Return-Path: Received: by massis.lcs.mit.edu (8.7.4/NSCS-1.0S) id XAA07120; Fri, 17 Oct 1997 23:33:03 -0400 (EDT) Date: Fri, 17 Oct 1997 23:33:03 -0400 (EDT) From: editor@telecom-digest.org Message-Id: <199710180333.XAA07120@massis.lcs.mit.edu> To: ptownson Subject: TELECOM Digest V17 #285 TELECOM Digest Fri, 17 Oct 97 23:33:00 EDT Volume 17 : Issue 285 Inside This Issue: Editor: Patrick A. Townson New C.O. in Madison, WI (Tad Cook) Book Review: "Doing More Business on the Internet" by Cronin (Rob Slade) Book Review: "Advancing HTML: Style and Substance" (Rob Slade) Answer Supervision? (Doug Terman) Re: Question re: ROLM CBX (Tom Watson) Re: Question re: ROLM CBX (Bill Ranck) Re: Question re: ROLM CBX (John Saxe) Re: Question re: ROLM CBX (John R. Levine) Re: New Cellular Phone Experience So Far (Peter Simpson) Re: New Cellular Phone Experience So Far (Bill Walker) TELECOM Digest is an electronic journal devoted mostly but not exclusively to telecommunications topics. It is circulated anywhere there is email, in addition to various telecom forums on a variety of public service systems and networks including Compuserve and America On Line. It is also gatewayed to Usenet where it appears as the moderated newsgroup 'comp.dcom.telecom'. Subscriptions are available to qualified organizations and individual readers. Write and tell us how you qualify: * telecom-request@telecom-digest.org * The Digest is edited, published and compilation-copyrighted by Patrick Townson of Skokie, Illinois USA. You can reach us by postal mail, fax or phone at: Post Office Box 4621 Skokie, IL USA 60076 Phone: 847-727-5427 Fax: 773-539-4630 ** Article submission address: editor@telecom-digest.org ** Our archives are available for your review/research. The URL is: http://telecom-digest.org They can also be accessed using anonymous ftp: ftp hyperarchive.lcs.mit.edu/telecom-archives/archives (or use our mirror site: ftp ftp.epix.net/pub/telecom-archives) A third method is the Telecom Email Information Service: Send a note to archives@telecom-digest.org to receive a help file for using this method or write me and ask for a copy of the help file for the Telecom Archives. ************************************************************************* * TELECOM Digest is partially funded by a grant from the * * International Telecommunication Union (ITU) in Geneva, Switzerland * * under the aegis of its Telecom Information Exchange Services (TIES) * * project. Views expressed herein should not be construed as represent-* * ing views of the ITU. * ************************************************************************* Finally, the Digest is funded by gifts from generous readers such as yourself who provide funding in amounts deemed appropriate. Your help is important and appreciated. A suggested donation of twenty dollars per year per reader is considered appropriate. See our address above. Please make at least a single donation to cover the cost of processing your name to the mailing list. All opinions expressed herein are deemed to be those of the author. Any organizations listed are for identification purposes only and messages should not be considered any official expression by the organization. ---------------------------------------------------------------------- Subject: New C.O. in Madison, WI Date: Fri, 17 Oct 1997 00:00:17 PDT From: tad@ssc.com (Tad Cook) New Ameritech Switching Center Opens in Madison, Wis. By Judy Newman, The Wisconsin State Journal Knight-Ridder/Tribune Business News Oct. 17 -- Ameritech customers probably never missed a dial tone, but as of this week, their calls are now being handled by a sophisticated new switching center in Madison that cost $4.5 million, used one million feet of wire and took nearly six months to install. Picture the stacks in the University of Wisconsin Memorial Library, with row after row, floor upon floor of huge racks filled with books. That's what the old telephone equipment looked a bit like at the Ameritech switching center in downtown Madison. Wires and relay devices jammed the racks instead of texts and treatises, filling two floors of the seven-story building near the Capitol Square. Each time a customer made a phone call, a relay activated, making for thousands of constant clicking sounds. "This floor would just be banging away," said Ned Burkhalter, field operations group manager. The old equipment, containing 43,000 telephone lines, was installed starting in 1969. It worked in tandem with manual operators with cord switchboards, the kind satirized by comedienne Lily Tomlin's "Ernestine" character, who connected toll calls to rural parts of Dane County and the state until the mid-1970s. Each time a new service option was added, such as