多项选择题 Which two B-RAS service offerings maintain the analog dial-up model with centralized user authentication，authorization，andaccounting？（）

单项选择题 You would like to configure an ATM PVC with a virtual circuit identifier of 33 on virtual path 0.The PVC should use an unspecified bit rate and be encapsulated in the AAL5SNAP format.Which command accomplishes this goal？（）

单项选择题 What is the maximum attainable bandwidth using an analog data modem？（）