From editor@telecom-digest.org Mon Mar 29 23:18:22 2004 Received: (from ptownson@localhost) by massis.lcs.mit.edu (8.11.6p2/8.11.3) id i2U4IM623947; Mon, 29 Mar 2004 23:18:22 -0500 (EST) Date: Mon, 29 Mar 2004 23:18:22 -0500 (EST) From: editor@telecom-digest.org Message-Id: <200403300418.i2U4IM623947@massis.lcs.mit.edu> X-Authentication-Warning: massis.lcs.mit.edu: ptownson set sender to editor@telecom-digest.org using -f To: ptownson Approved: patsnewlist Subject: TELECOM Digest V23 #149 TELECOM Digest Mon, 29 Mar 2004 23:18:00 EST Volume 23 : Issue 149 Inside This Issue: Editor: Patrick A. Townson Emerging VOIP Companies to Get Financial Assistance (VOIP News) DSP Filter Setup on LineJack/PhoneJack Card? (Mark) Easy to Use Intercom Systems (Dr. Joel M. Hoffman) Nuisance Recorded Phone Calls (TELECOM Digest Editor) Re: Western Union Clocks (S Falke) Re: Western Union Clocks (J Kelly) Re: Verizon Execs Get 911 Carpet Call (Nick Landsberg) Re: A Better Way To Squelch Spam? (Fred Goldstein) The High Volume of Press Releases on VOIP Today (VOIP News) Re: Sorry, no ala Carte Cable (Jack Hamilton) All contents here are copyrighted by Patrick Townson and the individual writers/correspondents. Articles may be used in other journals or newsgroups, provided the writer's name and the Digest are included in the fair use quote. By using -any name or email address- included herein for -any- reason other than responding to an article herein, you agree to pay a hundred dollars to the recipients of the email. =========================== Addresses herein are not to be added to any mailing list, nor to be sold or given away without explicit written consent. Chain letters, viruses, porn, spam, and miscellaneous junk are definitely unwelcome. We must fight spam for the same reason we fight crime: not because we are naive enough to believe that we will ever stamp it out, but because we do not want the kind of world that results when no one stands against crime. Geoffrey Welsh =========================== See the bottom of this issue for subscription and archive details and the name of our lawyer; other stuff of interest. ---------------------------------------------------------------------- From: VOIP News Date: Mon, 29 Mar 2004 21:17:02 -0500 Subject: Emerging VOIP Companies to Get Financial Assistance from Reply-To: VoIPnews@yahoogroups.com http://home.businesswire.com/portal/site/google/index.jsp?ndmViewId=news_view&newsId=20040329005254&newsLang=en Emerging VOIP Companies to Get Financial Assistance from Industry Veterans; Peer 1 Network and Pulver.com Launch VOIP Acceleration Project VANCOUVER, British Columbia & MELVILLE, N.Y.--(BUSINESS WIRE)--March 29, 2004--Two innovators in the Voice Over IP industry joined forces today to provide assistance to start-up companies in their industry. The result is the VOIP Acceleration Project -- a joint venture in which Peer 1 Network (TSX VENTURE:PIX) and Pulver.com subsidize new VOIP companies in their bandwidth and co-location needs. "To be successful, VOIP companies need reliable high-quality bandwidth and secure servers to ensure that their product or service is always available. Their consumers demand it," says Geoff Hampson, President & CEO of Peer 1 Network. "Peer 1's nation-wide backbone and fully redundant data centres guarantee this high level of performance." Peer 1's world-class Internet network is complemented by Pulver.com's knowledge of the industry. Together, the companies can provide a launching pad for VOIP entrepreneurs with the vision, but not necessarily the financial backing, to take VOIP to the masses. "The world is embracing VOIP," says Jeff Pulver, founder of Pulver.com, "and we are at the forefront of that movement. By identifying and nurturing some key start-ups, we aim to revolutionize the way the world communicates." For more information about the VOIP Acceleration Project, please visit the Web site at www.pulver.com/colo. Contacts Pulver.com Jeff Pulver, 631-961-8951 jeff@pulver.com www.pulver.com or Peer 1 Network, Inc. Katie Wilson, 604-683-7741 kwilson@peer1.net or Geoff Hampson, 604-683-7741 ghampson@peer1.net www.peer1.net ------------------------------ From: jjohnson@cs.ucf.edu (Mark) Subject: DSP Filter Setup on LineJack/PhoneJack Card? Date: 29 Mar 2004 16:32:17 -0800 Organization: http://groups.google.com Can anyone tell me how the DSP filter parameters (for call progress tone detection) are set in Quicknet's LineJack/PhoneJack (VoIP card) Linux drivers? I want to enter some new filter coefficients for detecting other tones, and need more info about how the DSP implements its filters. Overview follows the questions below: QUESTIONS: 1) Are these coeffs for an IIR filter? 