This attribute indicates the active protocol state of the modem in
use.This attribute has one of the following values:
idle: Modem is in an inactive state and has no current connection
established.
training: Modem is attempting to establish a connection with the
far end modem via handshaking.
connected: Modem has establish a connection with the far end
modem.
releasing: Modem has begun tearing down the connection.