lauren@rand-unix.ARPA (03/03/85)
Using call forwarding to try force incoming call bypass probably isn't a very good idea. I can think of at least three reasons: 1) If the forwarded call is answered, the company will be paying for the call (however short it may be) since most businesses pay for all local calls these days. Also, it seems rather wasteful to pay the extra money each month for call forwarding on every incoming modem line, even assuming it is available. 2) Various resets at the telco central offices could cause call forwarding to be cleared spontaneously at any time. It could take substantial work to always verify that call forwarding is still in effect. 3) Call forwarding normally results in a single short ring being applied to the primary destination phone as the forwarding takes place. This single ring could well be enough to trigger the incoming modem and cause possibly undesirable effects. The security problem with dial-back schemes is real, but like all security systems this method represents only an attempt at perfection, never actually reaching such a level. PBX systems with dedicated incoming and outgoing trunks can avoid the problems entirely. In virtually all cases, however, it would seem that dial-back systems are certainly superior (in terms of security) to straight-dial modems. Of course, they are usually also a much bigger pain to use for the authorized callers, and may not be needed in most situations. --Lauren--
lauren@rand-unix.ARPA (03/13/85)
By the way, there are some dial-back units that are specifically designed to use separate lines for incoming and outgoing calls, to prevent the "accidental" connection of an incoming call to an outgoing dialer (sometimes called "flare" in the trade). A unit called the "Defender II" is one such device. --Lauren--