Integrated Services (DiffServ) is a method for classifying traffic and providing quality of service for IP networks.
Compared to DiffServ, it allows for more detailed traffic flow management.
The basic principle for IntServ is that each application requiring service guarantees makes reservations from all implementing routers in the network.
IntServ uses RSVP messages within the network to reserve capacity. The reservations are described in a FlowSpec.