29 Years of the Digest ... founded August 21, 1981
The Telecom Digest for June 08, 2011
====== 29 years of TELECOM Digest -- Founded August 21, 1981 ======
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Date: Mon, 06 Jun 2011 07:31:15 -0700 From: Sam Spade <firstname.lastname@example.org> To: email@example.com. Subject: Re: Busy trunks--subscriber behavior Message-ID: <9OydnSuFnqMpeXHQnZ2dnUVZ_sednZ2d@giganews.com> Wes Leatherock wrote: >>If a lot of subscribers remained off-hook, no harm, no foul, unlike >>a No 5 XBAR, which could crash given sufficient permanent off-hooks. >> [...] >>The No. 1 and 1A would eventually dump the permanent off-hook to the >>receiver off-hook (ROC) routine, then to suspend status ("dirty" >>battery). If traffic were really busy, the ROC tone would not be >>provided. >> >>Nonetheless, the switch would be more apt to eventually provide dial >>tone to a subscriber who remained off-hook (that is, until ROC >>kicked-in) as opposed to a subscriber who would repeatedly plunge >>the switch-hook. >> >>No doubt the No 5ESS would handlle the situation much the same >>because of similar design policies for such matters. If the subscriber remains off-hook waiting for dial tone in a very busy condition I don't believe the ROH routine would come into play until after dial tone were provided and not acted upon in the prescribed time. As to the No 1/1A dropping to dirty battery after completion of the ROH routine, the continuous popping sounds you then heard were sounds of orders (machine instructions) being issued by the processor.
Date: Mon, 06 Jun 2011 07:33:57 -0700 From: Sam Spade <firstname.lastname@example.org> To: email@example.com. Subject: Re: There's no easy escape from cellphone risks Message-ID: <D5-dnS1cc-zIeHHQnZ2dnUVZ_q2dnZ2d@giganews.com> Wes Leatherock wrote: > > Several commentators in the U.S.A. have noted that the possible danger > is about the same as the WHO cites for drinking coffee. > > > Wes Leatherock > firstname.lastname@example.org > email@example.com > Everyone at Starbooks is using their cell phones while drinking their coffee. We need a study for that reckless behavior. :-)
Date: Mon, 6 Jun 2011 23:25:09 -0400 From: Monty Solomon <firstname.lastname@example.org> To: email@example.com. Subject: SecurIDs Come Under Siege / Security Breach Forces RSA to Offer to Replace Millions of 'Tokens' Message-ID: <firstname.lastname@example.org> SecurIDs Come Under Siege Security Breach Forces RSA to Offer to Replace Millions of 'Tokens' By SIOBHAN GORMAN And SHARA TIBKEN JUNE 7, 2011 RSA Security is offering to provide security monitoring or replace its well-known SecurID tokens-devices used by millions of corporate workers to securely log on to their computers-"for virtually every customer we have," the company's Chairman Art Coviello said in an interview. In a letter to customers Monday, the EMC Corp. unit openly acknowledged for the first time that intruders had breached its security systems at defense contractor Lockheed Martin Corp. using data stolen from RSA. SecurID tokens have become a fixture of office life at thousands of corporations, used when employees log onto computers or sensitive software systems. The token is an essential piece of security, acting as an ever-changing password that flashes a series of six digits that should be virtually impossible to duplicate. ... http://online.wsj.com/article/SB10001424052702304906004576369990616694366.html
Date: Tue, 7 Jun 2011 00:13:37 -0400 From: Monty Solomon <email@example.com> To: firstname.lastname@example.org. Subject: Projects Use Phone Data to Track Public Services Message-ID: <email@example.com> Projects Use Phone Data to Track Public Services By JOSHUA BRUSTEIN June 5, 2011 When New Yorkers head underground, they cannot always be sure of what awaits them. The city's subway system can be mysterious, with daily delays resulting from minor emergencies, track work and other events in the tunnels that riders know they will never truly understand. The city's Metropolitan Transportation Authority has been trying to provide a better sense of predictability in recent years by adding displays in stations that state when the next train is expected. Now, a Web development firm called Densebrain says that it can do the same thing at practically no cost, by analyzing how people lose phone service when they head underground. Urban planners, technology companies and officials from local governments see potential in projects like these that mine data collected from phones to provide better public services. Boston is developing a system called Street Bump that uses a smartphone's accelerometer and GPS system to detect when a driver hits a pothole and then sends that information to city officials. Techniques like this may help cities collect data that until recently would have required expensive network sensors. ... http://www.nytimes.com/2011/06/06/business/media/06transit.html
