and, in most cases, sheer redundancy. Field serviceability, which means modular design and hot-pluggable cards or modules. An industry-standard design that is Network Equipment Building Standards (NEBS) compliant in terms of cards and chassis size, power consumption (maximum and typical), MTTF, etc. Of course, NEBS-type requirements apply to many types of service provider equipment, not just core boxes. In fact, the environmental requirements on access systems that sit in street cabinets are arguably even more stringent. The combination of these fundamental requirements and some obvious market dynamics create a new set of challenges for the market and an ensuing set of opportunities for network-processor man- ufacturers. For example, new packet classification requirements will appear with the widespread adop- tion of MPLS. Like windows capabilities originally reserved for fancy and expensive engineering workstations slowly but surely arrived on the humble PC when it became equipped with a powerful microprocessor and input/output (I/O) bus, functionality that was previously only available or ex- pected inside edge and/or core equipment will continue to expand its presence toward the access points, as the CPE devices increase their sophistication (due to application-driven demand) and speed. This increase will enable these devices to take advantage of 10 Gigabit Ethernet networks and to be deployed in the metropolitan areas. At the same time, a noticeable trend is that sophistication and service granularity migrate from lower-speed equipment to higher-speed equipment. This is possible because technology enables more work to be done in a given power/cost/space envelope and more work enables higher-value services to be delivered. DATA AND CONTROL PLANE PROCESSING We learned in Chapter 2 how a typical switching/routing system is structured architecturally in func- tional units that combine to compose two parallel processing paths. These are called the slow and fast processing paths, respectively. We also learned how t