bote@uunet.uu.net (John Boteler) (02/10/91)
Tom Lowe describes a costly and painful procedure for extracting
answer supervision from NJ Bell.
Although my suggestion may not meet his exact requirements, it does
work flawlessly for my voice response systems.
Solution: order CENTREX. That's it! No special tariffs, no unnecessary
pain (other than the usual CENTREX programming screw-ups), and you get
features as part of the deal. The answer supervision is provided as an
OSI (Open Switch Interval) at least on 3*Way calls, and possibly on
single outbound calls when served by a #1ESS. #5s and their ilk are
another question.
This comes in handy for several applications I have running right now;
after finding damn few PBX manufacturers which sell PBX providing loop
interrupt to the stations, I like CENTREX better every day.
[Author's Note: Would ground start circuits provide the signalling
desired? Since they are engineered circuits, it would seem that such
signalling could be provided without a lot of pain. I don't see DOD
trunks as being special: many PBXs are configured this way.]
John Boteler bote@csense {uunet | ka3ovk}!media!csense!bote
SkinnyDipper's Hotline: 703 241 BARE | VOICE only, Touch-Tone(TM) signallingdave@westmark.westmark.com (Dave Levenson) (02/11/91)
In article <74365@bu.edu.bu.edu>, csense!bote@uunet.uu.net (John Boteler) writes: > Tom Lowe describes a costly and painful procedure for extracting > answer supervision from NJ Bell. ... > Solution: order CENTREX. That's it! No special tariffs, no unnecessary > pain (other than the usual CENTREX programming screw-ups), and you get > features as part of the deal. The answer supervision is provided as an > OSI (Open Switch Interval) at least on 3*Way calls, and possibly on > single outbound calls when served by a #1ESS. #5s and their ilk are > another question. I would like to know what sort of central office John is talking about. Here in NJ, I have seen Centrex provided by 5 crossbar, 1ESS, 1AESS, and 5ESS. None of those switches routinely provide answer supervision to centrex subscriber lines. What all of these switches do provide is an open circuit interval (500 msec for ESS, ~100 msec for 5 crossbar) when the far end party disconnects. This is not supervision. This indicates an abandoned call, and is provided to the remaining party after the other party has disconnected, on both originating and terminating calls. Answer supervision, which indicates when the called party has answered, is provided under tarriff, and usually consists of a battery reversal toward the calling party when the called party answers. Dave Levenson Internet: dave@westmark.com Westmark, Inc. UUCP: {uunet | rutgers | att}!westmark!dave Warren, NJ, USA AT&T Mail: !westmark!dave Voice: 908 647 0900 Fax: 908 647 6857
john@zygot.ati.com (John Higdon) (02/15/91)
Dave Levenson <dave@westmark.westmark.com> writes: > What all of these switches do provide is an open circuit interval (500 > msec for ESS, ~100 msec for 5 crossbar) when the far end party > disconnects. This is not supervision. While very much a hack, it works like this: On a 1(A)ESS, if a line is furnished from a Centrex port, the three-way has a peculiar property. With the first call in progress, the Centrex party flashes the hook for a second dial tone. The call progresses and when it supervises there is an open loop signal AT THE MOMENT OF SUPERVISION. Actually, I find this most annoying. I add the second call to the connection and when it comes off hook, about 500 milliseconds later there is a big KA-PLUNK (the "supervision indication"). The problem with this hack is that you need a first call up before the trick works. In scummy Pac*Bell Land, that call must be supervised (or incoming) before you can even get three-way dial tone. So somebody somewhere has to be paying for that other call. It's a neat hack and it really does provide reliable supervision indication, but it is also a bit cumbersome. John Higdon | P. O. Box 7648 | +1 408 723 1395 john@zygot.ati.com | San Jose, CA 95150 | M o o !
john@zygot.ati.com (John Higdon) (02/16/91)
John Boteler <csense!bote@uunet.uu.net> writes: > [Author's Note: Would ground start circuits provide the signalling > desired? Since they are engineered circuits, it would seem that such > signalling could be provided without a lot of pain. I don't see DOD > trunks as being special: many PBXs are configured this way.] This prompts a question: Do other telcos (than Pac*Bell) always consider ground start lines to be design circuits? A number of posts over the years have seemed to carry that assumption. As far as Pac*Bell is concerned, ground start or loop start are simply alternative ways of supplying dial tone. They do not define PBX trunks, business service, or line conditioning. Any line of any COS can be either ground start or loop start, including residence. There is no extra charge for loop start, either for installation or monthly. However, converting a line from one to the other carries a charge roughly equivalent to the installation fee. Does "ground start" imply certain classes of service in other parts of the country? John Higdon | P. O. Box 7648 | +1 408 723 1395 john@zygot.ati.com | San Jose, CA 95150 | M o o !
kabra437@pallas.athenanet.com (Ken Abrams) (02/18/91)
In article <74365@bu.edu.bu.edu> csense!bote@uunet.uu.net (John Boteler) writes: >Although my suggestion may not meet his exact requirements, it does >work flawlessly for my voice response systems. >Solution: order CENTREX. That's it! No special tariffs, no unnecessary >pain (other than the usual CENTREX programming screw-ups), and you get >features as part of the deal. The answer supervision is provided as an >OSI (Open Switch Interval) at least on 3*Way calls, and possibly on >single outbound calls when served by a #1ESS. #5s and their ilk are >another question. I hope John doesn't build his business around this "hidden feature" that he thinks he has found because sometime in the near future it is likely to disappear. None of the modern digital switches produce an open-interval at the point that he is looking for it (can be arranged for open circuit at disconnect only). When John's LEC cuts him over to a digital switch, he will probably complain long and loud because some of his equipment doesn't work anymore. If you really need answer supervision, it is available with ground-start PBX lines in the form of a line reversal. There may be other solutions too but trying to interpret an open switching interval as answer supervision is a big mistake (IMHO); it will likely bite you in the backside later. Ken Abrams uunet!pallas!kabra437 Illinois Bell kabra437@athenanet.com Springfield (voice) 217-753-7965