uced: switches with electrical cores (i.e., first-generation optical switches) and switches with optical cores (i.e., next-generation optical switches). The electronics in first-generation switches slow their capability to work with the very high rates that the fiber itself can support. The future lies in the pure optical switches, but we still have to fully develop the microphotonics industry; thus, integrated photonic circuits (discussed later in this chapter) are really the next key technology required to drive the optical networking industry forward. Optical switches fall into two main categories. First, the multiservice provi- sioning platform (MSPP) enables carriers to get a quick start on offering a full range of services. It resides either in the carrier's point of presence (POP) or at the Chapter 11 Optical Networking customer site, and it incorporates DWDM and offers customers different grades of IP service, telephony, and other offerings. (MSPPs are discussed in detail later this chapter.) Second, big switches can be deployed at the carrier's local exchange. These switches act as on-ramps, funneling large volumes of traffic from IP, ATM, and MPLS backbones on and off the optical core. Challenges in Deploying Optical Switches Because we are in the early stages with optical switches, we have to deal with issues such as how to quickly provision services, how to accommodate billing, and how to elegantly separate services. In the next three to five years, we should start seeing these more sophisticated elements become available in pure optical form. As mentioned earlier, with end-to-end optical networking, because transmis- sion rates are reaching the Tbps, Pbps, and even the Ebps levels, the bottleneck is moving to the network elements. The faster the light pulses are emitted-that is, the faster the data rates on the line get-the more technically challenging it is to handle optical-electrical-optical conversions at line speed. Therefore, to fully take advantage of the capacity being created by WDM, fiber n