Freed from the rigid provisioning required by SONET,carriers can dynamically allocate bandwidth using ATM virtual paths and virtual circuits on a temporary or permanent basis.

• 这样，电话公司就从SONET所要求的过死提供中解脱出来，能够在临时的或永久的基础上动态地分配使用ATM虚拟通路或虚拟电路的带宽。