A method and apparatus for selectively terminating sealing current in an
asymmetric digital subscriber line modem is provided. The technique
comprises providing a mechanism (e.g., a resistor or suitable current
sink) to a DSL modem (e.g. an ADSL modem or any XDSL modem used where
POTS is underlying service). The mechanism is operable to be dynamically
switched on and off and to operate under low current conditions. The
system allows for provision of DSL (e.g., ADSL or XDSL where POTS is the
underlying current) in the absence of plain old telephone service (POTS)
and for improved performance.