Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!netsys!vector!nobody From: vances@egvideo.UUCP (Vance Shipley) Newsgroups: comp.dcom.telecom Subject: Re: General purpose, programmable phone switch Message-ID: Date: 4 Feb 89 05:00:00 GMT Sender: chip@vector.UUCP Lines: 34 Approved: telecom-request@vector.uucp X-Submissions-To: telecom@bu-cs.bu.edu X-Administrivia-To: telecom-request@vector.uucp X-TELECOM-Digest: volume 9, issue 49, message 4 In article AI.CLIVE@MCC.COM (Clive Dawson) writes: >More and more often over the last several months, we have seen >messages to TELECOM inquiring whether or not a box exists which >will do "x", where x is some function dealing with counting >the number of rings on a line, connecting two lines together >in various configurations, automatically answering, automatically >have to be mechanisms to detect busy signals, etc. (One thing I'm >not sure about is how to detect when a remote phone hangs up; is there >an in-band signal for this?) there is a device made by Mitel Datacom called the SMarT-1 (sic) which has precision tone detectors, DTMF generators, DTMF recievers, control (loop or ground start), as well as a bidirectional rs-232c port. it is quite flexible in programming and could be used to help you accomplish many different ideas. it was designed to handle complex routing situations using varied carriers. as for the 'detect when a remote phone hangs up' question, this is called CPC or 'Calling Party Control' and is often found on normal loop start lines. when a caller hangs up the circuit to the phone that was rung is reversed in polarity for a short period of time (milliseconds). many answering machines watch for this and reset when a caller hangs up. the trouble is that it is'nt part of a normal tarriffed service so you can't count on it. on a ground start line (as is used on a PBX) it is much simpler and _is_ an integral part of the service, when the other end hangs up, whether you called or answered, the loop is broken. >I suspect that all of this functionality exists in one form or another >in various answering machines, automatic dialers, call screening >boxes, etc. The question is, has anybody thought of putting it all >into a single box and making it programmable by the user? well the SMarT-1 is quite programable, but that would depend on the user :-) -vance shipley