a DSL modem is delivered to the customer. The ISP also orders traffic backhaul services from the NSP to connect from the DSLAM, co-located in the ILEC's end office, to the ISP's rack in the NSP's switching office. Here we can see how the ISP creates a DSL and Internet access service from a specialized supply chain. The ISP uses its own routers and servers, the NSP's Internet access and backhaul services, the DSL wholesaler's DSLAM, customer premises equipment, and through its relationship with the ILEC, the ILEC's local loop. Figure 7 provides a physical overview of the various components and providers that make up the customer's DSL service. The Ultimate Guide to Building and Delivering OSS/BSS NSP Switching ILEC End Office Center NSP's Co-Location Cage NSP Cross Connect Backhaul Circuit and Switch ISP Rack Modem Customer Premises DSLAM DSL Wholesaler's Co-Location Cage/Space Internet Figure 7. DSL Service Architecture 4.1 Digging Deeper Behind all of the interactions we discussed SO far is a complex series of communications and work tasks distributed among the various parties. The Internet underlies almost all of the IIC-to-IIC and customer-to-IIC communications that must occur, thus supporting the supply chain and the eOSS environment we will discuss. This OSS environment, in our example, will involve tight integration among the IICs' OSS platforms, specifically among the workflow managers. We will assume the customer uses a Web-based customer interface to order its DSL service from the ISP. The Web-based interface provides several functions. First, it prompts the customer for the address in order to compare it against a loop information database. A loop information database stores data Chapter 3 - Automating the Internet Infrastructure Supply Chain about the condition and capacity of the local loops serving businesses and residences in the ISP's region. This information is used to let the customer know his capacity options - in other words, the speed of the DSL connection. When the customer selects a capacity