ATM Adaptation Layer Type 2: This AAL supports Class B traffic, which is connection-oriented, Variable Bit Rate (VBR), isochronous traffic requiring precise timing between source and sink.

• ATM适配层类型2：这种AAL类型支持B级传输业务，面向连接，可变比特率(VBR)，在传输源和目的地之间需要精确定时的同步传输。