 Long Haul Ethernet Ethernet Switch Routers Ethernet Optical Switch Switch EVOLVING ELEC/VLAN MODEL (HIGH END) DUAL ENTRY-STREAMLINED Customer Building Metro Access Metro Core Ethernet Switch Optical Crossconnect Long Haul Services: Ethernet Ethernet Switch Routers Ethernet Switch high-speed connections (at 622 Mbps or higher). In this scenario, IP runs directly over SONET, which in turn runs on the OTN. MPLS has been added to the architecture to provide for connection-oriented services. IP over SONET to IP over ION In the next stage of the evolution, SONET could theoretically also be removed (although the SONET Advances and Opportunities in Next-Generation SONET Figure 1-11 EVOLVING NEXT-GENERATION CARRIER MODEL A Architecture SINGLE ENTRY evolutions: next- Customer Building Metro Access Metro Core generation carriers in packet mode Optical Ethernet Switch Switch (subset). Copper/ Optical Switch Fiber Optical Crossconnect Services: Ethernet Long Haul Ethernet Switch Routers Ethernet Optical Switch Switch EVOLVING NEXT-GENERATION CARRIER MODEL A DUAL ENTRY Customer Building Metro Access Metro Core Ethernet Optical Optical Switch Switch Switch Optical Crossconnect Services: Long Haul Ethernet Ethernet Switch Routers Ethernet Optical Switch Switch EVOLVING NEXT-GENERATION CARRIER MODEL A DUAL ENTRY - STREAMLINED Customer Building Metro Access Metro Core Ethernet Switch Optical Crossconnect Services: Ethernet Long Haul Optical Ethernet Switch Switch Routers Ethernet Switch framing is generally thought of as being retained), and IP could run directly over the OTN. In this scenario, the IP control plane could interact directly with the control plane of the OTN (an OTN with a dynamic control plane is often referred to as the ION) for dynamic establishment of optical connections. The eventual commercial outcome of this stage remains to be established, particularly with Chapter 1 Figure 1-12 EVOLVING NEXT-GENERATION CARRIER MODEL B Architecture SINGLE ENTRY evolutions: next- Customer Building Metro Access Metro Core gene