call-waiting, more hardware was shoved into the racks, Burkhalter said. That entire function, the switching center for 43,000 Ameritech lines from phones in downtown Madison, is now housed in a single cabinet bay, 41 feet long. It looks more like a line of lockers at a health club. It is the "central brain" for every phone call made into or out of the central city, except for government and UW offices. Beside it are seven additional cabinets. These coordinate calls that originate or terminate throughout the 608 area code, including those from long-distance carriers. They are sleek, smaller and modern because the system is now entirely digital, said Randy Pickering, director of customer business services. And if customers add new features, such as Caller ID or three-way calling, they're just programmed inside the switch. "It's all in the software," Pickering said. The modernized equipment needs only two employees to oversee it, half as many as the older version, Burkhalter said. The Downtown facility is the last of the six switching centers in Madison to go digital, and the most complicated, since it also houses equipment for the entire area code. Similar centers around the state also are in the process of digital conversion, which is expected to be completed by the end of 1998. And what happens to the miles of now-outdated phone wires and relays? They go to recycling centers, where the copper and gold they contain will be extracted. Ameritech could get $35,000 for the scrap metal, Burkhalter said. "We can recover quite a bit of money from a center like this," he said. ------------------------------ Date: Fri, 17 Oct 1997 10:37:52 EST From: Rob Slade Subject: Book Review: "Doing More Business on the Internet" by Cronin BKDBSINT.RVW 970401 "Doing More Business on the Internet", Mary J. Cronin, 1995, 0-442-02047-3 %A Mary J. Cronin %C 115 Fifth Ave., New York, NY 10003 %D 1995 %G 0-442-02047-3 %I Van Nostrand Reinhold %O 800-842-3636 212-254-3232 fax: 212-254-9499 jjeng@vnr.com kydel@vnr.com %P 368 %T "Doing More Business on the Internet: How the Electronic Highway is Transforming American Companies" If not the original Internet business book, Cronin's "Doing Business on the Internet" is very close to it. Having suffered through dozens of ill-advised and basically ignorant tomes on the same subject, I approached this one with some trepidation. (Despite the difference in title, this is, essentially, a second edition.) I am left with a surprising question: with this very solid guide as a model, how did those other turkeys get so far off track? Cronin does not demonstrate a personal familiarity with the net, but the book is a compilation of experience from those with an Internet background. Solid advice is provided from those who have succeeded and, sometimes, those who failed. The orientation is businesslike, even in terms of net history. The material is comprehensive, covering everything from connectivity to personal use of the resource by employees. In the intervening years since the first publication, some of the examples have failed, and some have evolved. Gopher and WAIS (Wide Area Information Server) have taken a back seat to the Web, which now, at least, gets mentioned. Overall, though, this is still a classic reference for commercial activity on the net. copyright Robert M. Slade, 1997 BKDBSINT.RVW 970401 roberts@decus.ca rslade@vcn.bc.ca slade@freenet.victoria.bc.ca link to virus, book info at http://www.freenet.victoria.bc.ca/techrev/rms.html Author "Robert Slade's Guide to Computer Viruses" 0-387-94663-2 (800-SPRINGER) ------------------------------ Date: Thu, 16 Oct 1997 10:39:57 EST From: Rob Slade Subject: Book Review: "Advancing HTML: Style and Substance" BKW3JI21.RVW 970401 "Advancing HTML: Style and Substance", World Wide Web Consortium, 1997, 0-56592-264-6, U$29.95/C$42.95 %A World Wide Web Consortium %C 103 Morris Street, Suite A, Sebastopol, CA 95472 %D Winter 1997 %E Rohit Khare khare@w3.org %G 0-56592-264-6 %I O'Reilly & Associates, Inc. %O U$29.95/C$42.95 800-998-9938 707-829-0515 fax: 707-829-0104 nuts@ora.com %P 254 p. %S World Wide Web Journal, Vol. 2, Issue 1 %T "Advancing HTML: Style and Substance" Not having a TV, I haven't seen the ad that has two geeks enthusing over dancing images and flaming fonts on the net, until they finally realize that neither has ever used any of these "kewl" sites. I can, however, fully sympathize with the sentiment being expressed. In fact, I was recently asked by this very company to comment on one of their Web sites, and pointed out that Lynx users were confronted by a column of uninformative "[IMAGE]" tags and not much else. So, I can heartily recommend those articles in this issue which anticipate the Sixth International