A.無(wú)國(guó)際統(tǒng)一的速率標(biāo)準(zhǔn) B.無(wú)國(guó)際統(tǒng)一的光接口標(biāo)準(zhǔn) C.上下電路成本高,結(jié)構(gòu)復(fù) D.網(wǎng)絡(luò)OAM能力強(qiáng)
A.GFP B.PPP C.LAPS D.ML-PPP