> Obviously, "blind dialing", is > dialing in the absence of dial tone. Recalling > my modem days, some countries prohibited this > activity. Others allowed it, but may also > require you to recognize their dial tone when > you were not in blind dial mode. Why would it > be prohibited? A) Someone could already be > talking on that line you've seized (hence, no > tone); B) The exchange cannot place your call > (recognize your DTMF) until it is ready to do > so, ie has sent dial tone, you'd be tying up > a line on a call that can't go through. In some > countries, dial tone is not present for several > seconds*, without "wait for dial tone", or a > pause inserted in the string, most dial attempts > would be unsuccessful.
In any telephone exchanges I know off, taking the telephone off-hook, or otherwise terminating the line with a suitably low impedance, is known as a request for service. The exchange acknowledges that request for service by providing dialtone. That is all dialtone is, an indication that the central office is now prepared to accept address signals. If you dial before the CO is ready, you won't get the number you were trying to reach. That is a self correcting problem. Don't know why it should be prohibited. Ciao, Vic