World Wide Web Conference's theme of accessibility: those on usability, access for disabilities, and appropriate uses. So much for the substance part of the title. Many authors raced HTML (HyperText Markup language) 3.2 titles into print in anticipation of the official adoption of the standard. The pieces in this issue (particularly the overview by Musciano) at least have an official sanction. The specification for Cascading Style Sheets (CSS) has been less heavily promoted but may be more significant. As usual, there are other matters dealt with, such as the new Opera and Amaya browsers, and MNG (Multiple image Network Graphics). copyright Robert M. Slade, 1997 BKW3JI21.RVW 970401 DECUS Canada Communications, Desktop, Education and Security group newsletters Editor and/or reviewer ROBERTS@decus.ca rslade@vanisl.decus.ca BCVAXLUG Envoy http://www.decus.ca/www/lugs/bcvaxlug.html ------------------------------ Date: Fri, 17 Oct 1997 11:38:28 -0400 From: Doug Terman Subject: Answer Supervision? Dear Telecom Gurus, We have a T-1 which runs to a first tier carrier's POP. We are running a particular application that, based on an email msg., triggers our equipment to dial an overseas number through our switch. Once connected, our equipment calls -- again through our switch -- a second telephone number here in the States which has a database our client is trying to access. The two calls are then conferenced together by our switchgear. (I might add, however, this conferenced connection could be just an ordinary voice call and it's not relevant that we're feeding data to the overseas party.) Normally, in the past (about 20 days ago), when the line overseas was manually hung up, our equipment waited for a disconnect signal -- I believe what is called, "the bits go high." Typically, this signal arrived at our equipment about 13 seconds after the connection overseas was hung up. This then signaled our connection to the US number that was feeding data to also hang up. Both connections were then broken. However, starting sometime around the 20th of October, an inspection of our switch's call-progress logs showed that from the time the overseas party actually hung up until our equipment got the "bits go high" signal had magically increased from 12 to 32+ seconds. Just to insure that it was not the foreign PTT who had increased the timer from 12 to 32 seconds, I placed a couple of calls through another carrier on a POTS line. No problem. I got the reorder tone in 12 seconds. So what's going on? Is my wonderful first tier carrier "padding" the call by delaying "all bits go high" for another 15 to 20 seconds after receiving it from the foreign PTT? After all, since I'm still connected, even though the called party has hung up, so I'm paying for that connect time, even though no "information" is being converyed. I fully understand that answer supervision isn't "immediate" line cutoff when the called party hangs up, and I could live with 12 seconds, but I can't live with 32 seconds. Not with 100,000 minutes a month worth of international billing. Normally, I'd ask that any respondents reply directly to my email address, but this might be highly educational for the telco-savy- impaired listers (myself included) among us. Best to all, Doug Terman Operations Manager Antilles Engineering, Ltd. Tel. (802) 496-3812 Fax. (802) 496-3814 Snail Mail: PO Box 318 Warren, VT 05674 ------------------------------ From: tsw@cagent.com (Tom Watson) Subject: Re: Question re: ROLM CBX Date: Fri, 17 Oct 1997 11:35:32 -0700 Organization: CagEnt, Inc. In article , ldecours@frontiernet.net (Lincoln DeCoursey) wrote: > My employer, a 50+ store grocery chain in western New York has a PBX > in each location to handle in-store phone communication, as well as > dial-in and dial-out. Additionally, the stores and offices are > networked together in that from any phone in any of these systems, you > can dial any given phone in any one of the systems by dialing > 80-SS-XXX where SS is the store number and XXX is the extension to > dial in that store. > The phones utilized are standard AT&T analog phones. Each has a > sticker on it which identifies the system as "ROLM CBX," and contains > general instructions for picking up calls, transfering calls, holding > calls, parking calls, etc. > My question deals with the interconnectivity in the system and how it > is achieved. I am unsure whether calls made to other premises are > carried over the analog telco lines, or if there is some leased line > implementation for the system, but I am intrigued by the ability to > directly ring any given phone in any system. I would speculate that > each system has an incoming line which picks up and then accepts some > instruction (perhaps DTMF) as to the destination extension. My caller > ID identified the number which the system used to generate an outgoing > call from the system to my house. In redialing this number, I get a > high pitched tone upon connection. > I'd like to be able to identify how this interconnectivity works, and > how to get into a location's system through this back-door, as opposed > to the published phone number which connects to the receptionists. > Any resources or instruction would be greatly appreciated. Three answers: For the caller ID thing: I suspect that outbound from the PBX is directed to trunk lines that are "one way" configured in the PBX. When you get a call from the PBX, it goes out on these trunks which are different from the inbound trunks that are listed in the phone book. Upon calling these trunks back, you may get into the maintence area of the PBX, or a modem external (even internal) that picks up instead of the PBX. For the dial '80...' thing. What happens is that every store has an internal program that absorbs the store number and the extension. Based on the store number it picks a trunk. If the two stores are directly connected, it siezes the trunk, and forwards the station number down the line. The receiving PBX takes the digits (on the "tie trunk") and connects to the station requested. If the two stores aren't connected, the PBX probably routes the whole thing to a PBX that is further up the org chart (home office?) which is connected to the store in question. The procedure continues from there. Mostly it is a matter of setting up the routes for a given dial pattern. Back doors. It depends. Sometimes there is an outside number that answers and gives out the "dial tone" of the PBX. You then dial into it as an "extension". At times these ports need passwords (4 digit numbers). Since these ports (there is a fancy name for them I don't remember) allow one to (possibly) dial out of the PBX, they are not typically given to anyone but those "in the know". Sometimes experimentation (and possibly social engineering) can yield these. As always "use with care" because if something goes wrong, YOU will be blamed for the problem (experience here!!). tsw@cagent.com (Home: tsw@johana.com) Please forward spam to: annagram@hr.house.gov (my Congressman), I do. [TELECOM Digest Editor's Note: I think you are referring to 'DISA' which means Direct Inward Service Access' or something like that. And believe me you, those backdoors can be a real can of worms or nest of hornets if the 'wrong person(s)' find out about them. If they are present in your application, change the password on a very regular basis. United Airlines, based here in the Chicago area, had a backdoor into 'Unitel' which was their corporate phone network back in the 1970-80's. By dialing a seven digit number in the north- west suburbs of Chicago, you got dialtone returned to you from the corporate switch. No passwords required to use it ... nothing. Just start dialing. There were *dozens* of three-digit 'tie-line' codes which gave connection to the tie-lines between the corporate office and airports all over the USA. Once on the centrexes (in some cases, and PBXs in other cases) at those airports, one could then dial '9' and go out locally as desired. Most of them had WATS lines accessible with some code, however you could also use corporate's WATS lines without bothering to first grab a tie-line to one of the branches. In addition to '9' at corporate level which did almost nothing outside the town of Elk Grove, IL where it was located, corporate had metro lines for Chicago, FX lines for New York, Denver and a couple other places, all the aforementioned tie-lines to airports everywhere, their own set of WATS lines, etc. Pick any three digit number off of that back door dialtone it seems, and you got a new dial tone from somewhere. A couple of phreaks sat down and actually charted it all out, making a list of every three digit code and where it went. In a few cases the only way they could tell was by dialing three digits off of the back door dialtone, getting a new dialtone, dialing the 0 operator and asking 'who are you?' ... and some of the responses were downright strange. One code connected to a sort of bizarre, old-fashioned dial tone which then would only accept two digits. They never could get an answer no matter what two digits they dialed, nor from dialing the operator. Finally one day, one of the calls there got answered by someone saying 'hello'; they had reached an aircraft hangar in Nevada somewhere which according to the person answering the phone was not occupied 'very much' or used regularly. Then one tie-line code allowed dialing '0' and the operator who answered said she was the operator