(If you suspect you may be using the wrong COM port on your PC, or that there may be a conflict between COM ports, this is the place to look) 4

Introduction Introduction

Hey, You Can Call Us!

This guide is intended for those of you who would like to troubleshoot connectivity problems like unexpected disconnects on your own, but need a little information to get started.

Note that when you have problems connecting or maintaining a connection to Novia, you should first give us a call. Our technical support line is 895-2633 and our support hours run from 8:00 A.M. to 8:00 P.M. When all of our technicians are out of the office on field support calls, the main number will roll over to our answering service, which will take down the pertinent information and send your name and number to a technician's digital pager. Calling us is a good way to rule out an obvious problem such as a password change or a faulty modem on our end. It's better to call us before you invest a great deal of time and energy in troubleshooting a localized problem that might not actually exist.

Why High Speed ModemsWhy High Speed Modems

Can Be Problematic

There was a time when a guide to troubleshooting a modem could have consumed no more real estate on the printed page than a postcard. Two trends have dramatically altered that picture:

modems have become much faster

as a consequence, we ask our modems to do a great deal more than we once did

Today, a high-speed modem can transmit 28,800 bits of digital information in a second, making it roughly one hundred times faster than its immediate ancestors from the mid-to-late 1980s. What is more, today's high-speed modems can typically send and receive faxes, along with hordes of data - images, sounds, and packet-based communication for access to the Internet - that would have been seen as thoroughly exotic just ten years ago

In spite of the fact that nearly every new PC sold has a built-in (or optional built-in) modem, modems are still in a sense an exotic add-on to your computer. If your monitor needs servicing, it will tell you: it will go dim or flicker. If your printer needs servicing, it will constantly print black spots or horizontal stripes on the pages it produces. If your modem needs servicing, it will fail to connect to online services at its highest possible speed or simply fail to connect period, right?

Not necessarily.

It could be that a software misconfiguration has your modem thinking it's a FAX machine while you think it's your on-ramp to the Internet. It could be that your home's telephone wiring is substandard or that you have a "dirty" pair of wire between the modem and the telephone company's central office, the first location where your calls are intercepted and routed to the appropriate destination number.

This guide is an effort to help you solve connectivity problems and get the most out of your account with Novia.

This guide will be organized by the popularity of the question or problem - most commonly asked questions and most frequently occurring problems discussed first. If the background information accompanying these questions or problems isn't your cup of tea, skip ahead to the last page of the document for "quick tips," a checklist of symptoms and possible remedies for typical modem problems.

Questions Often Asked by

Users of High-Speed Modems

Of all the jobs I would never want to have, I think being a telephone support specialist for a modem manufacturer would come close to topping the list. These unsung heroes of the telecommunications world daily field calls from bitter, resentful customers who claim they have been cheated by modem makers who promised 28,800bps connections when in fact they can only connect at 21,600 or 24,000. The fact of the matter is that the existing telephone infrastructure is hard-pressed to accommodate a transmission speed or throughput of 28,800bps (bits per second), particularly when a given connection is routed through several telephone switches.

For example, Novia's Research and Development Manager Rivaldo Rustam never fails to connect to Novia at a speed of 28,800bps. This is because he lives in that part of the city which is served by the same telephone switch or CO (central office) that Novia's bank of dial-in modems utilizes. This "single hop" to Novia's modem bank greatly reduces the number of opportunities for the signal to degrade. Novia's Customer Service Manager Matt Heys lives a switch or two away and normally connects at 24,000 bps.

This creates a rather interesting scenario in which Omaha's Internet Service Providers trade flocks of dissatisfied customers because of the "geography behind the telephone call." We often hear new customers tell us, "I chose you folks over Brand X because I can always connect at 28,800bps to your service." Well, in the spirit of fairness, the customer's inability to connect to Brand X probably has nothing to do with a problem on Brand X's side.