2) Do the coeffs correspond to the difference equation (order and assoc): y(n) = B0*x(n) + B1*x(n-1) + B2*x(n-2) - A1*y(n-1) - A2*y(n-2) ? (Do I have the A's & B's and index numbers mixed up? I don't see the expected frequency response when I run these filters.) 3) How are they selecting and computing the in-band energy threshold and in-band to broad-band ratio? Are they running an FFT or broadband filter every frame to get the broadband energy? 4) Why do they pass 3 separate groups of coefficients? How are they used in a call to the filter? Are they all used simultaneously? Or does the DSP just use one set, based on some other condition? 5) How is the overall scaling determined for the filter? Bit weights (in converting the floating-point coeffs to integer) appear to be scaled by either +/-16384 or +/-32768, but not exactly in some cases, and they differ by groups... Any help is much appreciated; many thanks in advance... MarkJ OVERVIEW: They initialize a tone table with the freq(s) they want to detect, thresholds, etc ... and then pass them as a struct to the DSP. The struct contains 19 words: COEFF GROUP 1 (A1, A2, B2, B1, B0) COEFF GROUP 2 (A1, A2, B2, B1, B0) COEFF GROUP 3 (A1, A2, B2, B1, B0) Internal filter scaling Minimum in-band energy threshold 21/32 in-band to broad-band ratio 0x0FF5 /* shift-mask 0x0FF (look at 16 half-frames) bit count = 5 */ As an example of one entry in the tone table: static s16 tone_table[][19] = { { /* f20_50[] 11, detect energy between 20Hz and 50Hz */ /* COEFF GROUP 1 */ 32538, /* A1 = 1.985962 */ -32325, /* A2 = -0.986511 */ -343, /* B2 = -0.010493 */ 0, /* B1 = 0 */ 343, /* B0 = 0.010493 */ /* COEFF GROUP 2 */ 32619, /* A1 = 1.990906 */ -32520, /* A2 = -0.992462 */ 19179, /* B2 = 0.585327 */ -19178, /* B1 = -1.170593 */ 19179, /* B0 = 0.585327 */ /* COEFF GROUP 3 */ 32723, /* A1 = 1.997314 */ -32686, /* A2 = -0.997528 */ 9973, /* B2 = 0.304352 */ -9955, /* B1 = -0.607605 */ 9973, /* B0 = 0.304352 */ /* Scaling & detection parameters? */ 7, /* Internal filter scaling */ 159, /* Minimum in-band energy threshold */ 21, /* 21/32 in-band to broad-band ratio */ 0x0FF5 /* shift-mask 0x0FF (look at 16 half-frames) bit count = 5 */ }, etc... ------------------------------ Date: Tue, 30 Mar 2004 01:42:19 +0000 (GMT) From: joel@exc.com (Dr. Joel M. Hoffman) Subject: Easy to Use Intercom Systems Organization: Excelsior Computer Services My sister is intermittently disabled, and when she needs help, she's often confused. So I'm looking for a (wireless, probably) home intercom system that can page all the remote stations with one botton. Additionally, a baby-monitor feature would be nice, along with the usual station-to-station and broadcast features. I know nothing about intercoms. Can we do this wirelessly? Should we plan on wiring a house? Can the intercoms run over spare phone line? Can someone recommend a good model? Many thanks. -Joel [TELECOM Digest Editor's Note: You can run them over a spare phone line in many cases, but the easiest to use are the 'wireless' ones. You plug them in a power outlet and they talk to each other over the AC electric line. They will, in theory, talk to any other instrument of their kind on the same 'leg' of the power transformer. Depending on the size of your house, of course, three or four such units plugged into the wall socket in various rooms *should* work okay. I do not think the audio quality is all that good, but they may do what you want sort of inexpensively. PAT] ------------------------------ Date: Mon, 29 Mar 2004 21:14:35 EST From: TELECOM Digest Editor Subject: Nuisance Recorded Phone Calls I have lately been getting one or two calls daily from a recorded message which identifies itself as 'customer service' and claims to have an important matter to discuss with me. I am to call back to 'customer service' at 877-706-5624. For several days, I just ignored it, treated it as a nuisance to petty too complain about very much. I found is impossible to block the number from calling me. I was not even able to track down *who* owned the number. But I found something of value today and it may be useful for you as well. The 'Resporg' (or Responsible Organization) Identification Line can tell you which telco has the line in question. Dial 800-337-4194 (recorded menu) and enter the entire ten digit number (800,888,877, 866-xxx-xxxx) you are inquiring about. Confirm your entry when requested. The recording will then read out the name of the resporg and the number to call for troubles with it. I found out that my nuisance calls were originating via Allnet, in Dallas, TX and the number to call to report troubles, etc is 800-466-4600. I hope this detail will be of value to readers. PAT ------------------------------ From: S Falke Subject: Re: Western Union Clocks Organization: SBC http://yahoo.sbc.com Date: Mon, 29 Mar 2004 23:39:39 GMT Alan Burkitt-Gray wrote in message news:telecom23.147.2@telecom-digest.org: > I don't know how it happens in North America, where you use 525 > lines/60 Hz/NTSC, but in Europe -- the land of 626 lines/50 Hz/PAL -- > machines use the teletext signals, a 30+ year old text-based > information system which uses spare lines in the vertical blanking > interval. Teletext is used for news, weather, sports results, TV > listings, and so on. Teletext? Gnarley! I remember about 30 years ago when Wireless World magazine used to promote Teletext as the Next Big Thing what turned out to be a true precursor to the World Wide Web. --s falke ------------------------------ From: J Kelly Subject: Re: Western Union Clocks Date: Mon, 29 Mar 2004 19:13:47 -0600 Organization: http://extra.newsguy.com Reply-To: jkelly@newsguy.com On Thu, 25 Mar 2004 19:59:41 -0800, Al Gillis wrote: > So who can explain this about time: Most modern DVD/VCR machines can > set the time based on signals from a TV station, most frequently a > public broadcasting stations (CPB?) So how does that work? And why > does it take so long to set the time? I'd guess there is some sort of > signal during the vertical retrace interval or something like that but > I've not been able to find any authorative referances to this feature. > Explain it, please!! Participating PBS stations transmit the time signal on Line 21 of the Vertical Blanking Interval. My Sony VCR sets itself withing about 5 minutes. I doesn't make the DST changes until I cycle the power for some reason. ------------------------------ From: Nick Landsberg Reply-To: hukolau@NOSPAM.att.net Subject: Re: Verizon Execs Get 911 Carpet Call Date: Mon, 29 Mar 2004 23:31:10 GMT Organization: AT&T Worldnet VOIP wrote: > More: Apparently Verizon admits that it was their fault -- > "Technicians were making changes to reroute calls that night. One > technician made a bad data entry that caused calls to be diverted away > from an emergency center." Historical data from high-reliability systems has shown that only 20% of the failures are because of hardware faults. 40% come from software faults and another 40% are because of operator error. One could argue that the "system" should have prevented the operator error, but (see signature line). Then again, it could have been that there was a one character typo which still pointed to a perfectly legitimate network address. Even the ubuquitous "Are you sure?" dialog on most Windoze boxes would not have prevented this since the operator would naturally just hit "yes" or return when that popped up. For those morbidly curious, I have some second-hand info about a 10 hour outage on a 5ESS switch in Virginia during the early 90's which was caused by a single character typo (and a bunch of cascading errors after that.). "It is impossible to make anything foolproof because fools are so ingenious" - A. Bloch ------------------------------ Date: Mon, 29 Mar 2004 19:52:35 -0500 From: Fred Goldstein Subject: Re: A Better Way To Squelch Spam? On Mon, 29 Mar 2004, Tom Betz didst uttereth, >> http://www.technologyreview.com/articles/wo_johansson032604.asp > The same old 'hashcash' proposal, which penalizes everyone to try to > stop spammers; and of course, when the spammer is abusing a hijacked > Windows PC to send spam, which is the typical case these days, it > doesn't penalize the spammer at all. Indeed. The article says, > Money stamps raise other significant issues: Who redeems the stamp? Who > has taxing authority on the income? Who bears legal liability for > erroneous or absent stamp validation? Who controls access to your mailbox > and for how big a stamp? These questions make it clear why we and many > others distrust money stamps as a solution to spam. Well, there are obvious solutions to that problem. "Work stamps", like hashcash, just lead spammers to steal cycles, which, Moore's Law noted, keep getting cheaper. Money, though, is money. Here's a way to do it. Let anybody issue money