TELECOM Digest Sat, 18 Dec 93 03:10:00 CST Volume 13 : Issue 824 Inside This Issue: Moderator: Patrick A. Townson Updated Summary of T1 Equipment With Modem Banks etc. (Aninda Dasgupta) Re: Two Cellphones With Same Number? - Not Permitted (Robert J. Keller) Mobilnet - Do They Know This? (Douglas Adams via Aaron L. Dickey) Re: PCS Questions (Samir Soliman) Re: Wireless LANs (Lynne Gregg) Re: Saudi Arabia NANP Area Code (Tony Harminc) 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. Subscriptions are available at no charge to qualified organizations and individual readers. Write and tell us how you qualify: telecom-request@eecs.nwu.edu. 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You can reach us by snail mail at Post Office Box 1570, Chicago, IL 60690 or Fax at 1-708-329-0572. ---------------------------------------------------------------------- Date: Fri, 17 Dec 93 14:20:07 EST From: add@philabs.Philips.Com (Aninda Dasgupta) Subject: Updated Summary of T1 Equipment With Modem Banks etc. [This is an updated version of a summary I posted a few weeks back. This article has more recent information obtained from USRobotics. Also, it gives a "vanilla" solution using DACS and channel banks. For those who are not familiar with T1 terms and equipment, there was a nice article on the TeleTech mailing list by scott@jackson.lambda. com (Scott Statton N1GAK) on Wed, 15 Dec '93, that explained some of the T1 terms and equipment.] A number of people from the net asked me to forward whatever information I have received regarding equipment needed to connect 24 modems to a T1 line. Below I have described the main features of each. All this information is what I have assimilated from market-speak and brochures of the vendors. Summary of my application's needs: I want to provide two kinds of services to my geographically distributed salespeople; both services are to be provided from a workstation-based server. Service 1: Salesperson dials in from his laptop and on my end I want to dump some ASCII and graphics messages on his laptop screen - pretty much like a remote terminal server. Service 2: Salesperson dials in from a POTS telephone, uses DTMF keys to choose a service and gets messages played back and/or a fax sent to a fax machine - very much like voice-mail systems, banks offering credit card balance information and fax-back systems. I need the two services to be served off one workstation because the information accessible via the two services (using modems or telephone sets) is identical and because I want to aggregate my incoming lines onto a single T1 so that I can get good LD rates from my LD provider. Vendors that have products that allow offering such services are listed below. 1) US Robotics - Total Control WAN Hub ----------------------------------- This product is offered as a chassis and various options on cards. They have a dual-T1 card with drop-insert capabilities, frac. T1 enabled, accepts ANI/DNIS and requires no external CSU. The DSP-based quad-modem cards have built-in fax-modem (V.32bis) capabilities, can access DNIS, can load DNIS-dependent modem configuration, will (someday) route the data to LAN adapters (instead of RS-232 ports) and can originate and terminate fax/modem calls. USR also talks about making LAN adapter cards (Enet and TR) available in late '94, which will allow direct connections to a Token-ring or Ethernet LAN. They will also have a LAN Gateway card that will work in conjunction with the LAN adapters to route data to/from the quad modems to the LAN. TCP/IP and X.25 will be initially supported on the Gateway cards, and Appletalk, etc. will be added later. Any application specific protocol of your choice can be downloaded onto the Gateway card. This will allow you to use any home-brewn protocols for transactions, data exchange, etc. between remote applications. A terminal server card will be avialable around mid-'94. Voice cards (with RJ11 output, I guess) will be available "later '94." USR will also have ISDN PRI, X.25 and Frame Relay cards that go in the same chassis. The chassis and most of the cards are controllable/monitorable using SNMP, either from a PC (with software available from USR) or from any other SNMP host on the LAN. Some of the cards are also controllable via RS-232 dumb terminals. For more (and perhaps accurate) information, contact US Robotics at (800) 342-5877. I spoke with Michael Cashman, Ext. 5636 (Marketing/Sales). I also spoke with Don Balton - (708) 982-5091 who used to head the group that designed this product, and Lauri Lentz in Public Relations. 