TELECOM Digest Sun, 24 Apr 94 07:21:00 CDT Volume 14 : Issue 181 Inside This Issue: Editor: Patrick A. Townson DID Loophole or I'm Screwed Up?? (Daniel H. Chang) Moving Digital Image Data From Mobile Van to Hospital (Douglas M. Tucker) Irish and European ISDN Approvals (fitzgeraldj@netc.ie) 16 Mbps Modem for Real? (maillet@delphi.com) MCI Mail Adds Services Available via Internet (mvm@cup.portal.com) Job Opportunities in ITI, NCB, Singapore (doreen@iti.gov.sig) Channel Bank Recommendations Wanted (Tom Simonds) IDB/Peoples Telephone Plan Merger (Fred Bauer) Remote Interactive Classroom Instruction - How Far We've Come! (Ralph Todd) ISDN Bridge Advice Please (Dean Banfield) DISN Information Request (Rodney Todt) Quality of Long Distance Telephone Lines (T.I. Boogaart) x.25 Networks (Chris Michael) 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 GEnie. Subscriptions are available at no charge to qualified organizations and individual readers. Write and tell us how you qualify: * telecom-request@eecs.nwu.edu * The Digest is compilation-copyrighted by Patrick Townson Associates of Skokie, Illinois USA. We provide telecom consultation services and long distance resale services including calling cards and 800 numbers. To reach us: Post Office Box 1570, Chicago, IL 60690 or by phone at 708-329-0571 and fax at 708-329-0572. Email: ptownson@townson.com. ** 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. For a copy of a helpful file explaining how to use the information service, just ask. TELECOM Digest is gatewayed to Usenet where it appears as the moderated newsgroup comp.dcom.telecom. It has no connection with the unmoderated Usenet newsgroup comp.dcom.telecom.tech whose mailing list "Telecom-Tech Digest" shares archives resources at lcs.mit.edu for the convenience of users. Please *DO NOT* cross post articles between the groups. 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. ---------------------------------------------------------------------- From: hsingnan@ivo.jpl.nasa.gov (Daniel H. Chang) Subject: DID Loophole or I'm Screwed Up?? Date: 24 Apr 1994 00:15:58 GMT Organization: JPL Hello all- I am ordering DID service for the first time and have run across a strange situation. The DID lines ride in our case on eight time slots of a T1 line. We discovered the following: * When someone calls one of the DID numbers, we get an appropriate A/B signal on our side. * We are responsible for sending a wink to get the DID digits (that works fine), then providing the ring signal on the voice band for the sake of the caller on the other end. * Presumably at some point the intended guy picks up the phone, and our equipment seizes the line by raising the A/B bits and patches the call. * Here's the weird part: we discovered that at this point, after we've sent the wink and *before* we seize the line, we are able to patch that line to a phone and perform *full duplex* communications through it! We asked Pac Bell about this, who said the behavior is normal and the caller is not charged until we seize the line, and if we do not seize a timeout will eventually occur. We have determined that timeout is longer than ten minutes! I guess if the DID were carried on analog lines and the PBX had to supply the ring, then the CO having to offer full duplex is inevitable since there is no half-duplex in analog. To me this just says that it is unlikely for the CO to assign the ring responsibility to the PBX -- otherwise the resulting loophole and possibility for abuse seems enormous! Can anyone with more experience shed some light on whether what I described is typical, and what factors am I not taking into account which would make this the signalling behavior which Pac Bell (and I presume other RBOC's) finds advantageous to implement? Some historical perspective would be really interesting too. Dan Chang ------------------------------ From: dtucker@Erebus.rad.uab.edu (Douglas M. Tucker) Subject: Moving Digital Image Data From Mobile Van to Hospital Organization: CIS, Univ of Alabama at Birmingham Date: Sat, 23 Apr 1994 21:08:56 GMT Several months ago the radiologists in my department started providing a mobile radiography service. The service is provided in conjunction with another company that obtains the images, and the docs here read the films for a fee. To date, the way this works is a portable radiography unit is transported to the site (nursing home, outpatient clinic, etc) where an image receptor (called an IP) of a Computed Radiography (CR) system is exposed. The IP is returned to our institution where it is processed using dedicated equipment in a conventional manner. The film is then interpreted by a radiologist. I was approached with the following question: can the device which is used to extract the information from the exposed IP (a CR reader) be placed into some type of vehicle and be used in a mobile environment. In this setting, the CR reader and the radiographic equipment would be transported toq the site. At the