Typical edge switches combine ASSPs such as framers, HDLC controllers, and SAR devices, with general-purpose CPUs . While the CPU software provides some application flexibility, separate line cards are typically required for each interface type.
Density is limited by processing performance, PCI bandwidth, and component board space.
A generous best-case design might support up to five DS3s. System cost is driven by the ASSP costs, with complex HDLC controllers and OC-12 SARs typically costing hundreds of dollars for each part. Channel Processors are dedicated to ATM, SAR, HDLC multiplexing and demultiplexing, Frame Relay, and IP functions, enabling wire-speed operations. System costs are dramatically reduced, both through integration of multiple, expensive components and provision of much higher port densities. OEM customers leveraging the Smart Networks platform.