From telecom@delta.eecs.nwu.edu Thu May 11 15:50:34 1995 1995 15:50:34 -0400 1995 12:22:31 -0500 To: telecom@eecs.nwu.edu TELECOM Digest Thu, 11 May 95 12:14:00 CDT Volume 15 : Issue 237 Inside This Issue: Editor: Patrick A. Townson Job Opening at BellSouth (Chendong Zou) Re: RBOC IP Legislation Scaring Local ISPs (Tim Gorman) Re: Use of CDPD For Redundancy in Cellular Networks (John Agosta) Re: Mexico Billing Method: Digit Analysis or Meter Pulse? (Lars Poulsen) Re: Voice/Data Multiplexer for 64kb Leased Line? (Dan Matte) Re: Calls From Australia to US 800 Not Delivering DTMF (Serge Burjak) Re: Annoying Calls: Can We Deal With Them? (Bradley Ward Allen) Re: Annoying Calls: Can We Deal With Them? (Bruce Roberts) Extending Cordless Telephone Range (Greg Smith) 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@eecs.nwu.edu * 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: 9457-D Niles Center Road Skokie, IL USA 60076 Phone: 500-677-1616 Fax: 708-329-0572 ** Article submission address only: telecom@eecs.nwu.edu ** Our archives are located at lcs.mit.edu and are available by using anonymous ftp. The archives can also be accessed using our email information service. 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Any organizations listed are for identification purposes only and messages should not be considered any official expression by the organization. ---------------------------------------------------------------------- This is posted for a friend, please use the contact info. below: ATTENTION: 1) In my previous posting on 5/9, I inadvertently forgot that our Employment Office needs to file your application. As a result, I am reposting this job specs with the correction that individual candidate should send resume to (resume@snt.bst.bls.com). 2) The Internet address is used for all groups within Science & Technology, BellSouth Telecommunications. Since there are openings in other groups, You may still want to send your resume even though your background may not match the job specs described below. 3) Search firms please do not response to this posting. A subsequent posting describes detailed qualifications and steps to submit your candidate resumes will follow. DATE: May 11, 1995 CONTACT: Send text resume to (resume@snt.bst.bls.com) and reference to Dr. Eric Kai. LOCATION: Atlanta, Georgia COMPANY: BellSouth Telecommunications, which has revenues in excess of $13 billion and assets of over $28 billion, has several R&D positions available in the Wireless Service Integration group of the Science & Technology department. Our charter is to: - provide technical support to BellSouth's business units in developing and implementing the business strategies for wireless market, - conduct technical evaluation, requirement specifications, system/software engineering, prototype/product development and technical/marketing field trials, - R&D technical solutions to offer integrated/enhanced wireless services to BellSouth consumers and/or PCS service providers within our region, - interact with vendor in product selection, requirement definition and/or joint development to support wireless products and services. EXPERIENCE/SKILL: Successful candidates should possess M.S. or Ph.D. in EE, CS, Telecommunication, or related disciplines. M.S. with a minimum of three years of experience (or equivalent) in the wireless telecommunication industry having solid working knowledge of wireless networks such as cellular, mobile data and/or PCS is required. Experience on system engineering, fast prototyping and software development on wireless product and services is highly desirable. Candidates must have expertise in at least one of the area below: RF Design Area: solid experience in frequency planning, system growth planning, cell site traffic analysis and RF propagation to conduct the design/development of a Radio Planning tool for cellular/PCS network under CDMA, GSM and TDMA. Familiar with the air interface standards. Wireless Data Area: working knowledge with wireless data technologies such as CDPD, PCS data over CDMA and GSM, and/or other mobile data applications. Network Area: knowledge of SS7, ISUP and ISDN signaling and/or transport. Good understanding of HLR/VLR/AM mobility management under cellular/PCS for CDMA, TDMA and GSM. Familiar with IS-41/GSM MAP. R&D experience in the transparency of integrated wireline and wireless services using AIN capabilities and other intelligent network features. OAM&P Area: experience in numbering plan, CDR/AMA, cellular rate plan, billing services and downstream data processing and management. Working background in designing/developing OSS such as PCS/cellular network management, PCS performance tuning and traffic analysis, customer trouble tracking, etc. PERSONAL: This individual must have: - good interpersonal skills to work in a highly competent technical team. - motivation to understand the business needs of BellSouth and to find effective matches between these needs and emerging technologies, - ability to work in an effective, cooperative manner with other client organizations within BellSouth as well as external companies. OTHERS: - Search Firm