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I once thought "modems were modems." In my life I have owned seven different modems and each has worked flawlessly, but I've also been educationally privileged enough to make purchase recommendations to others about modems that have come back to haunt me. In one particular instance, a 14.4kbps modem I recommended contained a manufacturer's defect, as did the replacement unit the company shipped to remedy the situation! Yes, it is possible to buy a dud modem. If you suspect that your modem possesses a defect, the best approach is to follow the instructions in this guide. If all of the solutions contained herein do not improve the situation, it might be time to raise an eyebrow or two regarding the modem itself. This is not to say that this guide is by any means comprehensive. That would require a yellow-pages-sized tome. It does cover the most common problems we experience in providing technical support to our customers.

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Without going into all the gory details, yes. While this is not an issue for Macintosh users, PCs do not pay equal attention to all of their COM ports. COM2 has sufficient priority for high-speed communications. Installing your modem on COM1, COM3, or COM4 is not recommended.

solution:

As a general rule, the ideal COM port for your modem is COM2, particularly if your mouse connects to COM1. It is also not recommended that you have devices on COM2 and COM4 or COM1 and COM3 simultaneously. If you have an external modem, switching the COM port is a simple matter of connecting the serial cable to a different RS-232C port on the back of your computer. If your modem is internal, give us a call at 895-2633 for additional assistance.

Common Problems And Software Settings You Can Change To Eliminate ThemCommon Problems And Software Settings You Can Change To Eliminate Them

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This error is common to both Macintoshes and PCs, although it tends to be more rare in Macintoshes running System 7.5.3 and PCs running Windows95. More often than not, what you are experiencing is a form of memory fragmentation. When you connect to the Internet, your computer needs to load a piece of software known as a "TCP/IP" stack. This problem usually occurs when the TCP/IP stack loads but cannot operate properly due to memory constraints. Prior to upgrading my Macintosh to 7.5.3, I often found that if I logged onto the Internet after having run Microsoft Word or PageMaker, I could not login successfully. When I did connect without difficulty, punching "www.novia.net" into my web browser's location field often produced a "The site www.novia.net does not have a DNS entry" error message. I have talked many Windows 3.11 users through similar problems.

solution

Restart your computer.

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Before your modem actually dials a telephone number, it needs to be initialized. Your software package accomplishes this by issuing a series of commands to the modem which configure its speed, data compression and error correction capabilities. If this string is incorrect, you will experience difficulties connecting. Where does one change the initialization string setting? In Windows95, it can be found in the Advanced… dialog box under the Properties menu of the modem control panel. Macintosh users will find the initialization string under Modem Init a setting that can be entered or modified by clicking on the Config… button in the Config PPP control panel. If you need help in locating the initialization string setting, give us a call and we'll help you track it down. We can be reached at 895-2633. Once you have located your software's initialization string setting, the best policy is to call your modem's manufacturer, ask for a recommended initialization string, and compare the two. A less reliable (given the rapid rate of change in the industry) method would be to consult the index of common initialization strings below to see if your current string matches up with the one listed for your particular make and model of modem. In an effort to keep up with new error correction and compression standards, modem manufacturers are constantly modifying the chipsets that make up the brains of their products. As such, the correct initialization string for a Boca MV28KL today may not be the correct initialization string tomorrow.

