On Sun, 8 Oct 2000, Steven Kerr wrote:
> The +++ sequence used to send a Hayes compatible modem into command
> mode *must* be preceeded and followed by a finite time period of
> approximately 500mSec (1/2 Sec) on each side.
>
> ie: <TimePause>+++<TimePause>
>
> This is required so that the +++ can be part of a data stream without
> the modem dropping into command mode !
_ONLY_ if the modem manufacturer in question hasn't scimped on licensing
fees to Hayes.
The guard tone mechanism mentioned above requires an additional fee paid
to Hayes to get the rights to use it. Some modem manufacturers don't pay
this fee, and hence are not allowed to use chip/command sets which support
the guard tone.
Hence, some cheaper modems will accept the three pluses _without_ waiting
the guard tone time.
Hence tyhe success of the "ping of death" and other such processes.
DaZZa
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