Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10 5/3/83; site hou4b.UUCP Path: utzoo!watmath!clyde!burl!ulysses!mhuxr!mhuxj!houxm!vax135!ariel!hou4b!dwl From: dwl@hou4b.UUCP (D Levenson) Newsgroups: net.dcom Subject: Re: modem info Message-ID: <1261@hou4b.UUCP> Date: Tue, 8-Jan-85 16:10:32 EST Article-I.D.: hou4b.1261 Posted: Tue Jan 8 16:10:32 1985 Date-Received: Wed, 9-Jan-85 05:24:33 EST References: <1362GMS@PSUVM> Organization: AT&T Information Systems Laboratories, Holmdel, NJ Lines: 21 Q: Is there a modem compatible with call-waiting? A: Many modems have an option (strapped, dip-switched, or software-configured) known as "disconnect on loss of carrier". This is usually enabled by the factory-supplied defaults. If you disable this option *at both ends* then the modem will not break the line connection when the carrier is interrupted by call-waiting. However, if the modem momentarily loses carrier, it may receive one or more garbage characters when a call-waiting tone is applied. Also, your host computer's operating system may force the modem to disconnect by dropping its DTR (data terminal ready) signal when it senses the modem's dropping carrier detect. Finally, it is desireable that the host treat loss of carrier as a disconnect and logoff request from the user. Overriding this feature, while providing some imunity to call-waiting, 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. -Dave Levenson AT&T-ISL, Holmdel