Vendor and Model	String
AT & T Modems
AT&T Comsphere 3800 Plus Series	AT&F^M
AT&T Comsphere 3800 Series	AT&F^M
AT&T Dataport Express V.34 288	AT&F^M
AT&T Dataport Express 14.4 Fax	AT&F^M
AT&T Dataport 14.4 Fax	AT&F&C1&D2X4^M
AT&T Globalyst	AT&F&D2X1^M
AT&T KeepInTouch Card	AT&F^M
AT&T KeepInTouch Express Card 288	AT&F\N7^M
AT&T KeepInTouch Express Card (B1)	AT&F^M
AT&T Paradyne Dataport 14.4	AT&F&C1Q0E0V1X4^M
Boca Modems
Boca Multimedia 14.4	AT&F&C1&D2S95=1^M
Boca MV28KE	AT&F&C1&D2\N3S95=1^M
Boca MV28KI	AT&F&C1&D2\N3S95=1^M
Boca MV34E	AT&FW2&C1&D2S95=1^M
Boca MV34I	AT&FW2&C1&D2S95=1^M
Boca Online Express M144AI	AT&F&D2X1^M
Boca Sound Expression SE14400	AT&F^M
Boca 14.4 PCMCIA	AT&FX4S95=1^M
Boca 14.4	AT&F&C1&D2\N3S95=1^M
Cardinal
Cardinal Accelerator MVP144WIN	AT&F&D2X1^M
Cardinal Fax 14.4	AT&F&C1&D2^M
Cardinal MVP288I	AT&F&C1&D2S95=1^M
Cardinal MVP288XF	AT&F&C1&D2S95=1^M
Cardinal 14.4 DSP	AT&F^M
Cardinal 14.4 PCMCIA	AT&F&C1&D2S95=1^M
Cardinal 19.2 Turbo	AT&F&C1&D2^M
Cardinal 9600	AT&F&C1&D2S95=1^M
Creative Labs Modems
Creative Labs Modem Blaster 14.4 PCMCIA	AT&F^M
Creative Labs Modem Blaster 19.2	AT&F^M
Creative Labs Modem Blaster 28.8	AT&F&C1&D2\N3S95=1^M
Hayes Modems
Hayes Accura 14.4	AT&F&C1&D2S95=1^M
Hayes Accura 14.4B	AT&F&C1&D2S95=1^M
Hayes Accura 288 V.FC	AT&F&C1&D2S95=1^M
Hayes Accura 288	AT&F&C1&D2S95=1^M
Hayes Accura 288B	AT&F&C1&D2S95=1^M
Hayes Accura 9600	AT&F&C1&D2S95=1^M
Hayes Accura 9600B	AT&F&C1&D2S95=1^M
Hayes Compatible (default)	AT&FE1Q0V1&D2X4&C1^M
Hayes Compatible (error correcting)	AT&F&C1&D2&K3&Q5E1V1Q0X4^M
Hayes Smartmodem Optima PCMCIA	AT&F&C1&D2S95=1^M
Hayes Smartmodem Optima Pocket	AT&F&C1&D2S95=1^M
Hayes Smartmodem Optima PCMCIA 14.4	AT&F&C1&D2S95=1^M
Hayes Smartmodem Optima 14.4	AT&F&C1&D2S95=1^M
Hayes Smartmodem Optima 14400+ fax	AT&F&C1&D2S95=1^M
Hayes Smartmodem Optima 14.4B	AT&F&C1&D2S95=1^M
Hayes Smartmodem Optima 288	AT&F&C1&D2S95=1^M
Hayes Smartmodem Optima 288 V.FC	AT&F&C1&D2S95=1^M
Hayes Smartmodem Optima 288B V.FC	AT&F&C1&D2S95=1^M
Hayes Smartmodem Optima 288B	AT&F&C1&D2S95=1^M
Hayes Smartmodem Optima 288+ fax	AT&F&C1&D2S95=1^M
Hayes Smartmodem Optima 9600	AT&F&C1&D2S95=1^M
Hayes Smartmodem Optima 9600B	AT&F&C1&D2S95=1^M
Hayes Smartmodem V-Series Ultra 14.4	AT&F&C1&D2S95=1^M
Hayes Smartmodem V-Series Ultra 9600	AT&F&C1&D2S95=1^M
Megahertz Modems
Megahertz CC3144	AT&F&C1&D2S95=1^M
Megahertz CC324 FM	AT&F&C1&D2S95=1^M
Megahertz CC3288	AT&F&C1&D2W2^M
Megahertz CC396 FM	Setup=AT&F&C1&D2S95=1^M
Megahertz CC5144	AT&F&C1&D2S95=1^M
Megahertz P2144	AT&F&C1&D2S95=1^M
Megahertz P296 FMV	AT&F&C1&D2S95=1^M
Megahertz XJ1144	AT&F&C1&D2S95=1^M
Megahertz XJ124 FM	AT&F&C1&D2S95=1^M
Megahertz XJ196 FM	AT&F&C1&D2S95=1^M
Megahertz XJ2144	AT&F&C1&D2S95=1^M
Megahertz XJ2288	AT&F&C1&D2W2^M
Multitech Modems
Multitech Multimodem 2 Series	AT&FX1^M
Multitech MT 1432 Series	AT&FX4^M
Multitech MT 1932 Series	AT&F&E11X4^M
Multitech MT 2834 Series	AT&F&E11X4^M
Practical Peripherals
Practical Peripherals MC144MT II	AT&F1S95=1^M
