ed recent advances in optical components and software architectures to develop next- generation SONET. (See Figure 4-1 for a view of the evolution.)³ For exam- ple, advances in transceivers, SONET Application-Specific Integrated Circuits (ASICs), PoS, forward error correction (FEC), digital wrappers, Transitioning to Data-Optimized Optical Networks Figure 4-1 Factors related to the Data/IP-Optimized transition to next- Service Management generation platforms. Dynamic Architecture Extend Mesh to Edge Tiered Protection, SLAs Introduce Mesh in Core Fast Provisioning Reduce Footprint Lower Cap/OpEx Capacity Mgmt. (DCS/ADM) Voice Static Architecture Protected Services Chapter 4 lumped and distributed amplification, gain and dispersion equalization, optical switching, high-speed ASICs for electronic switching and grooming, and Vertical Cavity Surface-Emitting Lasers (VCSELs) were leveraged to reoptimize SONET equipment. We also saw a gradual transition from SONET rings to intelligent mesh architectures, although it was more often applicable to the long-haul and regional area network than to the metro- politan network. Current networks' multiple layers can be difficult and costly to provision and manage. Therefore, a much simpler SONET-based approach is advan- tageous. Solutions include Optical Ethernet, namely the various virtual local area network (VLAN)/campus-extended LAN technology approach RPR-based systems Streamlined PoS GFP-based PoS Multiservice solutions afforded by next-generation SONET (or by any platform for that matter) must incorporate QoS, fault tolerance, and the restoration and low latency of SONET. Additionally, it must be able to han- dle the bursty nature of (some) data networks while offering the scalability and capacity to transport video applications. It is also desirable for these capabilities to be added incrementally because each service provider's tim- ing and business model may be different. Figure 4-2 is a usage example of next-generation SONET, with the implication that metro access may b