问题：

[多选] Which two statements about the DiffServ QoS model are true？（）

A . DiffServ requires RSVP to set up a path through the network to accommodate the requested QoS.
B . Network traffic is identified by class， and the level of service is chosen for each class.
C . The DiffServ model relies on a fairly simple mechanism to provide QoS over a wide range of equipment.
D . RSVP enables the DiffServ model to provide end-to-end QoS.
E . The DiffServ model is more scalable than the IntServ model.
F . The flow-based approach of the DiffServ model is ideal for large scalable implementations such as the public Internet.