Automatic detection of the virtual circuit setting and encapsulation type of a DSL line. A DSL modem determines the correct virtual path identifier (VPI) and virtual channel identifier (VCI) by sending OAM loopback requests to different VPI/VCI pairs until a valid loopback reply is received. PPPoA encapsulation...http://www.google.com/patents/US20040052263?utm_source=gb-gplus-sharePatent US20040052263 - Method and apparatus for automatically detecting virtual circuit settings and encapsulation types in a DSL network