2) Primary Access -------------- I found out about Primary Access from, among others, its founder, Jim Dunn. They are reachable by email. They seem to have a larger installed base of their product as compared to the USR product described above. This prouduct is also a chassis based system. The single-T1 card has drop-insert capabilities, is not capable of frac. T1 (from what I could gather from their glossies), needs an external CSU (but only for loop-back testing) and accepts ANI/DNIS. However, the ANI/DNIS is accessible to a host computer only if you use an X.25 link between the chassis and the host. This means, in order to get the ANI/DNIS, you need to buy an X.25 card for the chassis and an X.25 card and software for the host. The dual-modem cards are V.32bis compatible, can do DTMF decoding, can originate and terminate modem calls, and they promise routing of modem data to LANs within the next year. These cards don't seem to be as feature rich as the USR cards (e.g. on the fly, DNIS-dependent configuration download, etc.). They offer X.25 cards and Frame Relay too. Network management is done using CMIP. All software on the cards can be downloaded for upgrades. Voice call support is provided using their 8-port FXS cards (something that is lacking in the USR offering at this time). They have promised Ethernet support in about a year. They assured me that they can price their products very aggressively. For more information call: (619) 536-3000 Fax: (619) 693-8829 3) Dialogic -------- This is a all-in-a-PC solution. Dialogic offers a T1 interface card for the IBM PC bus. This card provides access to ANI/DNIS, has drop-insert capabilities and requires an external CSU for loop-back testing. They have various versions of the T1 card, offering various options for the number of T1 ports. Also offered is a PC-based four-channel Voice card that does DSP-based call processing. Combined with Dialogic's voice-processing software (PCM encode/decode API) and DTMF recognition capabilities, this card provides an excellent way to implement voice-based services. Dialogic also offers fax boards that will allow you to send out faxes from the PC. The PC, equipped with a LAN adapter card can, via the application software route all data to a network. I am not aware of network monitoring features (SNMP or CMIP). Also missing is any V.32bis modem capabilties. One attraction of going the Dialogic way is the elimination of any cabling which is needed to connect the USR or Primary Access products to any host system (e.g. RS-232, twisted-pair etc.). All the cards use Dialogic's PEB bus for internal data transfers. For more information call Dialogic Sales and Technical Support: (201) 334-1268. 4) IBM's CallPath Line of Products: ------------------------------- IBM offers a uniform API to interface to phone systems, independent of the the PBX vendor and the host system platform. e.g. one could use the same programs to implement CallPath-based applications on MVS, AS/400, OS/2 and AIX based systems and interface to PBXs from Rolm, NT, etc. One requirement is the PS/2 based CallPath SwitchServer/2, which seems to be a system that has hard-wired links to the PBX and sits on the LAN and serves all requests for operations from the CallPath host. The host to SwitchServer link is supported using SNA LU6.2 (yuk!!). They support DID, DNIS, CLID, ANI etc. and have T1 boards for the RS/6000 (I am not aware if they have boards for the PS/2 and mid to main frame systems, but I assume they do). Although an interesting product with a seemingly rich API to perform all kinds of call routing etc, the main drag is the PS/2 requirement to interface to a PBX (what if I don't have a PBX?) For more information call: (800) IBM-CALL and ask for information on CallPath line of products. A Vanilla Solution using DACS, Channel Banks and CSU/DSUs An alternative to all the above solutions, and perhaps much more messy (in terms of writing purchase orders and cabling), is to use a CSU box to terminate the T1 span. Then, use a DACS+Channel Bank to do the splitting of the lines into modem and voice calls. However, I am not sure how one would use two 800 numbers -- one