arrier understands that in nearly all instances, the provisioning time interval is allocable 90 percent to the access facility side of the network and 10 percent to the backbone side. A provisioner could wait days, weeks, or even months for a fiber to be brought into a building from the street, through a riser, or onto a floor, and for power to be installed to run a carrier's NE (such as an edge device, an ADM, and so on). Once the network is in place, you can typically change bandwidth parame- ters in a matter of a few minutes or hours, even when utilizing traditional technologies. Although disposing quickly of the misconception that any near-term technology will alleviate provisioning time for optical services in the 4.6 million commercial buildings in the United States that do not have fiber links, you may subscribe to the assertion that all-optical networking requires optical (wavelength) switching, and ION requires wavelength switches that are dynamically reconfigurable (again, the switching may only be automated in the core). Notable recent efforts include MPLS and MPXS, which is now known as GMPLS. The introduction of WDM technology represents a step toward the deployment of all-optical networks. Optical add/drop modules (OADMs) Chapter 7 (also called optical add/drop nodes) and optical crossconnects (OXCs) are the additional steps taken. The migration would be completed by the addi- tion of cost-effective and reliable optical switching. OXCs facilitate optical networking in an OTN environment in the sense that lightpaths can be set up end to end (see Table 7-1). However, most lightpaths still have to be pro- visioned manually. ION proponents argue that optical switches and appro- priate signaling protocols could automate this process. However, signaled services have historically failed to see deployment. X.25 supported both pro- visioned (PVC) and signaled (SVC) connections; only the PVC service has seen widespread deployment. Frame Relay supports both provisioned (PVC) and signaled (SVC) connections; onl