Received: by bu-cs.BU.EDU (5.58/4.7) id AA26465; Tue, 31 Jan 89 04:43:51 EST Message-Id: <8901310943.AA26465@bu-cs.BU.EDU> Date: Tue, 31 Jan 89 4:25:00 EST From: The Moderator Reply-To: TELECOM@bu-cs.BU.EDU Subject: TELECOM Digest V9 #39 To: TELECOM@bu-cs.bu.edu TELECOM Digest Tue, 31 Jan 89 4:25:00 EST Volume 9 : Issue 39 Today's Topics: Re: Query about Telebit Re: 1+areacode Re: 1+areacode Re: When DDD Began Info on Cellular Telephones Cellular Data Comm. from a stationary phone Phones in the movies and on TV Ringback that just won't quit Don't blame Judge Greene Re: Victims of wrong numbers ---------------------------------------------------------------------- To: comp-dcom-telecom@ucbvax.Berkeley.EDU From: desnoyer@Apple.COM (Peter Desnoyers) Subject: Re: Query about Telebit Date: 30 Jan 89 19:31:09 GMT In article david%ms.uky.edu@E.MS.UKY.EDU (David Herron -- One of the vertebrae) writes: >In article boottrax@csd4.milw.wisc.edu (Perry Victor Lea) writes: > >> Do not use a Telebit modem on an amiga, that is if it's over 9600 baud. >>Amiga systems use as a standard US Robotics ONLY! I have never found a 9600 + >>baud system that operates with a US robotics. > >[...] But my understanding >with US Robotics modems is that even though they use V.29 there's >a couple of funny things they do that makes the modem basically only >useful with another USR modem. US Robotics COURRIER HST modems use a proprietary modulation scheme which looks like V.29 in the forward direction with a tiny bit of bandwidth down around 300 Hz for a 300 bps reverse channel without echo cancellation. (a scheme like this has been proposed for standardization, and has gone under the temporary name V.asm - asm for asymmetric.) It runs a hacked version of MNP, which you don't really want to turn off. It sounds like a good idea, but it loses because MNP, even for single characters, is just too slow over the 300bps channel. Telebits or ping-pong V.29 modems will give you much better response time. With the Telebit, it can spoof Kermit or UUCP, instead of having MNP fighting your transfer protocol to slow things down. There are a lot of things I haven't explained in this article, but I didn't want to write 5 or 10 pages. E-mail me if you want more discussion on the technical (as opposed to practical :-) merits of various modems. Peter Desnoyers ------------------------------ To: comp-dcom-telecom@rutgers.edu From: ron@ron.rutgers.edu (Ron Natalie) Subject: Re: 1+areacode Date: 30 Jan 89 21:33:06 GMT > It's obvious we're running out of area codes, simply because new services > open up more phone numbers. In the beginning, for example, there was > Centrex. So, instead of a medium office building having 20 phone lines > (and phone numbers), with an operator switching calls in the building, > the building may still have only 20 phone lines to the outside, but > could be using 200 phone numbers for each of the inside phones. What you're describing is NOT Centrex. Centrex runs a line from the CO to each phone. You are describing the traditional PBX with DID. -Ron ------------------------------ To: telecom@bu-cs.bu.edu Subject: Re: 1+areacode Date: Mon Jan 30 19:25:12 1989 From: tanner@ki4pv (Dr. T. Andrews) The explanation that the "1+" enable distinguishing between area codes and exchanges is nice, but not entirely clear. Consider North Jersey. One site I call there has an exchange of 615. Another site I call has an area code of 615. (From here, no problem. I supply the area code before the 615 exchange.) In NJ but out of the local area for dialing exchange 615, what happens when the machine dials 1+615 ... ? Does it ring through after 4 more digits, or does it wait for 7 more? (Does it have a time-out in case only 4 follow?) --- ...!bikini.cis.ufl.edu!ki4pv!tanner ...!bpa!cdin-1!cdis-1!ki4pv!tanner or... {allegra killer gatech!uflorida decvax!ucf-cs}!ki4pv!tanner ------------------------------ Date: Sun, 29 Jan 89 22:21:02 EST From: harvard!ima.ISC.COM!johnl (John R. Levine) Subject: Re: When DDD Began In article telecom@bu-cs.BU.EDU (TELECOM Moderator) writes: >I think it is safe to say by the middle sixties DDD was pretty much a part >of American telephony. With the exception of Nevada toll stations, of >course, and the one place in Maine which kept its old fashioned service >for a few more years. I thought that Catalina Island, offshore near Los Angeles, had a manual exchange until about 1978. It was reputed to be the Bell System's last manual exchange. Regards, John Levine, johnl@ima.isc.com [Moderator's Note: I don't know when Avalon, CA (the town on the island) went dial. Was it as late as 1978? What about Martha's Vineyard, MA and Nantucket Island, MA? I know Vineyard Haven and Edgartown had manual service until sometime around the early seventies. PT] ------------------------------ To: comp-dcom-telecom@uunet.UU.NET From: dauksa@ecf.toronto.edu (Linas P Dauksa) Subject: Info on Cellular Telephones Date: Mon, 30 Jan 89 20:47:50 EST I am preparing a presentation on Cellular Telephones and am having difficulty finding technical information on the subject. The purpose of my presentation is to explain to a "layman" how a cellular telephone and the cellular network function. I would appretiate any references to books or periodicals that may be out there. Any information would be greatly appretiated. ------------------------------ To: husc6!comp-dcom-telecom@husc6.harvard.edu From: soi!sam@husc6.harvard.edu (Sam Lipson) Subject: Cellular Data