 OC-48 (the equivalent of 55 DS3s) to a customer premise for a cost to the carrier of about $50,000 per month (in order for the carrier to be able to recover costs). Using CWDM, this service can be pro- vided for about $20,000 per month, or less. An important difference between metro core and long-haul systems is making DWDM an option on the system, not a requirement. Cards that support DWDM will significantly increase the cost of the system (because each channel requires its own com- ponents), yet there are situations where DWDM is not required. Such a sit- uation would arise when a service provider has to pull new fiber to a location, but, for a period of time, would only need to provision one wave- length. Here, single-wavelength SONET would suffice, and CWDM or DWDM could be added later as bandwidth requirements expanded. Fig- ure 5-32 identifies the opportunity space for these types of metro products. Dense Wavelength Division Multiplexing (DWDM) Systems The Opportunity Space Figure 5-32 Opportunity space for price-optimized edge devices. MAEPADs SONET Next-generation Web-Hosting ASP Firm The product set includes the following: Edge Packet Aggregation Devices (EPADs) (see Figures 5-33 through 5-37) CO Massively Arrayed EPADs (MAEPADs) of various footprints (see Figure 5-38) Specifically, the developer plans to manufacture a family of edge prod- ucts, ranging in price from $2,500 to $40,000, which support a variety of access, network, and routing protocols; as well as CO products, ranging in port count from 32 to 128, which also support various speeds, protocols, and media.¹9 The product space for the EPADs is shown in Table 5-5, which shows each product optimized to a class of carrier applications and a cost- benefit pencil. The protocol model of the modular EPAD is shown in Figure 5-39. Point A depicts a routing or bridging function (when null). Point B depicts the net- work-side data link layer (DLL) technology. The maximum-form EPAD product is shown in Figure 5-40; however, different subproducts are devel