Layered bandwidth management in ATM/SDH (SONET) networks

A layered bandwidth management system for transporting both STM and ATM traffic from customer circuit elements over a transport network, and for accommodating increasing ATM traffic demand over time, said bandwidth management system comprising:

• first ATM transport means for transporting STM traffic having embedded ATM cells mapped to STM traffic payloads over first physical channels, said physical channels having a fixed bandwidth allocation;
• hybrid transport means for separately transporting STM and ATM traffic over separate first physical channels;
• second ATM transport means for transporting ATM cells over second physical channels;
• first bandwidth control means responsive to said STM traffic contained in said first physical channels for directing STM traffic in fixed bandwidth allocations;
• and,
• second bandwidth control means responsive to ATM traffic contained in said separate first physical channels for switching said ATM traffic, said second bandwidth control means capable of directing ATM traffic to said first physical channels for more efficient physical channel bandwidth utilization.