euatdt@euas11g.ericsson.se (Torsten Dahlkvist) (08/24/89)
Hmm. An interesting thought just struck me. There's been some talk about Calling Number Information on this meeting and some about ISDN. Because I used to work with ISDN and the first time I heard of CNI was there, I just naturally assumed they were linked. That is, I thought the subscribers beeing offered CNI were field-trial ISDN customers. But when I look at the numbers of subscribers quoted as potential CNI customers it certainly doesn't look like any field trial any more. Or somebody is manufacturing one HELL of a lot of stuff which I haven't heard about. So I started thinking about other solutions and something soembody said about signal bursts made me realize that it should be possible to send some sort of digitally encoded data on the phone line between the ring pulses to convey the necessary information. Is this what's being done? If so, how much do they send out? Is it just a field of "display data" that is shown on the user's display or does the receiving unit contain additional "intelligence" so that it can select specific fields of information from the burst? Could this kind of encoding be used to convey additional information to the receiving party? Like if a certain sequence of *'s and #'s was dialled with the subscriber number they'd get carried along and sent to the receiving party along with the CNI. That way you'd give the users a whole bunch of ISDN-like features at a much lower cost. Is this another example of the evolution of an older product continuing during the development of a newer one so that the advantages of the newer one aren't all that great when it finally hits the market? Will the struggle between ISDN and analog lines with digital add-ons be as fierce as that between MicroChannel and the extended AT-bus? It seems to me that the technical aspects of this issue must have been covered before the political problems were brought into the discussion so I probably just missed the beginning of it when I first started following News. If the topic has been covered and somebody can summarize it in a mailing to me then I'd be very grateful. /Torsten Torsten Dahlkvist ELLEMTEL Telecommunication Laboratories P.O. Box 1505, S-125 25 ALVSJO, SWEDEN Tel: +46 8 727 3788 [Moderator's Note: Watch your mailboxes for a special edition of the Digest to be issued Saturday devoted to a lengthy article on ISDN. PT]
deej@bellcore.bellcore.com (David Lewis) (08/30/89)
In article <telecom-v09i0323m03@vector.dallas.tx.us>, euatdt@euas11g.ericsson. se (Torsten Dahlkvist) writes: > An interesting thought just struck me. There's been some talk about Calling > Number Information on this meeting and some about ISDN. Because I used to > work with ISDN and the first time I heard of CNI was there, I just naturally > assumed they were linked. That is, I thought the subscribers beeing offered > CNI were field-trial ISDN customers. But when I look at the numbers of > subscribers quoted as potential CNI customers it certainly doesn't look > like any field trial any more. Or somebody is manufacturing one HELL of > a lot of stuff which I haven't heard about. What most people are talking about is CLASS (SM), Custom Local Area Signaling Services. The CLASS package of services makes use of Signaling System 7 common channel signaling to transmit Calling Party Number from the originating end office to the terminating end office. The terminating end office extracts the CPN from the SS7 Initial Address Message (IAM) and does whatever actions are necessary, based on that calling party number and called party number, to provide the particular service. In the case of CPN Delivery, aka Caller*ID or whatever (Calling Number Identification, in ISDN terms), it sends the calling party number to the user in the gap between the first and second rings, using a special signaling protocol which I'm not that familiar with. (and can't find offhand.) > ...how much (information) do they send out? Is it just a > field of "display data" that is shown on the user's display or does the > receiving unit contain additional "intelligence" so that it can select > specific fields of information from the burst? It's just Calling Party Number -- there's no "user-to-user signaling", just "network to user" signaling. Of course, there's nothing to say you couldn't develop CPE to take the calling party number and do all sorts of things with it -- call screening, database lookup (sometimes called "account match"), etc., etc... -- David G Lewis ...!bellcore!nvuxr!deej "If this is paradise, I wish I had a lawnmower."