for modem calls and one for voice, and somehow have the DACS recognize the DNIS and split them accordingly. Do they make DACS or Channel Banks that will use DNIS to split the DSO channels? (I bet they do.) After the Channel Bank, the modem lines would have to be fed into v.32bis modems. This might create a nasty cable spaghetti between the Channel Bank and the modems. Besides, buying and managing 24 or 48 modems is expensive, right? Then of course there is the cabling from the modems to the host's serial ports. I have seen a Wireless RS-232 box that transmits to 500 ft. But I don't know how 24 of them would perform sitting next to one another. The advantage of this solution is that you can buy used equipment for cheap (there are plenty of used telco equipment vendors) and get something up and running. [The following sources were mentioned in an article by scott@jackson.lambda.com (Scott Statton N1GAK)]: Channel Banks: Newbridge, Wescom DACS: Fredericks' Engineering CSU/DSU: Kentronics, AT&T etc. Summary and Wish List: The Primary Access and USR offerings both look attractive. I wish Primary Access delivered ANI/DNIS without X.25. I wish both USR and Primary Access had LAN adapters for their chassis so that I wouldn't need to run 24 RS-232 cables from the modem cards to my workstation. (Getting a workstation equipped with 24 serial ports is quite difficult.) The Dialogic product can be neatly packaged in a PC, but I don't trust a PC to do my important call processing and service providing functions. And Dialogic doesn't provide V.32bis modem-banks in their PC solutions. Finally, I wish the IBM product didn't need a PBX and a PS/2 to interface to it. Disclaimer: ---------- I DO NOT GUARANTEE the accuracy of any of this information. As I said, this is what I have understood or guessed from whatever information I was able to gather directly from the vendors. I might have misunderstood some deficiencies, or unknowingly embellished some features. If so, that was unintentional. If anybody familiar with these products finds any inaccuracies, I'd appreciate being told about it. If anybody knows of any other such products, I would like to hear about them too. Thanks to all those who responded to my queries on this (and other) mailing-list(s). Aninda DasGupta (add@philabs.philips.com) Ph:(914)945-6071 Fax:(914)945-6552 Philips Labs\n 345 Scarborough Rd\n Briarcliff Manor\n NY 10510 ------------------------------ Reply-To: rjk@telcomlaw.win.net (Robert J. Keller) Date: Fri, 17 Dec 1993 23:15:09 Subject: Re: Two Cellphones With Same Number? - Not Permitted From: rjk@telcomlaw.win.net (Robert J. Keller) Here is what the Federal Communications Commission has to say on the subject: :: Quote :: PUBLIC NOTICE FEDERAL COMMUNICATIONS COMMISSION COMMON CARRIER PUBLIC MOBILE SERVICES INFORMATION October 2, 1991 Report No. CL-92-3 CHANGING ELECTRONIC SERIAL NUMBERS ON CELLULAR PHONES IS A VIOLATION OF THE COMMISSION'S RULES It has come to the attention of the Mobile Services Division that individuals and companies may be altering the Electronic Serial Number ( ESN) on cellular phones. Paragraph 2.3.2 in OST Bulletin No. 53 (Cellular System Mobile Station - Land Station Compatibility Specification, July, 1983) states that "[a]ttempts to change the serial number circuitry should render the mobile station inoperative." The 1981 edition of these compatibility specifications (which contains the same wording) was included as Appendix D in CC Docket 79-318 and is incorporated into Section 22.915 of the Commission's rules. Phones with altered ESNs do not comply with the Commission's rules and any individual or company operating such phones or performing such alterations is in violation of Section 22.915 of the Commission's rules and could be subject to appropriate enforcement action. Questions concerning this Public Notice should be addressed to Steve Markendorff at 202-653-5560 or Andrew Nachby at 202-632-6450. :: End Quote :: The staff has informally opined (although the Commission has not yet formally ruled) that the foregoing prohibits, in addition to the direct cloning and/or manipulation of the ESN, many of the other schemes to get around it by "intercepting" and "translating" the ESN. They have proposed the following rule which will likely be formally adopted sometime early next year: :: Quote :: 22.919 Electronic serial numbers. The