http://www.rfc-editor.org/rfc/rfc5346.txt
RFC 5346: Operational Requirements for ENUM-Based Softswitch Use, J. Lim, W. Kim, C. Park, L. Conroy2008-10-01T23:00:00-00:00These experiences show that an interim solution can maintain the stability of ongoing commercial softswitch system operations during the initial stage of ENUM service, where the DNS does not have sufficient data for the majority of calls. This memo provides information for the Internet community.