A terminal adapter unit for use in a wide-band network based on an ISDN is connected in the data path between a data terminal and the ISDN, and functions to control accessing and releasing a line through the ISDN to an opposite data terminal, in accordance with whether or not data are actually being...http://www.google.de/patents/US5278822?utm_source=gb-gplus-sharePatent US5278822 - Communication control method for ISDN, and data terminal adaptor apparatus for same