Electronic Serial Number (ESN) is a 32 bit binary number that uniquely identifies a cellular mobile transmitter to any cellular system. Each mobile transmitter must have a unique ESN and must comply with the following specifications. (a) The ESN must be factory set and must not be alterable, transferable, removable or otherwise able to be manipulated in the field. (b) The ESN host component must be permanently attached to a main circuit board of the mobile transmitter and the integrity of the unit's operating software must not be alterable. The ESN must be isolated from fraudulent contact and tampering. If the ESN host component does not contain other information, that component must not be removable, and its electrical connections must not be accessible. If the ESN host component contains other information, the ESN must be encoded using one or more of the following techniques: (1) multiplication or division by a polynomial; (2) cyclic coding; (3) the spreading of ESN bits over various non-sequential memory locations. (c) Cellular mobile equipment must be designed such that any attempt to remove, tamper with, or change the ESN chip, its logic system, or firmware originally programmed by the manufacturer will render the mobile transmitter inoperative. :: End Quote :: As far as staff is concerned, the proposed rule merely clarifies what is already the law, but they feel that the clarification in necessary because many in the industry are coming up with so many novel ways to accomplish the same result in clever ways. IMO, this is not something to be taken lightly for two reasons: (1) the FCC has gotten rather aggressive in recent years in the number and size of forfeitures (read "fines") imposed for (even relatively minor) rules violations, and (2) doing something like this when your carrier does not authorizes subjects you to the risk that your cellular unit will be negatively listed (and therefore rejected as a fraudulent unit). Note, however, that the staff does _not_ consider it to be a violation for the cellular carrier to offer this capability by doing some programming at the cellular switch that associates a single phone number with two or more _different_ ESN's. Apparently some carriers are starting to do this. Bob Keller (KY3R) Tel +1 301.229.5208 rjk@telcomlaw.win.net Fax +1 301.229.6875 rjk@access.digex.net CIS 76100,3333 ------------------------------ From: kieran@world.std.com (Aaron L Dickey) Subject: Mobilnet - Do They Know This? Organization: The World Public Access UNIX, Brookline, MA Date: Fri, 17 Dec 1993 21:10:23 GMT The following is being forwarded for the benefit of Douglas Adams: adamsd@cerf.net (Douglas Adams) writes: There have been some very expensive and elaborate ads on CNN recently for Mobilnet. As far as I can divine (the ads are heavier on production values than on information) they are offering a nationwide cellular service which eliminates the need for fiddling about with roaming codes etc. If this is what they are offering then I am extremely interested in it -- definitely a potential customer. Though I 'm British, I spend a great deal of time travelling round and round the States and 'cell-comms-made-simple' is exactly what I want. Right at the end of the ad they flash up a 1-800 number for enquiries. By the time I've grabbed a pencil its gone and I haven't got the number. This has happened several times. I suddenly realize it's _that_ ad, (it takes a while to spot it because it starts out like an ad for shampoo or beer or something) and have just been too late to get the number. So I've tried the 800 information service, which has no listing for Mobilnet. Now, I can't help wondering if the people at Mobilnet are sitting manning their phones and thinking 'Hmmmm -- doesn't seem to be much demand for this service. Maybe the folks out there don't really want a national cellular system ...' I think there should be some kind of award for advertising of this nature. Incidentally -- if anybody _does_ have the Mobilnet number I'd be glad to have it -- provided they haven't shut down the business for lack of demand. Douglas Adams adamsd@cerf.net (current) dna@dadams.demon.co.uk (dormant) (message passed along by) Aaron Dickey kieran@world.std.com [Moderator's Note: I tried 800-555-1212 just now hoping to find an answer, but 800 directory has nothing listed for the company. Anyone else know