Practical Peripherals MC144T2	AT&F1S95=1^M
Practical Peripherals MC144T2-EZ	AT&F1S95=1^M
Practical Peripherals MC288LCD	AT&F1S95=1^M
Practical Peripherals MC288MCII	AT&F1S95=1^M
Practical Peripherals MC288T2	AT&F1S95=1^M
Practical Peripherals MC288T2-EZ	AT&F1S95=1^M
Practical Peripherals Practicard 14.4 PCMCIA	AT&F1S95=1^M
Practical Peripherals PC 288 SA	AT&F&C1&D2S95=1^M
Practical Peripherals PC 288 HC	AT&F1S95=1^M
Practical Peripherals PC 288 LCD	AT&F1S95=1^M
Practical Peripherals PC 288 MT	AT&F1S95=1^M
Practical Peripherals PC144T2	AT&F1S95=1^M
Practical Peripherals PC144T2-EZ	AT&F1S95=1^M
Practical Peripherals PC144HC	AT&F1S95=1^M
Practical Peripherals PC144LCD	AT&F1S95=1^M
Practical Peripherals PC144MT	AT&F1S95=1^M
Practical Peripherals PC288T2	AT&F1S95=1^M
Practical Peripherals PC288T2-EZ	AT&F1S95=1^M
Practical Peripherals PM 14400	AT&F1S95=1^M
Practical Peripherals PM 288 MTII	AT&F1S95=1^M
Practical Peripherals PM 288 HCII	AT&F1S95=1^M
Practical Peripherals PM 288 PKT	AT&F1S95=1^M
Practical Peripherals PM144FX	AT&F1S95=1^M
Practical Peripherals PM144FXHC	AT&F1S95=1^M
Practical Peripherals PM144FXMT	AT&F1S95=1^M
Practical Peripherals PM144HC II	AT&F1S95=1^M
Practical Peripherals PM144MT II	AT&F1S95=1^M
Practical Peripherals PM144FXPKT	AT&F1S95=1^M
Practical Peripherals PM144PS2	AT&F1S95=1^M
Practical Peripherals PM1200SA	ATE1Q0V1X4^M
Practical Peripherals PM9600FXMT	AT&F1S95=1^M
Practical Peripherals PM9600HC II	AT&F1S95=1^M
Practical Peripherals PM9600MT II	AT&F1S95=1^M
Practical Peripherals 14.4 FXSA V.32	AT&F&C1&D2S95=1^M
Practical Peripherals 9600SA	AT&F&C1&D2S95=1^M
Supra Modems
Supra 14.4 V.32 bis	AT&F2S95=1^M
Supra 14.4/Fax	AT&F2S95=1^M
Suprafax 288	AT&F2S95=1^M
SupraExpress Plus 14.4	AT&F2S95=1^M
SupraExpress Plus 14.4i	AT&F2S95=1^M
US Robotics Modems
USRobotics Courier w/ASL	AT&FX4&A1&B1&H1&M4&R2^M
USRobotics Courier HST Dual Std w/ASL	AT&FX4&A1&B1&H1&M4&R2^M
USRobotics Courier HST Dual Std/PC FAX w/ASL	AT&FX4&A1&B1&H1&M4&R2^M
USRobotics Courier HST Dual Std Terbofax w/ASL	AT&FX4&A1&B1&H1&M4&R2^M
USRobotics Courier HST Dual Std	AT&FX4&A1&B1&H1&M4&R2^M
USRobotics Courier Terbofax w/ASL	AT&FX4&A1&B1&H1&M4&R2^M
USRobotics Courier V.32Bis/PC w/ASL	AT&FX4&A1&B1&H1&M4&R2^M
USRobotics Courier V.32Bis/PC FAX w/ASL	AT&FX4&A1&B1&H1&M4&R2^M
USRobotics Courier V.34 (V Everything)	AT&FX4&A1&B1&H1&M4&R2^M
USRobotics Courier 14.4	AT&FX4&A1&B1&H1&M4&R2^M
USRobotics Sportster Mac & Fax 288	AT&FX4&A1&B1&H1&M4&R2^M
USRobotics Sportster PCMCIA	AT&FX4&A1&B1&H1&M4&R2^M
USRobotics Sportster 14400/Fax	AT&FX4&A1&B1&H1&M4&R2^M
USRobotics Sportster 28.8 V.34	AT&FX4&A1&B1&H1&M4&R2^M
USRobotics Sportster 9600/Fax	AT&FX4&A1&B1&H1&M4&R2^M
USRobotics Worldport 14400	AT&FX4&A1&B1&H1&M4&R2^M
Zoom Modems
Zoom 14.4 PCMCIA	AT&F&C1&D2S95=1^M
Zoom 14.4 V.32/V.32bis	AT&F&C1&D2^M
Zoom 14.4 VFP V.32	AT&F&C1&D2S95=1^M
Zoom 14.4 VFX V.32	AT&F&C1&D2S95=1^M
Zoom 28.8 V.34i	AT&F&C1&D2S95=1^M
Zoom 28.8 V.34X	AT&F&C1&D2S95=1^M
Zoom 28.8 VFP	AT&F&C1&D2S95=1^M
Zoom 28.8 VFX	AT&F&C1&D2S95=1^M

