Estimates of a communication system configuration, such as a DSL system, are based on operational data collected from a network element management system, protocol, users and/or the like. The operational data collected from the system can include performance-characterizing operational data that typically is available in an ADSL system via element-management-system protocols. Scanning, wherein a number of line profiles are used in connection with DSL loops having known configurations, can be used to generate a database or library of loop configuration information. One or more of the line profiles can be used with an unknown DSL loop to generate operational data from the unknown DSL loop that is compared to the loop configuration information in the database, allowing identification of loop configuration information pertaining to the unknown DSL loop. The unknown DSL loop operational data also can be used to determine whether one or more bad splices are present on the unknown DSL loop and, in some cases, the approximate or exact bad splice(s) location(s).