EC switches to ILEC loops, that capacity was hard to tap into. Competition did, however, at least nominally expand, primarily via UNE Platform. By 2000, CLECs had software that could tap into ILEC opera- tional support systems and place UNE-P orders. In the majority of cases, this switching of carriers was only a change in records. The customer's phone number was unchanged, and the same loop remained on the same switch port. Software vendors even built applications that could take a subscriber's number and convert it to UNE-P with the click of a mouse. A large number of CLECs thus sprung up whose business model was to be a pure play in UNE-P, with marketing and billing but no network of their own. And the big IXCs adopted this model in spades: MCI's pioneering nationwide-local-calling plan, The Neighborhood, was built out of UNE-P. Neither MCI nor AT&T-both of whom had extensive local switching networks for business customers-provided residential service on their own local networks in the early 2000s; UNE-P's mar- gins were higher. In December 1999, CLECs nominally controlled about 8 million lines, 4.3% of the country's local telephone lines [10]. Of these, about half were provi- sioned via resale, and under a third (about 2.7 million lines) were on CLEC- owned transmission facilities. That latter category included ISP dial-in circuits delivered locally in CLEC collocations. About 6% of CLEC lines-around half a million-were on the newly minted UNE Platform. About a million lines used UNE-loop; that included the DLECs as well as classical-model voice providers. One year later, after the last full year of the boom, CLEC-owned facilities had almost doubled, to 5.2 million lines. UNE-Loop had more than doubled, to CLECs' Winning Strategies Are Met by Rule Changes about 2.4 million lines, but that paled compared with UNE-P, which more than quintupled in size to over 2.8 million lines. Resale lines were being converted to UNE-P in droves; by mid-2001, UNE-P had more lines than resale. By December 2003, CLECs had a nomi