Cathy,
DiffServ does not try to control e2e qos by a explicit way which is adopted by InterServ. It just tries to identify several service level and relize that by orchestrating routers' behavior accross the network. The basic idea is: if every router delivers packet with the same policy the edge-to-edge QoS is predicable.
> how can we do the admission control without concerning it's route?
Incoming packet is classified according to SLA.
>how can the resource be reserved in the interior router?
it does not reserve any resource for special flow but share resource between service class.
hope this helps.
Does someone know this kind of work ?Thanks!Cathy