A system and method for supporting multiple applications are described. A digital subscriber line system includes two transceivers in communication over a communication channel using multicarrier modulation. Application profiles are defined for characterizing transmission of information over the communication channel. Each application profile is a parameter set that is associated with a unique set of one or more applications that may become active between the transceivers and specifies the transmission requirements for such applications. Each transceiver stores the application profiles and transmits information over the communication channel according to the one of the stored application profiles. When a change in a number of applications active between the transceivers occurs, a second one of the application profiles is retrieved. The transceivers then transition to transmitting information over the communication channel according to the second application profile. The transitioning can occur without interrupting communication between the transceivers in order to retrain the transceivers. One of the transceivers transmits a message the other transceiver that specifies the second application profile and requests a transition to that second application profile. In one embodiment, the transceiver transmitting the request receives an inverted sync symbol from the other transceiver to synchronize use of the second application profile.