Comm. from a stationary phone Date: 30 Jan 89 05:36:36 GMT I've read the discussion of cell-switch delays that was recently posted to this group, and I'm wondering what guarantees you have when you're stationary that you won't get switched to another cell. Presumably if there's no cell switching going on, you should be able to use a normal (i.e. not designed for cellular use) modem to send bits. Would this work? Is signal strength a good indication of whether you're safe from hand-off? Please send replies by mail, I'm suumarize if there's interest. Sam Lipson Software Options harvard!soi!sam soi!sam@harvard.harvard.edu ------------------------------ Date: Mon, 30 Jan 89 12:28:58 PST From: laura_halliday@mtsg.ubc.ca To: telecom@bu-cs.bu.edu Subject: Phones in the movies and on TV I saw something interesting in a TV show the other day. A lawyer, finding his client dead of a drug overdose didn't pick up the phone and dramatically say ``Operator, get me the police'' - he dialed 911 instead. This was the first time I've ever noticed a movie or TV character do this. Could this be the result of phone company pressure? I find it difficult to believe that producers would voluntarily give up a few seconds of drama unless they were forced to. The subliminal advertisers who place products in movies (e.g. Reese's Pieces in _E.T._) seem to be missing out on a new gold mine. Imagine the possible effect on AT&T's long distance business if the hero in a hit movie could be (conspicuously) seen dialing 10288 in the course of phoning somebody... - laura ------------------------------ Date: Mon, 30 Jan 89 08:20:12 EDT From: eli@ursa-major.SPDCC.COM (Steve Elias) To: telecom@bu-cs.bu.edu Subject: Ringback that just won't quit 10 or 15 years ago, in a suburban boston exchange, a friend and i discovered ringback codes... 981-xxxx worked in our area... here's where things get strange: sometimes the ringback just would not stop. you could pick up the phone, leave it offhook for a minute, hang up -- and the ringback would start again... and even stranger: sometimes, the ringback would be a continous ring -- not the normal intermittent bell. this didn't happen very often... steve elias (eli@spdcc.com) ------------------------------ Date: Mon, 30 Jan 89 09:39:09 -0500 (EST) From: Marvin Sirbu To: TELECOM@bu-cs.bu.edu Subject: Don't blame Judge Greene Peter Pavlvcik complains about ITI providing misleading information regarding pay telephone charges and service and the Moderator suggests Peter write to Judge Greene. Don't waste your time. The outrageous charges are the result of policy decisions taken by the FCC prior to divestiture (e.g. deregulating resale). If you want to complain to anyone, it should be to the FCC or to the local PUC. I note that ITI has been banned from operating in Ohio by the Ohio PUC because of the type of misleading practices Peter describes. Marvin Sirbu Carnegie Mellon University internet: ms6b+@andrew.cmu.edu bitnet: ms6b+%andrew@CMCCVB [Moderator's Note: But it was Harold who opened the door to this kind of abuse. Certainly the FCC played a role in it; but everyone, including the FCC, took the lead from His Onery, Judge Greene. PT] ------------------------------ Date: Mon, 30 Jan 89 01:01:28 EST From: levitt@zorro.FIDONET.ORG (Ken Levitt) Subject: Re: Victims of wrong numbers To: telecom@bu-cs.bu.edu In our town there were two exchanges, 655 and 653. After having one of our numbers for 9 years, we suddenly started getting numerous wrong numbers. It turned out that a new catalogue showroom store had just opened and had the 653 number corresponding to our 655 number. When I complained to the store manager, he suggested we change our phone number. I told him that we had been using our number for 9 years and he had been using his for two weeks but this failed to convince him to change his number. I also pointed out that he would be loosing a lot of business if many of his calls were routed to an unfriendly phone number. Nothing changed his mind. Many of the calls were similar to ones reported in previous Telecom Digests and I did find myself takeing phone orders for merchandise. Usually I just told people that we don't take phone calls and hung up. Finally, I changed the message on our answering machine to a very generic one and left the machine on all of the time. One of the funniest messages that I ever got was from one of the store's employees saying that he would not be into work that day. After two years of this the store went out of business. All was quiet for a year or so and then we started getting a lot of calls for Tommy. The calls came at strange hours, the people sounded kind of spacey, and even though there seemed to be a wide variety of people calling when I answered the phone, no one ever left a message on the machine. I came up with a theory that Tommy must be a drug dealer. For a while when people called for Tommy, I told them that he wasn't in and asked them if they wanted to leave a message. No one would ever leave a message. Then the calls died down and I forgot about Tommy until this week when we found a message on the machine saying "Tommy, this is your mom, please call me.". You would think that Tommy's mom would be able to tell that the voice on the tape was not Tommy's. Ken Levitt FidoNet: 1:16/390 (Mail accepted 01:30-07:00 est) UUCP: ...harvard!talcott!zorro!levitt INTERNET: levitt%zorro.uucp@talcott.harvard.edu ------------------------------ End of TELECOM Digest *********************