please do not response to this job post. A subsequent post will describe detail steps for you to send your candidate resumes. Chendong Zou Internet: zou@ccs.neu.edu College of Computer Science, Northeastern University 360 Huntington Avenue #23CN, Boston, MA 02115 Phone: (617) 373 3822 WWW: http://www.ccs.neu.edu/home/zou Fax: (617) 373 5121 ------------------------------ fratkins@freenet.columbus.oh.us (Frank Atkinson) writes in TELECOM Digest V15 #233: > Without going too deeply into the regulatory system that built the > network which took what the company spent, added a guaranteed rate of > return, and in some cases hidden taxes, then passed it on to the rate > payer's bill (rate of return regulation). The shareholder's position > has been fairly well protected. Maybe each ratepayer should be given > some company stock now that the network they built will be used to > compete. The company hasn't sold enough stock to fund the network, the > money came from the ratepayers, the ratepayers repaid the consturction > bonds, not the stockholders. If each ratepayer should be given stock in the telephone company then why shouldn't each Ford owner be given stock in Ford? The car owners repaid the debt issues (including debt bonds) of Ford, not the stockholders. This is true of ANY company. The stockholders of Ford certainly didn't repay the debt issues of Ford in order to provide free cars to consumers. The problem with this logic is that: 1. The stockholders in the telephone companies did NOT make a killing. The dividends were always very low compared to other companies of similar revenues. The difference was that much of the company income flow DID go to pay off debt issues as well as being reinvested. The stockholders PAID a penalty for low risk by also incurring low yield. 2. The telephone companies were NEVER guaranteed a rate of return. In fact, the commissions set MAXIMUM rates of returns, not minimums. If rate relief was requested by the telco during a rate hearing it was incumbent upon the phone company to show that the rate of return during a measurement period prior to the hearing was insufficient to operate the company and attract sufficient capital. There were lots of years that the commission set MAXIMUM rate of return was never approached. By the same token, having a MAXIMUM rate of return limit did not provide much incentive for modern- ization, for creative service offerings, or for innovation. These are things driven by competition. 3. There is NOTHING wrong with reinvested earnings. Funding a capital intensive operation does NOT have to be done totally by shareholder investment in order to be "acceptable" Once again, we see a view that somehow transforms the phone company into being a non-profit, psuedo-government type of operation that should be "owned" by all citizens since it was paid for by "psuedo- taxes" on the ratepayers masking as "rates" for services. The assets owned by the shareholders should just be given away thus diminishing the value of each share held by the shareholders. They just got rich by trampling the "rights" of the ratepayers so who cares? Folks, the phone companies have always been just that -- COMPANIES. They have always been companies owned by shareholders -- just like Ford, Pizza Hut, and Midas Muffler. Just like any other company, these shareholders expected the company to make a profit and pay a dividend. The amount of the dividend versus the investment was never near the top but it was constant -- which is why AT&T stock used to be known as the stock for little old ladies looking for a guaranteed income. Since the telco's were franchised monopolies they were regulated. There was always two sides to the regulation: 1. See that the ratepayer received the proper value for the rates being paid. 2. Allow the company to earn adequately to provide the required service. You may want to argue all day long on how good of a job the various Public Utility Commissions did of regulation. You may even want to argue whether having regulated monopolies did or did not do the best for the consumer in the long run. But it is not valid to argue that the telco's, companies OWNED by private citizens, should somehow be nationalized. Those shareholders deserve an adequate rate of return on their investment, just as the shareholders of MCI, Sprint, and J.C. Penny deserve an adequate rate of return on their investment. Tim Gorman tg6124@tyrell.net Southwestern Bell Tel. Co (I speak only for myself) ------------------------------ rothen+@pitt.edu (Seth B Rothenberg) writes: > I recently did some work investigating CDPD. One observation I made > was that CDPD is an excellent way to gain redundancy. In most areas > (most populated areas?), there are two cellular carriers. Since the > last mile is what is at greatest risk, half of any circuit is > protected 100%. I'm not sure what you mean about 1/2 of each circuit ... but, not understanding your situation entirely, I'll put in my two cents ... > My question is about the other half. Does anyone know if there is an > easy way to, for example, have a router connection to both the A-side > carrier and to the B-side