Which two statements correctly identify considerations to take into account when deciding on Campus QoS Design elements?（）

• A、Voice needs to be assigned to the hardware priority queue.
• B、Voice needs to be assigned to the software priority queue.
• C、Call signaling must have guaranteed bandwidth service.
• D、Strict-priority queuing should be limited to 50 percent of the capacity of the link.
• E、At least 33 percent of the link bandwidth should be reserved for default best-effort class.