Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!rutgers!netsys!vector!telecom-gateway From: westmark!dave@rutgers.edu (Dave Levenson) Newsgroups: comp.dcom.telecom Subject: Re: Centrex Message-ID: Date: 7 Apr 89 13:43:07 GMT Sender: news@vector.Dallas.TX.US Organization: Westmark, Inc., Warren, NJ, USA Lines: 37 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 129, message 9 of 11 In article , wmartin@st-louis-emh2.army.mil (Will Martin -- AMXAL-RI) writes: > The main fault I find with Centrex, in an operational, user-interface sense, >is the silly use-the-switchhook business to transfer calls and get another >line. > I would think that one of the touchtone buttons, like # or *, could be > sensed during a call to perform the action that is now controlled by the > switchhook. There are two reasons why touchtones are not recognized during conversation. One is economic: tone-detectors are more expensive then talking-links in the central office. If one had to be dedicated to every conversation, and not (as they are now) only when dialing is in progress, the central office would cost more. The other reason has to do with the present state-or-the-art in discriminating between voice and touchtone. If you listen to a conversation with a touch tone detector, you'll detect a number of apparent touch-tones in ordinary speech. Even more if there is background noise consisting of music at either end of the conversation. In most of the world outside North America, PBX switches use a "grounding button" where we tend to use a hook-flash to get the switch's attention. The switchhook always means disconnect. The momentary ground on one side of the loop begins the "consultation call/conference call/transfer call" sequence. While this is good for PBX use, central office services (including centrex) would probably be less reliable using this method, as outside plant ground faults would play havoc with the switching machine. -- Dave Levenson /-----------------------------\ Westmark, Inc. | If you can't give me your | Warren, NJ USA | Phone number, don't call! | {rutgers | att}!westmark!dave \-----------------------------/