Received: from MIT-Multics.ARPA by buit1.bu.edu (3.2/4.7) id AA19369; Mon, 15 Jun 87 22:29:32 EDT Date: Mon, 15 Jun 87 22:22 EDT From: "Roger A. Roach" Subject: TELECOM Digest V7 #11 To: telecom-request@BUIT1.BU.EDU Message-Id: <870616022252.112737@MIT-Multics.ARPA> Forum-Transaction: [0380] in the >site>arpa_mail_dir>Telecom meeting Transaction-Entered-By: Network_Server.Daemon@MIT-Multics.ARPA Transaction-Entered-Date: 4 Jun 87 19:39 EDT Status: RO From: jsol@buit1.bu.edu@buita TELECOM Digest Thu, 4 Jun 87 18:51:19 EDT Volume 7 : Issue 11 Today's Topics: Re: 9600 bps dialups (HST 9600) 9600 bps dialups (HST 9600) "890" and warning letter Re: bandwidth of LADS (metallic?) circuit Submission for comp-dcom-telecom Party line question Re: Cellular Fraud -- trivial 1-800-XXX-0000 ---------------------------------------------------------------------- Date: Tue, 2 Jun 87 21:12:55 EDT From: Michael Grant To: Gene.Hastings@H.CS.CMU.EDU, W8SDZ@SIMTEL20.ARPA Subject: Re: 9600 bps dialups (HST 9600) Cc: Info-Modems@SIMTEL20.ARPA, telecom@BUIT1.BU.EDU >It wouldn't surprise me if the HST becomes the defacto standard for 9600 baud. >--Keith Petersen I would be surprised. Even though I usually don't require more than 300 baud to type at a terminal, my systems support UUCP which wouldn't work very well with 300 baud in one direction. Do these modems do some sort of flow analys and adjust the speed accordingly? I feel that the only good 9600 baud modem is one that provides at least a full 9600 baud in both directions, with NO egregious delays. -Mike p.s. the Microcom MNP level 6 comes close. ------------------------------ Date: Tue, 2 Jun 1987 21:45 MDT From: Keith Petersen To: Michael Grant Cc: Info-Modems@SIMTEL20.ARPA, Telecom@BUIT1.BU.EDU Subject: 9600 bps dialups (HST 9600) The USRobotics HST 9600 modem assigns the 9600 baud direction to the end that is sending the most data. It should work fine with uucp. Most file transfer protocols have the receiving end sending only some kind of acknowledge or negative acknowledge (resent request) which usually consists of only a few characters. --Keith Petersen Arpa: W8SDZ@SIMTEL20.ARPA Uucp: {bellcore,decwrl,harvard,lll-crg,ucbvax,uw-beaver}!simtel20.arpa!w8sdz GEnie: W8SDZ RCP/M Royal Oak: 313-759-6569 - 300, 1200, 2400 (V.22bis) or 9600 (USR HST) ------------------------------ Date: Wed, 3 Jun 87 00:04:28 PDT From: jimmy@PIC.UCLA.EDU (Jim Gottlieb) To: telecom@buit1.bu.edu Subject: "890" and warning letter Someone mentioned that AT&T was adding a toll-free area code of 890. In fact, Bell of PA (and perhaps the other Bell Atlantic companies?) has created the toll-free *prefix* of 890. This would be accomplished through agreements with neighboring independent Telcos and appears to actually be a way for Bell Atlantic to offer a local toll-free service without involving AT&T. Personally, I don't think Telcos should be allowed to do this. The area code 800 is well established as a toll free prefix and the introduction of different toll-free prefixes in each area code will only add to customer confusion. Uniformity should not be sacrificed in favor of the Telco saving a few cents. A different someone mentioned a letter from Pacific Bell warning that a new switch was being installed. P*B has been routinely sending out these letters to those about to be converted (usually from crossbar) to a Northern Telecom DMS100 Digital switch. The switch has many quirks, but especially annoying is often a lack of CPC (Calling Party Control signal), though P*B has been adding this to the DMS switches. The letter is just for P*B to cover themselves ("We warned you!"). Telephone enthusiasts (and anyone else with an interest in communications) is invited to call the ESSug (ESS Users Group) on (714)973-2000 (300/1200bps) Jim Gottlieb ------------------------------------------------------------------------- ARPA: jimmy@PIC.UCLA.EDU UUCP: {ucbvax, sdcsvax!sdcrdcf!ucla-cs} !pic.ucla.edu!jimmy (this machine has no UUCP link) Tel. (213) 824-5454 ------------------------------ Date: Tue, 2 Jun 87 22:28 EDT From: Jeffrey Del Papa Subject: Re: bandwidth of LADS (metallic?) circuit To: hastings@morgul.psc.edu Cc: dyer@harvard.harvard.edu, telecom@buit1.bu.edu Date: Saturday, 30 May 1987 17:55:14 EDT From: Gene.Hastings@h.cs.cmu.edu We have several LADS lines in service, all at 56kbs, synchronous. There should be information available from the vendor of an arbitrary short-haul modem telling you what speed it can push how far (longer distance-> lower speed). We were frustrated and slightly amused when we called the person who was the official Point-of-Contact for our campus asking what the milage was on one of our lines and got the reply that they didn't know and had never heard the question before. Gene the easiest answer to this question is to simply short out the line and use an ohmmeter. the number is ~6k ohm/mile but look in the aprop telco documents for the exact number. (you could also use a TDR if you happen to have on hanging around... that is also the only easy way to be sure that they didn't leave the loading coils on the line.) ------------------------------ From: ssc-vax!clark@beaver.cs.washington.edu (Roger Clark Swann) Date: 3 Jun 87 23:18:40 GMT To: uw-beaver!comp-dcom-telecom@beaver.cs.washington.edu Subject: Submission for comp-dcom-telecom Path: ssc-vax!clark From: clark@ssc-vax.UUCP (Roger Clark Swann) Newsgroups: comp.dcom.telecom Subject: Party line question Keywords: pulse dialing, mechanical, electronic Message-ID: <1273@ssc-vax.UUCP> Date: 3 Jun 87 23:18:39 GMT Distribution: na Organization: Boeing Aerospace Corp., Seattle WA Lines: 27 **** jam for line eater **** I recently had a question for a friend that could not figure out: problem: electronic phone won't dial when connected to party line. My friend has a beach house with phone service being a party line. I don't remember if he said how many connections there are to the line, but he said that he DOES NOT get any rings other that his own. He normally has an WECO 500 style insturment on the line with no problems dialing or receiving calls. However, when he tried to hookup an 'electronic' (keypad with chip that generates dial pulses) phone the line, he could only dial about three digits before getting a re-order recording. He said that he could hear the 'clicks' as the pulses were being generated and they sounded OK. Someone can call in and the phone will ring and voice circuits are OK. (This same phone instrument works fine at his in town residence) The only thing I could think of was that the 'electronic phone was not pulsing at the correct speed. But then he told me that he tried hooking his modem to the line and making it pulse dial. The result was the same re-order recording. So, this makes me think that there is some strange configuration on this phone line or something??? Anyone have an idea as to what is going on here? Roger Swann uw-beaver!ssc-vax!clark [Any number of reasons could cause this problem. FCC regulations don't even *allow* you to plug in a modular instrument to a party line. --JSol] ------------------------------ Date: Thu, 4 Jun 87 03:53:18 PDT From: hoptoad.UUCP!gnu@cgl.ucsf.edu (John Gilmore) Subject: Re: Cellular Fraud -- trivial To: telecom@xx.lcs.mit.edu In article <8705312136.AA01347@mimsy.umd.edu>, mgrant@MIMSY.UMD.EDU (Michael Grant) writes: > The Electronic Serial Number is an 8 digit Hexidecimal number. It is not > easily changed. Both the MIN, (Mobil Id Number, your phone number) and the > ESN are sent out when you press the send key. Your MIN is easily changed > by reprogramming your phone, but the ESN is not easily changed. To change > your phone number, both the phone, and the cell system must be changed. The whole thing is pretty silly. Each unit has a serial number and the serial number is "supposed to be" impossible to change. Actually in many systems it is in a PROM in a socket, so no biggy. Even if it was impossible to change, it's not impossible to change the ROMs that hold the program that runs the phone, so you could always reprogram it to ignore the ROM. You could embed the whole phone in epoxy, but who would buy a $2000 phone that you have to throw away if any little thing breaks? The best deal would be to make a program ROM where if you put it in this mode, it would listen on the control channel for phones making calls or answering rings, and save away 10 or 20 of their phone number/ serial number pairs. Anytime you wanted to make a call, it would pick one at random and pretend to be that phone. The load on any individual's bill would be light enough that you'd be hard to catch. This would not let you receive calls for free, but I seem to recall some scheme for that, too. Geoff Goodfellow, Bob Jesse, and Andrew Lamothe published a paper on this in the November 1985 issue of Personal Communications Technology magazine (FutureComm Publications Inc., 4005 Williamsburg Ct., Fairfax, VA 22032, 703/352-1200). The cellular phone standard is called "EIA IS-3-B" though I think they recently upgraded it to "-C". You can get a copy from Global Engineering Documents (call 800 information). It is not lucid but it is readable if you flip around a lot and think about it. ------------------------------ Date: 04-Jun-1987 1311 From: cantor%delni.DEC@decwrl.DEC.COM (Dave C., 226-7726, LKG1-3/A06) To: telecom@buit1.bu.edu, telecom_digest%delni.DEC@decwrl.DEC.COM Subject: 1-800-XXX-0000 Ref message subj as above dtd Thu, 21 May 87 10:11 EDT from David Harpe, : >Completely by accident, I noticed the other day that if you dial 1-800-XXX-0000 >where XXX is a valid 800 exchange, you get the following message: > "You have reached the ATT long distance network. Thank you for > choosing ATT. This message will not be repeated." I checked a few codes and found a similar message. However, 800-444-0000, in particular, identified itself as the MCI long distance network. An article in Telecom Digest 5:156 mentioned that 800 NXX codes are equal access based and an article in TD 6:3 gave a list of the 800 NXX codes assigned to MCI. Also, I dialed 800-NXX-0000, where the particular NXX I used is the same as the one through which you reach my beeper. I found that it connects to a recorder machine, as though it were a regular telephone number. Using some other NXX codes for some of my colleagues' beeper numbers, I found that they seem to be regular beeper numbers. (No, I didn't actually send the beep, though.) It's likely that the beeper exchange numbers I called are not routed through any long distance carrier, and that New England Telephone allows NXX-0000 to be used as a regular number. Perhaps it is just a convention that both AT&T and MCI follow that 800-NXX-0000 produces the same message as 700-555-4141. Oh yes, it apparently doesn't matter what the default long distance carrier is. One of my lines is assigned to Sprint and the other to MCI. I got the same results using both of these lines. Dave C. (David A. Cantor) ------------------------------ End of TELECOM Digest *********************