site, the IP would be exposed and processed by the CR reader, with the resulting digital image data set saved on a associated computer system. The data would then be transmitted back to the department for processing. The hope is to reduce delays, etc, etc. The question that I have for this group is, provided all of the other issues are worked out, how to get the data from the van back to the department in an efficient and cost effective manner? What options are available? I have heard a little about cellular modems, but understand that they have very limited bandwidth. For this application, each image will be approx 8MByte, with 3-5 images / hour. Thank you for your help. Douglas M. Tucker, Ph.D. Assistant Professor, Department of Radiology UAB Hospital and Clinics 619 S. 19th Street Birmingham, AL 35213 E-Mail: dtucker@rad.uab.edu Phone: (205) 934-1905 FAX: (205) 975-4679 ------------------------------ From: fitzgeraldj@netc.ie Subject: Irish and European ISDN Approvals Date: 24 Apr 1994 06:21:22 -0500 Organization: UTexas Mail-to-News Gateway The Department of Transport, Energy and Communications (the Irish Telecommunications Approvals Body) has recently introduced its interim regulations for the approval of ISDN terminal equipment in Ireland. These regulations will remain until the ISDN Common Technical Regulations (CTRs) are available, which it now appears may not be for some time. The Department has nominated the National Electronics Test Centre (NETC), Forbairt (the Irish Development Agency), to evaluate all approval applications on its behalf. The Centre's application for accreditation has been recommended by the Irish Certification and Laboratory Accreditation Board (ICLAB). Companies wishing to sell their ISDN products in Ireland may apply directly to NETC. In cases where products have already been tested and approved in other countries, NETC will evaluate the relevant documentation and will advise on any further testing which may be required to meet the Irish regulations. NETC will also issue a short report to the Department. A fee will be charged for this service. Applicants with partial foreign approvals may also have the balance of work carried out by NETC. The Centre can provide testing to the new Irish requirements, including NET 3, the European mandatory requirement for Basic Access and to NET 5, the European mandatory requirement for Primary Rate Access. The Centre can also carry out full conformance tests (i.e. beyond the limited NET tests) for both of these services and for ISDN terminal adaptors. Because the Centre has the only Irish laboratory listed in the EC Official Journal for safety testing in accordance with the Low Voltage Directive, NETC can carry out the necessary safety testing, to harmonised European and international standards, on new telecommuni- cations products. American companies who wish to have their ISDN products approved to European standards or their existing approvals evaluated for connection to the Irish ISDN should contact me. Jackie FitzGerald Internet Mail : fitzgeraldj@netc.ie. National Electronics Test Centre Forbairt Glasnevin Dublin 9 Ireland Tel: 353 1 8370101 Fax: 353 1 8370705 / 8379620 ------------------------------ From: maillet@DELPHI.COM Subject: 16 Mbps Modem for Real? Date: Sat, 23 Apr 94 21:59:14 -0500 Organization: Delphi (info@delphi.com email, 800-695-4005 voice) From the May, 1994 issue of {Computer Shopper} Trends & Technology Pg-61 "Small Firm Delivers Big on Digital Signal Compression" Has anyone heard of a small company called Digital Compression Technology (DCT)? It claims it can move 16 Mbps of various kinds of data down a regular telephone line (yes, that's 16 MEGABITS per SECOND). "DCT technology lets telephone wire simultaneously carry four 1.5 Mbps VCR quality video channels; two broadcast quality 3 Mbps video channels; two 1.5 Mbps two-way interactive videoconferencing channels; and ten other channels dedficated to a mix of videophone, fax, and program selection channels." Is this for real or is DCT a couple of engineering students with some vaporware, a fax machine, and a gift for self-promotion? CYBERETSU BBS CONNECTING THE WORLD ------------------------------ From: MVM@cup.portal.com Subject: MCI Mail Adds Services Available via Internet Date: Sat, 23 Apr 94 21:22:05 PDT (Found on the "MCI Mail News" bulletin board:) Date: Wed Apr 20, 1994 10:30 pm CDT Subject: MCI TO OFFER FAX, TELEX AND PAPER BASED MCI MAIL DELIVERY MCI TO OFFER FAX, TELEX AND PAPER-BASED MCI MAIL DELIVERY SERVICES TO INTERNET USERS WASHINGTON, D.C., April 18, 1994 -- To meet the growing demand of the some 20 million Internet users for fast, reliable messaging options, MCI Communications Corporation announced it will provide free subscription to its electronic MCI Mail value-added delivery services. The service expansion, announced at the Electronic Messaging Association's (EMA) 1994 trade show in Anaheim, enables Internet users to send important electronic mail messages to any