carrier? Then, you'd have almost perfect > reduncancy. Each carrier is considered its own domain, with different IP net assignments / hosts etc. In order to use both carriers, an account would have to be established and IP addresses assigned to the M-ES for each carier. On the land line side, you would need a connection to your fixed end system from each carrier, meaning your router would need two ports, one connected to each CDPD provider. Your M-ES would need to be programmed with two IP addresses. (Many M-ESs can handle more than one, CMI does ten for instance.) Another way to work would be to use a single IP address, however, inter-working agreements between the A and B carriers would have to be in place, physical connectivity between the carriers would have to be in place, and roaming charges (or similar) may apply. (much deleted) > What I am not clear about is, where the IP address is > looked up. Does the CDPD Mobile End Station know its own IP address? > I would think it WOULD NOT need to know it, because the Data Service > Manager would do that. The CDPD mobile device does know its IP address, as per above. The IP address "lookup" is done at a database in the carrier user signs up with. The database is located in a "Home" function. All authentication, etc is done at this "home" function, regardless as to where the mobile user actually is being "served" from. If I lived in Chicago, for instance, my "home" function would be in Chicago (or the closest one to my office if there was more than one). > If this is the case, the device would just have two IP addresses, one > on each network. My company's routers would need to be configured to > route via whichever path is available. One IP address is required if only one "home" needs to be consulted for authentication purposes. Hence, interworking must be done between carriers A and B if one database is to serve the user. One router connection would be required as well in this scenario. If two network "accounts" are being used, yes, you would need two IP addresses. Did this help? I hope so. If you email me, we can have a more detailed discussion. John ------------------------------ In comp.dcom.telecom is written: >> Does Mexico / Central America use a digit analysis method for >> calculating charges, or a metered pulse method? What I'm actually >> refering to is the SMDR output on a PBX. I believe the U.S. is in the >> minority in using digit analysis, or am I wrong? In article Jan Hinnerk Haul writes: JHH> [for chargeback cost analysis] quite a lot of PBXes can do number JHH> analysis as an alternative method [to reading billing pulses]. JHH> The drawback of number analysis is, of course, that no call JHH> supervision is possible, letting users being "billed" with uncompleted JHH> calls if they wait longer than the set timeout period and letting very JHH> brief calls unbilled. This is an oversimplification. Even without billing pulses, you are not always limited to a simple timeout in determining whether the call was answered. The real answer -- as usual -- is "it depends". In some areas of the world [including specifically Denmark; I don't have any experience with Hispanic America], you will in fact be billed at the rate of the dialed number, even if the call was never answered. The logic is that you have been tying up facilities along the call path, just as if the call had been connected. Whether you get charged for uncompleted calls is of course an administrative tariffing issue, although it may depend on whether the switch is equipped to detect whether the call was connected. (In some areas, where trunking is analog, the information may not be available to the switch.) Independently of whether you get charged for the uncompleted calls, you may have either a short loop disconnect or a polarity reversal when the call is connected. This depends on the specific switching equipment that the line is connected to. Typically, the short disconnect is seen on older mechanical switches, while the option to provide a polarity reversal is available on newer switches. Most administrations can provide a booklet defining the subscriber interface, and saying that "you may see ..." this or that feature and any equipment connected must be able to deal with all of these. But unless you have a technical contact in the repair bureau, you will probably not be able to find out: - what switch type is serving a specific line - what options are available for that line on that switch, or ·_ - how the specific line is actually configured. Lars Poulsen Internet E-mail: lars@RNS.COM Rockwell Network Systems Phone: +1-805-562-3158 7402 Hollister Avenue Telefax: +1-805-968-8256 Santa Barbara, CA 93105 Internets: designed and built while you wait ------------------------------ In , harlan@Physik.TU-Muenchen.DE (Magnus Harlander) writes: > We are looking for a data/voice multiplexer for a leased 64kb > digital line. We want to use some portion of the bandwidth for phone > calls to and from a PBX extension and the rest for IP traffic. The > leased line speaks the G.703 protocol (there would be an alternative > using I.430). Any information about implementations, producers