多项选择题
A.Multicasting B.Global addressing C.Forward-explicit congestion notification （FECN） D.Virtual circuit status messages. E.Backward-explicit congestion notification （BECN）
A.Loss should be no more than 1 percent. B.One-way latency should be no more than 150 ms C.Jitter should be no more than 30 ms D.Loss should be no more than 3 percent E.One-way latency should be no more than 150/2=75 ms F.Jitter should be no more than 300 ms
A.AF41 B.AF31 C.AF21 D.BE E.EF