at 'city hall, in Reno, Nevada'. Why a tie-line from United's corporate office to city hall in Reno? I have no idea. Almost every one of the airports reachable via a three digit tie-line code themselves had tie-lines going various interesting places. Some were just tie-lines back to corporate, but others went to things like the local Federal Aviation Administration's offices. Off of the centrex at the airport in Seattle one code produced a dialtone to which when dialed an operator responded 'Boeing Aircraft, may I help you?' Checking out her tie-lines (reached by dialing the tie-line from Seattle airport to Boeing) got various Boeing sales offices in the USA; got a dialtone that was later identified as 'Canadian WATS', and a few other charming things. If you went out from one of the airports to the FAA's centrex, there would always be a few tie-lines waiting for you there. Generally the audio quality stayed good for about three levels deep; that is you were able to break the dial tone with accuracy to about the third tie-line down in the web; from the corporate back door to an airport to something else beyond that. As a comparison, imagine today's World Wide Web and all the links you might visit, and every link offers a few more links at the press of a couple keys. That was Unitel; dial any link you wanted and there were always a couple more at the distant end waiting to be examined. **And no passcode at all on the backdoor**. Just wide open; because I suspect the executives at UAL would have been burdened having to learn a passcode. The first order of business on discovering this fountain of comm- unications potential was to detirmine *what number* was used for the outgoing side of the extender. Both the incoming side and the outgoing side were simply centrex extensions at corporate. That was easily detirmined by placing a call out to 9-0+ some long distance number; telling the operator to make it person to person to a fictious name, and requesting that she 'leave word' if the party was unavailable. The operator called the number, asked for Mr. Jones, and on not reaching him told the person answering to leave word for him to call 'Operator 7 in Chicago' (meaning charge the number being called) and ask for (phone number). Thank you operator, now the phone nunmber for the outgoing side of the extender is known. So after a few months, when the simpletons finally came to the conclusion their extender was being abused what did they do to thwart the phreaks? Simply flip it around and reverse the inbound and outbound lines. Of course, when the phreaks saw they were no longer getting an answer -- just open ringing -- from the number they had been using, they started dialing the other number instead and were 'back in business' the same day. Finally security people at Illinois Bell got involved after a couple million dollars in fraud calls had gone through. IBT made an example of a couple phreaks and told United to get their act together also. Shortly after that Unitel underwent a major overhaul. The old system known as 'progressive dialing' (one dialtone leads to the next dialtone) was abandoned in favor of a new computer which required not only a passcode (easy enough to obtain by social engineering) but also a full seven digit number before it would go away silently and act on your request before opening the talk path. The airports all had three digit prefixes of the form '732' (as in SEAttle) and '673' (as in ORD/Ohare) followed by four digit extensions, and no more jumping off at the distant end, thank you, and using *their* 9-level or *their* WATS. There were in the 1970-80's some absolutely unmitigated disasters where phreaks and 'WATS extenders' were concerned. Every major corporation was hit with millions of dollars in fraud. General Motors took it very hard as did United States Steel, Montgomery Ward and others. It is rare you see one these days, but in the event your company actually uses them, I can only recommend *extreme* caution in where they connect and who is allowed to get near them. PAT] ------------------------------ From: ranck@joesbar.cc.vt.edu (Bill Ranck) Subject: Re: Question re: ROLM CBX Date: 17 Oct 1997 12:38:55 GMT Organization: Virginia Tech, Blacksburg, Virginia Lincoln DeCoursey (ldecours@frontiernet.net) wrote: > can dial any given phone in any one of the systems by dialing > 80-SS-XXX where SS is the store number and XXX is the extension to > dial in that store. > The phones utilized are standard AT&T analog phones. Each has a > sticker on it which identifies the system as "ROLM CBX," and contains > general instructions for picking up calls, transfering calls, holding > calls, parking calls, etc. Are you *sure* those are standard AT&T analog