valid facsimile, telex, postal or courier address worldwide, 24 hours a day, 7 days a week, at standard MCI Mail rates. The company plans to make these delivery options available in June to Internet users who register with MCI Mail. "The demand for more sophisticated messaging and information services will grow exponentially as businesses and consumers continue to take advantage of the capabilities developed through the convergence of multimedia, computers and telecommunications," said Marilyn Bardsley, MCI's vice president for messaging and information services. "Our efforts to expand MCI Mail services to the Internet user community is part of our overall networkMCI vision to harness technologies and turn them into real-world communications tools," said Bardsley. While Internet users have been able to exchange electronic mail messages and binary files with MCI Mail users since 1989, they did not have access to message delivery options or enhanced message handling capabilities commonly used by MCI Mail customers for years. Internet users must either go outside the Internet to send messages via other delivery methods or obtain them through specialized commercial providers on the Internet whose service offerings may be limited by available delivery choices and geographic coverage. With these new capabilities, Internet users can take advantage of MCI's full range of service options and enhanced features which include electronic message transfer to letterhead and use of signature graphics; image transmission via fax; alternate addressing when sending a fax; and automatic retry for fax and telex. According to Vinton G. Cerf, MCI's senior vice president for data architecture and president of the Internet Society, "the Internet community has always used electronic mail to communicate with associates. "Now, with the growth in the commercial Internet, we anticipate these millions of users will need access to reliable messaging services to supplement their e-mail correspondence. MCI Mail's global service is equipped to meet those needs," said Cerf. When the new options are available, Internet users will be able to register electronically for the services. Registration entitles users to have their mailbox information included in MCI Mail's online directory, as well as access to MCI Mail customer support. The cost to use these value-added services will be at the standard MCI Mail rates for fax, telex, postal and courier delivery. For further information and registration, Internet users should send an e-mail message to: MCI-info-request@gatekeeper.mcimail.com and type `help' as the text of the message. MCI also will be providing information about the new service at the EMA trade show in the MCI exhibit booth #210. MCI Communications Corporation headquartered in Washington, D.C., offers a full range of domestic and global telecommunications services through one of the world's largest state-of-the-art networks. The company, with 1993 revenue of nearly $12 billion, is the second largest long distance provider in the U.S. and has more than 65 offices in 60 countries and places. ------------------------------ From: doreen@iti.gov.sg (Doreen from NCS) Subject: Job Opportunities in ITI, NCB, Singapore Organization: National Computer Board, Singapore Date: Sun, 24 Apr 1994 06:45:43 GMT BE PART OF SINGAPORE'S VISION TO CREATE AN INTELLIGENT ISLAND The Information Technology Institute (ITI), the applied R&D arm of the National Computer Board, seeks to accomplish its mission of creating and deploying advanced IT innovations by working with local and international companies in joint ventures and projects. Our R&D efforts are industry-driven. We focus on innovations which would significantly improve our partners' competitive advantage, and products that have commercial potential. We invite applications from suitably qualified candidates for the position of: * Senior R&D Engineer * You are expected to set directions and provide technical leadership to the communication product development group. In addition, you should initate and lead projects as well as provide consultancy to project teams. - Degree in Computer Science or Electronic Engineering; - At least 5 years' substantial experience in data communications or networking preferably with industry; - Creative, self-motivated and good interpersonal skills; If you are keen to pursue a career with us and possess the relevant qualifica- tions and experience, please write to us with a comprehensive resume stating details of your qualifications, current and expected salary, contact number and internet account number. Please send these to: Dr Francis Yeoh Director, Research & Development Information Technology Institute 71 Science Park Drive Singapore 0511 Alternatively, you may wish to respond through internet account: doreen@iti.gov.sg ------------------------------ From: tom@interaccess.com (Tom Simonds) Subject: Channel Bank Recommendations Wanted Date: 23 Apr 1994 19:45:18 -0500 Organization: The