The Service Tree lists all services in "branched" groups, starting with the very general and moving to the very specific. Click on the name of any group name to see the sub-groups available within it. Click on a service code to see its details and the providers who offer that service.
Telephone Service Providers
Telephone companies called local exchange carriers (LECs) that provide ordinary voice-grade telephone service within a customer’s immediate geographic area. Services generally include connections to the local service provider and a variety of calling plans and features. Included are incumbent local exchange carriers (ILECs), the established "local telephone company" in a geographic region; and competitive local exchange carriers (CLECs), local telephone companies which compete with the incumbent for the local telephone business of customers. CLECs generally provide their own network and switching.