Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!wuarchive!texbell!vector!telecom-gateway From: westmark!dave@uunet.uu.net (Dave Levenson) Newsgroups: comp.dcom.telecom Subject: Re: Caller ID Device Message-ID: Date: 11 Nov 89 00:37:02 GMT Sender: news@vector.Dallas.TX.US Organization: Westmark, Inc., Warren, NJ, USA Lines: 31 Approved: telecom-request@vector.dallas.tx.us X-Submissions-To: telecom@eecs.nwu.edu X-Administrivia-To: telecom-request@vector.dallas.tx.us X-TELECOM-Digest: volume 9, issue 503, message 2 of 4 In article , mjw06513@uxa.cso.uiuc. edu (Mary J Winters) writes: > My questions are these: Are the plans for this device still available? > If I do manage to build one, will the device work for caller ID in all > areas, or do different telcos use different schemes for transmitting > the information? Caller*ID is part of the Class(sm) feature package. It is implented in the same way throughout the Bell System. The information is delivered using a simplex 1200 bps fsk data transmission (similar to the modulation used on 202-type modems) which occurs after the first ring on lines subscribed to the service. Colonial Data Technologies (the folks who made the Call Identifier(tm) box I use with this service) is rumored to be working on a PC card capable of receiving this data transmission and passing it to some software they'll supply. I don't know how open the application interface will be. In the "Bell System of the Future" a new kind of calling number delivery will be offered to ISDN subscribers. This is a different transmission method, and is digital, rather than analog. Instead of a modem, you'd need an ISDN processor, capable of implementing a sizeable subset of HDLC data communications protocol. This service is used today by a few large businesses -- notably those with large groups of 800 service circuits. Dave Levenson Voice: (201) 647 0900 Westmark, Inc. Internet: dave@westmark.uu.net Warren, NJ, USA UUCP: {uunet | rutgers | att}!westmark!dave [The Man in the Mooney] AT&T Mail: !westmark!dave