routers of 2 DiffServ domains together ?How can I connect 2 (or several) DiffServ domains together ? It means that which kind of links (one duplex or  2 simplex), queue management strategy, DS code point, ... 

It would be very nice if somebody can send me one example about this ?

Thank you very much in advance,
Tuan