how to reach them? PAT] ------------------------------ Date: Fri, 17 Dec 93 20:26:26 -0800 From: Samir Soliman Subject: Re: PCS Questions At 11:31:06 CST 12/14/93 Kyle Griffin wrote: > Although there are strong proponents of making GSM (or a modified > version) a US standard, there's no guarantee that will happen. The FCC > has stated that they would rather let the market determine standards > rather than dictate any. There are also proponents of CDMA. I've seen > some of the TDMA-CDMA dialogue in this digest. I'm not on either > "side" of the issue. From what I've read (from people not related to > any company making either type of equipment), as well as an > acquaintance at Bellcore, there is a general feeling that, as far as > capacity is concerned, when all is said and done, they're going to > come out about equal in terms of increased capacity over cellular AMPS > (approximatly 7 to 1). I don't want to argue numbers here. But keep in mind that GSM is not designed for capacity or spectral efficiency. The design objective for GSM was politically motivated. In the US spectrum is becoming a very expensive commodity and a need for an efficient multiple access scheme becomes a necessity. I recommend that every one interested reads the article published by THE ECONOMIST entitled "Falling to bits" dated May 29, 1993. In that article, the author writes "The ambitious eight fold gain that Europe is aiming for has proved equally elusive. GSM averages a two-to-threefold gain. In Hong Kong, where the complicated city-scape tends to disperse the signal, GSM has managed to improve things by a mere 50%" The PCS radio environment is similar, if not worse than the Hong Kong environment (small cells, dense urban, severe mulipath, high traffic volume, in-building coverage requirements, etc. ...). I would like to hear from anyone who worked or still working on the GSM system in Hong Kong. What was (is) his/her experience with getting the system to work in Hong Kong? What is the capacity of that system compared to AMPS?. I would like also to hear how painful was it to replan the frequency at least once a month or as often as you add one more sector or cell as the system grows with time. Samir Soliman Qualcomm Incorporated ------------------------------ From: Lynne Gregg Subject: Re: Wireless LANs Date: Thu, 16 Dec 93 08:57:00 PST Original note: > I am looking for a way to send Ethernet across a public street. Somebody > told me there is a $2500 pair of laser devices that can do that. Another Response: > John Levine, johnl@iecc.com, {spdcc|ima|world}!iecc!johnl > I'm surprised that nobody's mentioned NCR Wavelan. It's a 2 mb/sec Another option is Motorola Altair. They may be above 2mb by now. They also had some interesting methods of extending distance, combining both infrared (line of sight) and radio receivers. Multiple protocol support's available, too. Regards, Lynne ------------------------------ Date: Sat 18 Dec 93 00:07:58 EST From: Tony Harminc Subject: Re: Saudi Arabia NANP Area Code > [Moderator's Note: Yes, Saudi Arabia had an international country code > like all other countries, but it also had an 'area code' which could be > dialed from the USA for the administrative convenience of some people. > The oil industry? I dunno. Anyone remember the 'area code' number, and > does it still work today? PAT] I have a business card that I got in 1981 or 1982 from someone working in Saudi Arabia. It is laid out like this: ---------------------------------------------------------------- KINGDOM OF SAUDI ARABIA Ministry of Finance and National Economy The National Center for Financial and Economic Information Asst Coord for Tech Operations USREP/JECOR/NCFEI P.O. Box 6902 APO New York 09038 Riyadh, Saudi Arabia Ph: 404-0544 Ph: 404-3945 ---------------------------------------------------------------- The same (I presume) information is on the other side in Arabic. There is no area code -- just seven digits for each number, but perhaps the implication that both are NYC numbers, but one rings in Riyadh? Or perhaps both are Riyadh numbers, but one rings in a P.O. box in New York. :-) Tony Harminc ------------------------------ End of TELECOM Digest V13 #824 ****************************** ****************************************************************************** Downloaded From P-80 International Information Systems 304-744-2253