and > distributors is appreciated. Memotec Communications Inc (Canada/US) also provides a solution for this application that accomodates up to T1 speeds. CX1000 Multimedia Multiplexer 6/16 slot chassis Modules available: - Voice/Fax Compression - Data Compression - Ethernet & Token Ring bridging & routing - Frame Relay - Packet Switching - 56K DSU/CSU - FT1/T1 DSU/CSU US HQ (508) 681-0600 Canadian HQ (514) 738-4781 Dan Matte Memotec Communications Inc Vancouver, British Columbia d._matte@mindlink.bc.ca ------------------------------ TestMark Laboratories <0006718446@mcimail.com> wrote: > Serge Burjak writes in TELECOM Digest Volume 15 Issue 226: >> I have a problem getting through to some automated attendants using >> DTMF from Australia. As the title says, after the connection the line >> appears not to pass DTMF tones ie., "press 1 for this service, press 2 >> for that service." >> This happens with both Telecom and OPTUS. The customer service droids >> will not escalate the problem to anyone at an 'Engineer' level, but >> only to techs who make comments like, well "the US is probably >> translating these into something different, sorry cannot help you". >> Am I being unreasonable asking to pass in voice band information? I >> know it's not my phone, I can use Cyberlinks dial back for this or >> AT&T's USA direct with a credit card. The Cyberlink solution is not >> totally satisfactory for other resaons. The attendant requires a # key >> after the some transactions and Cyberlinks interprets this as a new >> call request. > The DTMF receivers in automated attendants are usually not up to the > same quality as a Central Office DTMF receiver. It sounds as if there > is more loss on the Telecom and OPTUS connections than there is on the > AT&T USA direct. This surprises me, as I would assume that all are > using digital transmission systems, which are "lossless!" ... lots of good stuff archived. Thanks for the reply. I am hot on the trail of the problem. After much screaming I got an OPTUS network engineer and SHE took me seriously. They did some serious testing and it turns out, OPTUS and Telecom Australia use the same LD carrier in the US to route the calls. It appears when the remote answers, the LD invloved (one of the big three) does not get an acknowledgement from this number to start billing and enable the forward voice channel. It could be related to a fraud prevention program, or more likely a poor implementation. It's still broke on this one number that I NEED to use and I have found a couple of others. Most other 800s appear to work. Stay tuned. ------------------------------ key) In article , Benjamin P. Carter wrote: > The PUC had ruled that an unlisted number would not be disclosed > unless the caller chose to disclose it. That's all. Pac Bell > asserted that too few customers would order caller ID under that rule > to make it profitable. And now the FCC has decreed that the calling > number will be disclosed unless the caller specifically choses to > block it. This makes a difference because many (perhaps most) > residential customers will ignore the whole issue of caller ID, doing > nothing to either allow or block the display of their numbers when > they make phone calls. By default, their numbers will be displayed > under the FCC rule. The rule goes into effect December 1, 1995. Pac > Bell is happy with this rule and will offer CNID in 1996. In retrospect, Pac Bell is right: I have CNID, and most the callers who call me don't care or aren't aware of CNID. Their numbers just show up on my box. Those who do care about CNID usually have gone out of their way to block their lines. Very few are aware and let it show, and I bet that if they had to actually call and activate the showing of their number, they wouldn't have done it. If they had to actively turn it on, my CID box would be practically useless. However, I can see putting a recording on my line, which whenever I received an Out Of Area or Private call would say: "Right now you can reach me at 1-800-BRADLEY" or whatever, then hang up. When they called back, they'd go through my WilTel or other 800 number which passes ANI via CNID ... (: I would still find this useful. I'm trying to figure out what inexpensive equipment I can get which would do this. Bradley ------------------------------ Messrs. Greenberg and Cogorno have, quite properly, taken me to task for getting the California PUC decision on caller-id wrong. It was *not* the fact that the PUC wanted per-line blocking as an option but rather that they insisted all unlisted lines be per-line blocked by by default. My thanks to these gentleman for correcting me and my apology to the participants for putting out wrong information. TTFN -br- Bruce Roberts, bruce.roberts@greatesc.com ------------------------------ I recently installed a cordless telephone (Partner Plus - AT&T CDM 9000) for a client. The cordless gets great range when I locate the base/charger near the outside wall of the building. However, the owner wants his base/charger located in his office in the middle of the office building which severly limits his range and clarity when he uses his