customer's facilities to the network provide retail access service to customers. The access service layer originates or terminates the communications of individual cus- tomers. Generally, customers are located on the periphery of the network. Provision of wholesale access places demands on the transmission, sortation, and distribution facilities of the network. The configuration of the network will be altered as the network expands the carrying capacity of these facilities or adds new transmission lines, switches, and distribution facilities to serve competing carriers. These changes are likely to require alteration of the configuration of the network. If the parties obtaining wholesale access serve different customers, there will be changes in distribution facilities. If the pattern of traffic changes due to changes in distribution services, this will create the need for changes at both the sortation and transmission levels. 3. Interconnection Access Like wholesale access, interconnection access has an ambiguous impact on the total demand for network capacity. The addition of customers residing on other networks can induce the customers on the primary network to increase network usage. The increase in traffic can require additional capacity. At the same time, interconnection access can cause demand for network capacity to decrease. Under wholesale access, all of the customers still reside on the primary network. In other words, all of the functions associated with the three service layers described above are still performed by a single network. Although there may be some substitution in Economic Effects of Regulating Access to Networks terms of which carrier fulfills the merchant activities, the transmission, sortation, and distribution functions are still performed by the primary network. Interconnection access, in contrast, clearly envisions that some customers will reside on other networks. This means that some of the transmission, sortation, and distribution functions will be satisfied by capacity provided b