second InterAccess INN server Our company is looking to buy channel banks. Can anyone recommend any brands/manufacturers? If so, phone numbers or city/state would be extremely helpful. Please email to tom@interaccess.com Tom Simonds tom@interaccess.com 708-671-3469 ------------------------------ Date: Sat, 23 Apr 94 13:20 EST From: Fred Bauer Subject: IDB/Peoples Telephone Plan Merger I think that the readers of the Digest may be interested in the latest merger in the telecom industry ... Fred Bauer IDB COMMUNICATIONS SIGNS LETTER OF INTENT TO MERGE WITH PEOPLES TELEPHONE COMPANY IDB EXPECTS COMBINATION TO BOOST EARNINGS LOS ANGELES, CA and MIAMI, FL - APRIL 21, 1994 -- IDB Communications Group, Inc. (NASDAQ:IDBX) and Peoples Telephone Company, Inc. (NASDAQ:PTEL) today jointly announced they have signed a letter of intent under which IDB will merge with Peoples. Shareholders of the Miami-based Peoples will receive 1.1 shares of IDB Communications common stock for each share of Peoples common stock, subject to possible adjustment based upon IDB's stock price prior to closing. As of March 31, 1994, Peoples Telephone has approximately 15.8 million common shares outstanding and approximately 3.1 million common shares issuable upon the exercise of outstanding options and warrants at an aggregate price of approximately $23 million. The transaction will be effected as a pooling of interests, and will not be taxable to current Peoples shareholders. IDB Communications expects the merger to boost its 1994 earnings per share. Peoples has been in the public pay telephone business since 1985. The Company has an installed base of approximately 50,000 public, inmate and cellular pay telephones located in 46 states. During recent years Peoples has leveraged its industry expertise to expand into related telecommunication businesses including correctional facility telephones, cellular telephone rentals and prepaid calling cards. The proposed acquisition is subject to satisfaction of customary conditions, including completion of due diligence by both parties, execution of a definitive agreement, approval by the shareholders of both companies and certain regulatory filings, and is expected to be completed by the end of 1994. Jeffrey P. Sudikoff, chairman and CEO of IDB, stated, "One of our key goals in 1994 is to expand IDB's presence in the domestic telecommunica- tions marketplace. The merger with Peoples will accomplish this objective. Jeff Hanft and his team have built Peoples into the largest independent operator of public pay telephones in the United States. Combined with the company's related telecommunications services, Peoples currently generates more than 300 million minutes of long distance traffic a year. As a result, Peoples and IDB will have the foundation for a highly profitable domestic public switched network." "We fully expect this combination to have a positive impact on 1994 IDB earnings per share. By applying many of the principles we have successfully used in acquisitions during the past few years we expect to significantly enhance the operating strengths of Peoples while vastly expanding our domestic marketing capabilities," Mr. Sudikoff added. Jeff Hanft, CEO of Peoples stated, "IDB has emerged as the most innovative, rapidly growing telecommunications company in the world. We at Peoples share many of the same visions and strategic approaches of IDB's management team. We look forward to working with IDB and believe that all of our customers, employees and shareholders will benefit from the combination of the two companies." IDB Communications Group, Inc. is a global telecommunications company that operates a domestic and international communications network providing its customers with international private line and long distance telephone services, radio and television transmission services, facsimile and data connections, mobile satellite communications capabilities and the design and integration of satellite networks worldwide. Peoples Telephone Company, Inc., one of the nation's leading public communications companies, owns and operates approximately 50,000 public, inmate and cellular pay telephones in 46 states. For the year ended December 31, 1993, the Company reported revenues of $121.8 million, an increase of 63%, net income of $5.3 million, an increase of 64%, and cash flow from operations of $27.5 million, an increase of 54%, all as compared to the year ended December 31, 1992. ------------------------------ Date: Sat, 23 Apr 1994 20:05:58 EST From: Ralph E. Todd Subject: Remote Interactive Classroom Instruction - How Far We've Come! Greetings! I am the graduate student in the Telecommunications program at George Mason University (GMU) who submitted the request for information on conferencing on the Internet in early March. On behalf of my class project group, which formed to implement the solution that evolved from the many thoughtful responses I received, I wanted to inform you of our progress. You may recall