Path: utzoo!telecom-request Date: 20 May 91 17:44:17 GMT From: "Fred R. Goldstein" Newsgroups: comp.dcom.telecom Subject: Re: A Very Simple ISDN Question Message-ID: Organization: Digital Equipment Corp., Littleton MA USA Sender: Telecom@eecs.nwu.edu Approved: Telecom@eecs.nwu.edu X-Submissions-To: telecom@eecs.nwu.edu X-Administrivia-To: telecom-request@eecs.nwu.edu X-Telecom-Digest: Volume 11, Issue 381, Message 6 of 10 Lines: 43 In article , ivgate!Kim.Fosbe@uunet.uu. net (Kim Fosbe) writes... > Will ISDN make our modems obsolete? Is it true that all we will have > to do is plug in an RS232 cable from the PC port to the phone and dial > up any system like we do now? Is there a way to use your plug-in > modems when you have ISDN at home? Has anybody ever thought of that? > Also, is there a way to use your answering machine when you get ISDN? If both ends of the call are on ISDN, then modems are obsolete: ISDN gives you 64 kbps dial up. You'll still need an ISDN Terminal Adapter (TA) to convert RS232 to ISDN, though; it's like a modem but a tad bit faster. Of course if you have ISDN at only one end, it had better have a modem if it wants to communicate with an analog line! That's possible too ... Some ISDN networks may also provide a modem pool service. The answering machine question, though, brings up another nit about ISDN: For the average residence, ISDN makes no sense for _voice_. You'd need a new ISDN answering machine, and I've not seen one yet, and it wouldn't be cheap. Better to have a TA to adapt analog lines and devices (phones, answering machines) to ISDN, using a different TA to handle the high-speed data. Note that only one phone can be on a call at a time using ISDN digital phones, so an analog phone will work better! (It needs a TA, which generically means any devices that adapts non-ISDN devices to run over ISDN, phone or data.) > Another question while I am on the subject. Are these black AT&T > digital phones that are replacing the hold-button phones in offices > actually ISDN phones? One guy tells me they are and another guy tells > me no. Both of them are electronic people. Full of questions, aren't I? AT&T 7500-series sets are ISDN. The 7400-series sets aren't. ISDN sets are generally found behind Centrex, while the non-ISDN sets (cheaper) are typically found behind PBXs. They look similar. Fred R. Goldstein Digital Equipment Corp., Littleton MA goldstein@delni.enet.dec.com voice: +1 508 952 3274 Do you think anyone else on the planet would share my opinions, let alone a multi-billion dollar corporation?