phones? I ask because my university has a Rolm CBX and the phones are definitely not standard analog phones, although it is possible to have analog lines in the system so maybe you are correct. > My question deals with the interconnectivity in the system and how it > is achieved. I am unsure whether calls made to other premises are > carried over the analog telco lines, or if there is some leased line > implementation for the system, but I am intrigued by the ability to > directly ring any given phone in any system. I would speculate that > each system has an incoming line which picks up and then accepts some > instruction (perhaps DTMF) as to the destination extension. My caller I doubt your speculation. We have several switches on campus, and one or two located on the other end of the state, and the interconnects between them are all dedicated. In the case of the off campus nodes it is via a leased line (T1 or better I think). Your system is probably similar. > ID identified the number which the system used to generate an outgoing > call from the system to my house. In redialing this number, I get a > high pitched tone upon connection. What the switch presents as caller-ID info is programmable in the switch. It may bear no relation to anything. > I'd like to be able to identify how this interconnectivity works, and > how to get into a location's system through this back-door, as opposed > to the published phone number which connects to the receptionists. > Any resources or instruction would be greatly appreciated. What, does this newsgroup look like alt.2600 to you? Bill Ranck +1-540-231-3951 ranck@vt.edu Virginia Polytechnic Institute & State University, Computing Center ------------------------------ Date: Fri, 17 Oct 1997 09:08:15 -0400 From: John Saxe Subject: Re: Question re: ROLM CBX Why am I reminded of the time I headed off our receptionist from transferring a call to "extension 10xxx"? This sounds like a cracker surfing for a dial tone to me. ------------------------------ Date: 17 Oct 1997 02:58:16 -0000 From: johnl@iecc.com (John R. Levine) Subject: Re: Question re: ROLM CBX Organization: I.E.C.C., Trumansburg, N.Y. In article you write: > My employer, a 50+ store grocery chain in western New York has a PBX Hmmn, Wegmans? Or maybe Tops? > I'd like to be able to identify how this interconnectivity works, and > how to get into a location's system through this back-door, as opposed > to the published phone number which connects to the receptionists. > Any resources or instruction would be greatly appreciated. It sounds like they're using a system known as DISA (Direct Inter System Access or something like that.) When you call a DISA number, it answers with a tone at which point you, or more typically a calling PBX, send a DTMF passcode followed by the extension number desired. It's a very common facility used to allow direct extension dialing among PBXes in multiple locations, since it can use regular phone lines with no special features from the telco. It's also a notorious security hole since far too often the DISA passcodes are short and easily guessed, and the class of service on DISA trunks not properly restricted so that once you've entered the passcode you can dial 9 and then call outside anywhere. Some people consider this a feature so that employees working at home can call the PBX and then make business-related toll calls through the PBX at the company's direct dial rate, but phone hackers love to look for DISA ports to abuse for outdial to exciting foreign countries. John R. Levine, IECC, POB 640 Trumansburg NY 14886 +1 607 387 6869 johnl@iecc.com, Village Trustee and Sewer Commissioner, http://iecc.com/johnl, Finger for PGP key, f'print = 3A 5B D0 3F D9 A0 6A A4 2D AC 1E 9E A6 36 A3 47 [TELECOM Digest Editor's Note: Did you know when AT&T first started selling a new PBX about 1975 called 'Dimension' it had DISA in it and even the AT&T sales reps were unaware of the 'feature'. Furthermore, every single one had its passcode defaulted to the factory code '1234'. No one told the sales reps, so none of them told the customers who bought a Dimension, usually for the purpose of replacing their old manual cordboards. Dimension PBXs were going in all over the place and each one had a seven digit number assigned to the DISA port. Phreaks found out right away and were using those remote access ports in many cases when the system administrators were **unaware that such a feature was even available and installed on their system**. Whoopee! Most were big enough accounts that reconciling the monthly phone bill took the better part of a month; most had monthly bills from Illinois Bell in the range of five to six hundred thousand dollars anyway and 'a couple