| 摘要 |
The Intelligent Multiservice Access System (IMAS) enables support for the next generation of virtual connections. Regardless of whether the communications lines coupled to the inputs and outputs of the IMAS are based on SVC, PVC, or a combination of PVC and SVC, the IMAS can support SVCs for a more flexible, timely, efficient, and manageable connection. In the more typical configuration, the loop side of the IMAS is PVC-based because the modems do not support SVC signaling, and the telecommunications backbone side is capable of supporting SVC signaling even though existing DSLAMs do not employ SVC signaling logic. With SVC support, the IMAS assists the ATM network in hand crafting an SVC-based connection almost immediately between end users when the originating end user wants to make a call to a destination end user, and tear down that virtual connection almost immediately when that call has completed. The SVC signaling is performed by a proxy signaling agent that resides in the IMAS to give the appearance to the ATM network in the telecommunications backbone that the loop side supports SVC signaling even though the line is PVC-based.
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