[net.dcom] modems usable with call-waiting

guy@rlgvax.UUCP (Guy Harris) (01/10/85)

> Finally, it is desireable that the host treat loss of carrier
> as a disconnect and logoff request from the user.  Overriding
> this feature ... may leave a port logged in after a user has
> hung up without logging off.  Another user who
> dials in shortly thereafter will find him/herself already logged in
> as the previous user.  Definitely a security-hole.

Some systems treat a loss of carrier for greater than N seconds, for some
specified small N, as a disconnect and logoff request, but treat the
initial loss of carrier as a "freeze output" signal and treat a reappearance
of carrier within that N-second window as a "thaw output" signal.  This
way, a temporary line glitch leaves you logged in with a minimum of output
lost, but a permanent disconnection terminates the session.

	Guy Harris
	{seismo,ihnp4,allegra}!rlgvax!guy