thousand dollars' in fraud calls was not immediatly noticed. After Dimension had been on the street for about six months, the manure started hitting the wind stream ... as telecom admins were discovering fraud up the kazooey. Calls to their AT&T account representatives did no good; the reps did not know what they were talking about, at least at first. One victim in Chicago was the Chicago and Northwestern Railroad which got hit for about four hundred thousand in fraud over three months. Illinois Bell security guys were chasing all over the midwestern United States looking for phreaks and they finally wound up writing it off. It turns out a smart employee had been cruising around the switch area one day and filched a couple of manuals which he photocopied for other phreaks. If you have a DISA port or otherwise a way of accessing your dial tone, be very, very careful, and keep a close audit trail. PAT] ------------------------------ From: Peter_Simpson@3com.com Date: Fri, 17 Oct 1997 06:17:36 -0400 Subject: Re: New Cellular Phone Experience So Far In article , Lisa Hancock wrote: > 6) Be careful charging/recharging. NiCad batteries the phone uses can > develop a memory if not fully discharged then fully charged. They > suggested I leave the phone on to run down, then fully recharge it. > That makes sense to me, although it is a pain since it does require > some advance planning to allow one day to run down and one night to > recharge. And then Brett Frankenberger wrote: > This is a very common, and very unsubstantiated, urban legend. Under > carefully controlled laboratory conditions, where you repeatedly > partially dischange the cells to the *same level* each time, you can > sometimes get a memory effect to appear, after a lot of cycles. Under > normal random usage, in which you never fully discharge the batteries, > but always discharge to a different level, the memory effect does not > appear. (Also, most newer phones won't fully discharge the cells, > prefering instead to shut themselves off when the voltage drops below > a certain level.) The truth is somewhere between the above two statements. Memory is not, as Brett points out, the problem. Instead, the problem is growth of conductive "whiskers" that, over time, connect the positive and negative plates of the NiCd cell, shorting it and reducing its output voltage to zero. Whisker growth seems to be encouraged by light usage patterns. Discharging the unit completely before fully recharging (but not over charging) lengthens the time before whisker growth becomes a problem. That's what those "battery conditioners" do. Lisa's supplier gave her the right procedure, but attached the wrong name to the problem. I'm the proud owner of several NiCd powered pieces of equipment and I am acutely aware of whisker growth. A web search will probably find several detailed articles on the phenomenon. I have been able to replace the NiCds in some of my gear with rechargeable alkalines (Ray-o-Vac "Renewal" brand) and have been very satisfied with the performance. Regards, Peter, KA1AXY ------------------------------ From: Bill_Walker@qualcomm.com (Bill Walker) Subject: Re: New Cellular Phone Experience So Far Date: Fri, 17 Oct 1997 15:15:11 -0700 Organization: QUALCOMM, Inc. In article , jra@scfn.thpl.lib.fl.us (Jay R. Ashworth) wrote: > Poor AMA on the part of your carrier. _My_ frustration is that the > timer on my _digital_ CDMA phone from Qualcomm by way of PrimeCo > _could_ give me actual time ... they just didn't _bother_ to engineer > the system correctly. Well, I guess you could call it bad "system level engineering", but we couldn't reengineer the business methods of the cellular carriers. Billing in U.S. cellular systems (and PCS systems, which follow the cellular model) is typically done offline by a system that reads a tape (or other media) containing Call Detail Records generated by the cellular system. This means that the cellular system has no knowledge of: 1) At what point in the call the carrier starts billing (depending on how much call setup information is reported in the Call Detail Records). 2) At what point in the call the carrier stops billing (ditto. Is it when the air interface is released, or when the PSTN side of the call is released?) 3) what rates the carrier may be charging. Now, _if_ the cellular infrastructure were expected to have that information, then I'd agree that it was a failing of system design for us to not have provided a way for the infrastructure to convey that information to the phone. Bill Walker, QUALCOMM, Inc., San Diego, CA USA Bill_Walker@qualcomm.com Support the anti-spam amendment. Join at ------------------------------ End of TELECOM Digest V17 #285 ******************************