stamps. Let the issuer keep the money. Let them use the money to build the necessary server infrastructure, and if it's profitable, fine. A "stampette" is, in effect, a one-time certificate, and the issuer is a certificate authority whose certificates can't be cached. I'm estimating a price of few thousand stampettes per dollar. The stamps would only be needed for mail from strangers. A user could create a whitelist of users whose mail would not require a stampette. Mailing lists would require their subscribers to whitelist them. Or maybe a permanent certificate (vs. a one-time stampette) would be used for mailing lists, to prevent spoofing. You wouldn't want a spammer to get around it by claiming to be telecom-digest, would you? Now the reason this works is that the recipient does not automatically accept anything passing itself off as a stampette. The recipient only accepts stampettes that are validated by an issuer that it knows and trusts (whitelists). If an issuer charges too little, its stamps may become attractive to spammers, but that will lead recipients to remove them from their whitelists, putting the issuer out of business. (An end user might have the ability to control their own whitelist, but more typically an ISP would pay attention.) If an issuer charges too much, nobody will buy its stamps. Very self-correcting. Very "Adam Smith", free market, decentralized, scalable, end to end, yadda yadda. Naturally, a lot of "mail must be FREE as in BEER" purists oppose this, and it has some potential issues, but I don't see how any cashless system can ever stay ahead of the spammers. More at http://www.ionary.com/ion-spam.html . ------------------------------ From: VOIP News Date: Mon, 29 Mar 2004 21:35:46 -0500 Subject: Number of Press Releases Today and This Week Reply-To: VoIPnews@yahoogroups.com I should probably explain that the high number of press releases today, and probably for the next couple of days at least, are triggered by the Spring 2004 VON Conference in Santa Clara, California. As Jimmy Durante said, "Everybody wants to get into the act", and that seems to be the case with VoIP companies issuing press releases. I've read quite a few of them and have chosen not to use several, either because they seemed to have no impact on consumer IP, or they basically said things that were already reported last week, or I just plain didn't understand what they were trying to promote. Remember that this is an open (albeit moderated) list, so if you think I left out an important press release you can always send it to the list address, VoIPnews@yahoogroups.com Please make sure to include the URL for anything that you've found on the Web. For everyone else, I'm really sorry about the number of press releases and such, but hopefully it's only for another day or two. How to Distribute VoIP Throughout a Home: http://michigantelephone.mi.org/distribute.html If you live in Michigan, subscribe to the MI-Telecom group: http://groups.yahoo.com/group/MI-Telecom/ ------------------------------ From: Jack Hamilton Subject: Re: Sorry -- No a la Carte Cable Date: Mon, 29 Mar 2004 20:05:48 -0800 Organization: Copyright (c) 2004 by Jack Hamilton. Reply-To: jfh@acm.org Monty Solomon wrote: > Channel Packaging Is So Much Cheaper, Incredulous Senators Are Told > By Frank Ahrens > Washington Post Staff Writer > No U.S. cable or satellite company offers what are called "a la > carte" plans. In order to get the Discovery Channel from Comcast > Corp. cable company, for instance, Washington viewers have to pay for > an "expanded basic" package that includes MTV, FX, MSNBC and 33 other > channels. That's not entirely true. Dish Network offers an a la carte plan, but it's for "international" channels only. http://www.dishnetwork.com/content/programming/international/a_la_carte/index.shtml If Telugu is your only language, you can get Telugu programming without having to pay for 100 channels of incomprehensible English. Jack Hamilton jfh@acm.org In the end, more than they wanted freedom, they wanted comfort and security. And in the end, they lost it all - freedom, comfort and security. Edward Gibbons ------------------------------ 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 networks such as Compuserve and America On Line, Yahoo Groups, and other forums. It is also gatewayed to Usenet where it appears as the moderated newsgroup 'comp.dcom.telecom'. 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End of TELECOM Digest V23 #149 ******************************