Another good initialization string is simply this:

… which will reset any modem to its factory default settings. ATZ is a particularly handy command string if your modem serves double-duty as a FAX machine. Since a fax package and a telecommunications program are going to want the modem for different tasks, one often initializes the modem in a fashion that is inappropriate for the other.

Change the initialization string if necessary and see if connectivity improves.

I believe I have the right initialization string, but I'm still having difficulty maintaining my connection.I believe I have the right initialization string, but I'm still having difficulty maintaining my connection.

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A good number of connection problems can be explained by inappropriate port speed settings. The port speed, sometimes known as the DTE speed, is another throughput statistic. It does not measure the modem's throughput or transmission speed to the outside world but rather the speed at which the computer's serial communications port will accept data from the modem. The average serial port can process information from an attached periperhal such as a modem at a rate of 115,000 bps or higher. Makers of communications software often trumpet the fact that their software can exchange data with the modem at a rate of 115,000 bps or higher. What their hyperbole disguises is the fact that your computer - compelled to divide its attentions between a the serial port and a spreadsheet you may be printing in the background - may have difficulty efficiently processing the serial port buffer's contents at such a high speed, resulting in disconnects, web pages that suddenly stop midway through loading, and "CRC/communications overrun" errors in popular TCP/IP applications like Trumpet Winsock.