that the immediate application is interactive televised graduate instruction. The prototype course, "Taming the Electronic Frontier," is taught by Dr. Brad Cox and televised on regional cable television. Most of the students, including an entire section, are in the TV audience. These tele-students had no way of participating in the interactive dimension of the course. Subsequent to publication of my request, I received a consensus response among TELECOM Digest subscribers that Internet Relay Chat (IRC) would provide an effective solution. With the combined dedication and effort of my fellow group members Umar Badeges, Leesia Huffner, Altaf Khan, and Cynthia Roubie, an extremely supportive computer system manager, and an enthusiastic and helpful television producer, Remote Interactive Classroom Instruction (RICI) made its debut at George Mason University on April 19. Students in the TV audience used their PCs at home to connect to the university Internet host computer, and join in an IRC conference with Dr. Cox during his lecture. The "mesg n" command was used in advance of initiating IRC to block distracting messages, and the "mode * +k" command, used by the professor when opening the channel, kept out intruders; we had several interruptions by "bots" while conducting group meetings on IRC. Our first RICI session was a resounding success! We have created student and instructor Guides to Using RICI, which along with a Guide to Future Enhancements will be available on the GMU Internet Gopher. Identified future enhancements include a switch to display IRC text on-air, audio conferencing including voice-delay, and videoconferencing to regional libraries using local cable television channels. We welcome questions and comments. Ralph Todd > rtodd@mason1.gmu.edu (703) 658-9668 George Mason University Telecommunications Program [TELECOM Digest Editor's Note: What a really great report! I was one of many people a few years ago when IRC was first developed and put into use who wondered what real benefit it would have to the Internet. It has been often-times just a huge waste of network resources, but your report today shows there is a lot of good it can do. PAT] ------------------------------ From: idddsb@iddss1.iddis.com (Dean Banfield) Subject: ISDN Bridge Advice Please Date: 24 Apr 1994 02:36:04 GMT Organization: IDD Information Services Hi, We have a 10baseT Ethernet lan and would like an outlier individual to have access on a hardwired basis. ISDN sounds great, but I have no idea what's required here. You take the 64kpbs 'B' channels and then using a 'bridge?' you convert the serial data to 10baseT? Who makes bridges? At what prices? I assume higher price translates into higher performance. Any info appreciated. Thanks. Dean Banfield IDD/Information Svcs 90 Grove St Ridgefield CT 06877 ------------------------------ From: rtodt@relay.nswc.navy.mil (Rodney Todt) Subject: DISN Information Request Organization: NAVAL SURFACE WARFARE CENTER Date: Sun, 24 Apr 1994 03:12:57 GMT Can anyone in this group provide me with a pointer to online information about DISN. I am specifically looking for a map and how to get connected information. Thanks. Rodney Todt DDN Mail: rtodt@relay.nswc.navy.mil Naval Surface Warfare Center Phone: (703) 663-4146 Dahlgren Division DSN: 249-4146 Code E81, Networks Branch FAX: (703) 663-1952 Dahlgren, Virginia 22448-5000 ------------------------------ Date: Sun, 24 Apr 1994 12:39:59 GMT From: T.I.Boogaart@research.ptt.nl (Boogaart T.I.) Subject: Quality of Long Distance Telephone Lines Reply-To: T.I.Boogaart@research.ptt.nl Organization: PTT Research, The Netherlands I would like to know if anyone has conducted research on the quality of long distance telephone lines. With "Quality" I mean the amount of noise and echo (e.g. signal noise ratio). In particular, I want to know if it is at all feasible to perform speech recognition / speaker verification over long distance lines. The focus is on the quality of lines to Europe, but any information on the subject (references, pointers, hints) is welcome. Please send e-mail to me directly, as I don't subscribe to this newsgroup. I'll summarize if there is enough interest. Thanks in advance, Tineke Boogaart ------------------------------ From: cm@nwu.edu (Chris Michael) Subject: x.25 networks Date: 23 Apr 94 17:20:59 GMT Organization: Northwestern University, Evanston, IL USA Reply-To: cm@nwu.edu (Chris Michael) I'm looking for data connectivity between Chicago and Milan Italy. I'm guessing that X.25 will be cheaper than a leased line, but I'm having a heck of a time finding anyone to quote me a price. Does anyone have any thoughts about relative pricing? I assume Telenet and Tymnet are still around. Anyone know where? Thanks, christopher michael, george s. may international, 708-825-8806 x 395 ------------------------------ End of TELECOM Digest V14 #181 ****************************** -------------------------------------------------------------------------------