The type of physical devices that this user session
is attached to for the local end of the tunnel. The
meaning of each device type is explained below:
other: Any device that has not been
defined.
asyncInternalModem: Modem Pool device of an access
server.
async: A regular asynchronous serial
interface.
sync: A regular synchronous serial
interface.
bchan: An ISDN call.
xdsl: Future application with xDSL
devices.
cable: Future application with Cable
modem devices.