Where does one change the port speed setting? In Windows95, it can be found in the Advanced… dialog box under the Properties menu of the modem control panel. Macintosh users will find the initialization string under Port Speed, a drag down menu accessible by clicking on the Config… button in the Config PPP control panel. If you need help in locating the port speed setting, give us a call and we'll help you track it down. We can be reached at 895-2633. Once you have located it …

solution

Users of 14.4kbps modems should use a port speed of 38,400 bps. Users of 28.8kbps modems should use a value of 57,600bps.

Due to extremely poor telephone line quality, we occasionally find that lowering the port speed down to 19,200bps is necessary to establish and maintain a reliable connection - on 14.4 or 28.8 kbps modems, in fact.

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This problem may lie between your serial port and the application to which it is attempting to send information. In Windows 3.11, the task of feeding data back and forth between the two is performed by the Windows communications driver. Contrary to popular belief, this driver can communicate at relatively high speeds, but it suffers from some other deficiencies too arcane to merit attention here. One way to optimize the Windows communication driver is to edit the SYSTEM.INI file in C:\WINDOWS.

solution

Type "EDIT C:\WINDOWS\SYSTEM.INI" from a DOS prompt and add the following lines to the section that begins "[386Enh]":

MinTimeslice=20

WinTimeslice=100,50

COMxFIFO=1

COMxBuffer=1024

(Instead of the letter x, you should substitute the number of the COM port to which your modem is connected, in most cases 2). You will need to restart your computer for these changes to take effect.

If modifying the SYSTEM.INI file does not solve the problem, using a third-party communications driver in place of the Microsoft communications driver would be the next logical step. Give us a call at 895-2633 and we can point you in the direction of some good alternatives to the Windows communications driver as well as assist you in installing and configuring them. Note that this solution does not apply to every Internet access package compatible with Windows 3.11. Packages that do not use the Windows communications driver in the first place do not benefit from swapping it out in favor of a third-party alternative. Netscape Navigator Personal Edition falls under this category.

It should also be noted that the ideal solution to this problem is ultimately to upgrade to Windows95 which offers a considerably more robust networking architecture.

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Currently the industry is experiencing certain difficulties with a particular kind of modem known as "RPI," an acronym for Rockwell Protocol Interface. Rockwell Inc. manufactures much of the circuitry used in the thousands of modems that are sold every year. RPI modems do not perform error correction or data compression. Instead, these features are located within software that is loaded on the computer to which the RPI modem is attached. While this approach is in theory perfectly sound, many users of RPI modems have reported problems with connecting to various online services such as America Online, Compuserve, Prodigy - and yes - Novia Internetworking.

Here at Novia we currently do not have a rock-solid recipe for successful connections with RPI modems. We do know that if own an RPI modem, it is critical that you have the most recent driver software for it, particularly if you are using Windows 3.11. Since it is possible to customize these drivers for particular modems bearing the RPI designation, you should contact your modem manufacturer for a copy of the most recent driver. Rockwell makes a generic version of the driver which we can provide to you as well. Just give us a call at 895-2633.

Making Sure YourMaking Sure Your

Home's Wiring Is Suitable for

High-Speed Communications

Because high-speed modems are particularly vulnerable to physical telephone line impurities and other wiring problems, the first step in troubleshooting any modem problem is verifying that the physical connections are as reliable as possible.

The information your computer sends and receives - whether it originates on a floppy disk, CD-ROM, or online service - is digital in nature. Digital communication is perhaps more appropriately described as binary communication, or the transmission of data entirely through the use of zeros and ones. Because ours is a universe of tens - and has been so ever since our earliest ancestors counted their fingers and toes - it is easy to forget that our most flexible creations, computers, live in a base two - not ten - world.

Satellites, cellular telephones, and fiberoptic communications are just a few of the workhorses of the digital communications revolution. However, there is one corner of the telecommunications world where the zeros and ones of binary communication cannot travel, a place known as the subscriber loop.