cordless outside. Is it possible to install an external antenna on the outside of the building to improve the signal from the cordless base/charger? Thanks, Greg smithgl@ndlc.occ.uky.edu [TELECOM Digest Editor's Note: You can do this, but a couple problems come to mind. You are not dealing with that much signal strength to begin with, and some dissipation will occur in the coax between the base unit and the rooftop antenna, which, IMO, will get you back to about where you started, range-wise. It is also possible to open up the base unit and 'peak' it up some if you know how to trim those pots a little that you find inside. Know what you are doing please, before you take a screwdriver to the inside of any radio transceiver. Most cordless phones have how much power ... about a hundred milliwatts? So maybe you get in there and *carefully* and *very slightly* adjust the proper potentiometers to push the output up to ummm ... maybe a quarter-watt; god forbid a half-watt if you get it just right. Try not to blow out the final in the process, okay? Now, let's say the proper peaking of the base got you that quarter-watt of output, and you locate the base as strategically as possible, and use as short a coax run as possible to get it to the roof to an antenna preferably half-wave size. Notice how I emphasize *carefully* throughout this message: after all, you are not running WLS 890 AM or KOA in Denver, with fifty thousand watts of power to splash all over the northern hemisphere all night long. Your supply is very limited. *They* don't give a damn about Standing Wave Ratio (SWR) and such; why should they ... but you need every tiny bit of power you can tweak out of that base, making sure it reaches the roof and a peice of metal which is conducive to proper and efficient radiation. So here we go: your antenna on the roof is now really blowing smoke. That cordless phone can get signals twice as far as before ... maybe even up to three blocks away when atmospheric conditions are right and a lot of other cordless phones in the vicinity are not being used. You should be all set, right? Wrong ... guess what: the handset can hear the base alright, but can't get back to it. Now you can tweak and peak the handset a little also, but you will *never* get it anywhere near the potential strength of the base. For one, the components in the handset are a little different. At best, it has a chinzy little battery power supply which at any given time is about half-way run down, compared to the base which is plugged into the Edison line always getting lots of juice and always ready to go. For two, the antenna on the handset is a compromise to make it convenient to use. A half-wave antenna would be a burden due to its size (length), so the manufacturer compromised with a loaded coil in the phone making it 'think' its antenna was just as good as any other. The handset can still hear the base alright; a call comes in and the base sends a signal. The handset chirps and you turn it on; but it just keeps on chirping because the base thinks you did not answer; after all it got no signal back from the handset. Maybe you get slightly within range of the base, and because the base is booming so well, the modulation in your earpiece is fine .. perhaps too loud and too over- loaded (depending on what pots you turned when you were in the base messing around! ha ha) but to the person on the other end your voice sounds very distant, faint and even 'broken up' as other signals walk all over your handset. You sound like pooh ... as the CB'ers used to say. Get back within the 'normal' operating range and the handset works fine. All you basically accomplished by tweaking up the base and installing your rooftop antenna was fixing things so the scanner phreaks who spy on your cordless conversations could hear them that much easier. Now instead of snoopy people a half-mile away listening in, people a mile away get to listen also, but a fat lot of good it does your client who gets only frustration when he tries to get more than the 'usual' distance away with his cordless. So after all your experiments at extending the range, the truth becomes known: cordless phone bases are fixed 'the way they are' with the little antennas they have for good reason ... there has to be a more or less equal balance between the base *getting out* and the handset *getting back to the base*. They work at about half their potential (if everything inside was maxed out and the antenna was better quality) because that's the best the handset can do in return. Unlike a broadcast radio station, cordless phones take two to tango. I think you will find attempts to extend the range or overcome barriers such as walls and basements, etc have very limited success at best with cordless phones. If additional range and reliable transmission is what your client needs, we have a name for it: 'cellular service'. What success you will accomplish in increasing the range will only occur provided you also tweak the handset a little, and then the results will be dubious at best. PAT] ------------------------------ End of TELECOM Digest V15 #237 ******************************