Date: Mon, 06 Jun 2011 09:17:38 -0400 From: "Pete Cresswell" <x@y.Invalid.telecom-digest.org> To: firstname.lastname@example.org. Subject: Re: Caller Pays vs. Called Party Pays (was Re: DSL Reports: AT&T Caps Have Arrived) Message-ID: <email@example.com> Per Stephen: >- it make free call, geographic independent numbers and low cost call >services more common here. - It would mean the end of the spam/telephone solicitor calls that my cell phone has been getting more and more of as the bottom feeders move offshore and hide behind VOIP providers. -- PeteCresswell
Date: Mon, 6 Jun 2011 16:16:25 +0000 From: Arthur Shapiro <firstname.lastname@example.org> To: email@example.com. Subject: Plumbers and other artisans Message-ID: <firstname.lastname@example.org> >***** Moderator's Note ***** > >...I didn't make that much when I was a surgeon!" > >Bill Horne, who's father was a plumber Straying off topic, but you'll have to chuckle: I once had my plumber in the middle of a cashectomy at my home, and overheard him on a cellular phone call to his auto mechanic. Apparently he needed major engine work performed on the plumbing van. "HOW MUCH?!!!", etc., etc. I imagine there's some sort of pyramid in the skilled trades; I wonder who's the top banana. Art ***** Moderator's Note ***** I've made this into a separate thread. Bill Horne Moderator
Date: Mon, 6 Jun 2011 07:14:17 -0700 (PDT) From: Lisa or Jeff <email@example.com> To: firstname.lastname@example.org. Subject: Re: Busy trunks--subscriber behavior Message-ID: <email@example.com> On Jun 6, 6:17 am, Sam Spade <s...@coldmail.com> wrote: > > Other BSTJ articles discussed what happens to subscribers if there are > > too many off-hook (people trying to make calls) all at once. > > Obviously this was something they had to provide for very early on as > > emergency situations (eg major storms) would spark such calling. > > Later, radio promotions and the like could do so. One issue was > > whether a subscriber had "a place in line" while waiting, that is, > > were they served in turn, or randomly picked when a receiver became > > available. The BSTJ also gives rather complex statistical analysis > > formulas on all of this (as well of course trunk group usage and > > blocking). > > I don't know the technical reasons but I do know that 65 permanent ROHs > would crash a No. 5 XBAR. That was one of the reasons for 24/7 > maintenance staff to pickel those ROHes, thus rendering them harmless.- ROH = 'receiver off hook' ? I'm surprised ROH could do that kind of damage. People taking their phone off the hook to not get called, or, people leaving thier phone off accidently are both extremely common. In addition,a short circuit in a loop line may cause an off-hook. Is this ROH situation described in the literature anywhere? According to the literature, ROH was forseen as an issue back in panel development, and timers were included to cut out the subscriber after a time interval has passed. This timer also applied while dialing. Timers continued in crossbar, and also included internally as call functions were pased from one unit to another--if the next unit didn't pick up in time, alternative action was taken. The switch had redundancy built into it. Being a high complex electro-mechanical device often serving many thousands of subscribers there was a risk of failure. If a key component failed the switch could work around it but obviously traffic capacity would be reduced and dial tone might be delayed. Accordingly, a large switch may get 24/7 staffing, although some of that may be to take advantage of light traffic to do maintenance. Certainly a high volume of traffic, either from subscribers or inter- exchange trunks, would slow processing. But the literature in BSTJ suggests the switch would not "crash"--that is totally shut down--but rather just be slow in handling calls. It might work less efficiently as components spend more time than normal trying to find alternate paths over busy components or busy trunks, but eventually a call would go through. Perhaps I am splitting hairs on the difference between "no service at all" and "very slow service", but to me there is a big difference between a "system crash" where everything has failed and a restart is necessary, and a "systems slowdown" that is a temporary problem.
TELECOM Digest is an electronic journal devoted mostly to telecom- munications topics. It is circulated anywhere there is email, in addition to Usenet, where it appears as the moderated newsgroup 'comp.dcom.telecom'. TELECOM Digest is a not-for-profit, mostly non-commercial educational service offered to the Internet by Bill Horne. All the contents of the Digest are compilation-copyrighted. You may reprint articles in some other media on an occasional basis, but please attribute my work and that of the original author. The Telecom Digest is moderated by Bill Horne.
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