The subscriber loop is the pair of copper wire that connects our home telephones to the rest of the telephone network. Subscriber loops congregate in automated "switches," from which out- and in-bound calls are routed by a computer. Subscriber loops, some of which are quite ancient, were designed to convey the human voice through the transmission of analog wave forms, the electrical echoes of the vibrations we create when speaking into a telephone receiver. Since subscriber loops are built to convey this,

… while computers might represent the same information like this,

… we cannot simply run a cable from our computer to the telephone jack and join the online revolution; our computer will need some additional assistance. It will need a device to modulate its binary transmissions into analog waveforms to send data, and it will need a device to demodulate incoming analog transmissions into their original binary form to receive data. One device that performs both jobs is a modem.

Modems transmit digital information by converting it into various analog wave forms. Early modems represented the zeros and ones of digital communication by altering the amplitude of the wave form being transmitted. There were four "states" or frequencies in those bygone days, two each - representing a zero or a one - for the sending and receiving modems. While this may sound like technobabble, these early modems were essentially no more exotic than an AM radio limited to the reception of four stations, or perhaps more correctly, a two-way AM radio limited to two stations.

Of course contemporary modems have changed all that, but not as much as we might be tempted to think. The speed of a modem is a function of its throughput, a measure of the number of binary digits or bits that can be transmitted in any given second under ideal conditions. The march to contemporary high-speed modems began with a throughput of 2400 bits per second or bps, but thanks to data compression technologies, today modems can be purchased that operate at a throughput rating of 28,800 bits per second, or 28.8 kbps. The next jump appears to be 33,600 or 38,400.

Modem manufacturers have had to devise some rather ingenious methods to achieve these blistering speeds. The number of frequency changes the average telephone line can tolerate is fixed at a value appropriate to the demands of the human voice (and perhaps a little substandard for your average opera singer). Trying to pack nearly 30,000 bits of information every second into a pair of copper wire never built for anything more expansive than the demands of the human voice is a daunting task. What this means in practical terms is that high-speed modems are more prone to experience problems with the hisses, clicks and buzzes we associate with normal telephone conversations (line noise). To compensate for these impurities, modems are designed with error-correction circuitry to detect and eliminate connection problems. The V.n designation after your modem, (V.34 for example), references which form of industry-approved error correction your modem supports. Part of any good error correction scheme is the ability to lower connection speed in the event of line noise much like an airline pilot might lower altitude to avoid turbulence. Modems are somewhat schizophrenic in this regard, however, for while a part of the modem's circuitry devotes itself to compensating for line noise - to the point of dropping connection speed if deemed necessary - other components of the modem's circuitry work equally hard to speed the transmission of data by compressing it.

No Chains, Please

Many kinds of telecommunications equipment, such as answering and fax machines, support "daisy chaining" or the connection of multiple devices to one RJ-11 (standard telephone) jack. Your high speed modem should not be part of such a chain as each device along its path can result in signal degradation. Ideally, the only object between the modem and the wall jack should be three to six feet of telephone wire.

Depending on how your home or office is wired, localized physical problems may continue to plague your connectivity even if the modem is no longer a node along a string of telephone devices. While the best test of your line quality can only be performed by a trained service technician, there are some diagnostic tools at your disposal which may inform your decision to call the telephone company for an on-site wiring inspection.

The Hearing Test

When you listen to your telephone's dialtone, is it clear or muddied by the presence of a low-frequency hum? While this test seems crude, it is often the most revealing. Oftentimes hearing test impurities are a result of lengthy wiring "runs" between the modem and the "demarc," the point at which the telephone line exits your premises - usually in a basement or utility closet - and begins its journey to the nearest central office. If this internal or "premises wiring" is substandard to boot, high-speed connections will be problematic.

Having established that a noisy line exists, the next question is of course, "Why?" Does the problem originate within my home or office - or is it beyond my control? Unfortunately, these questions are more easily posed than answered.

A few years ago I lived in an apartment blessed with a spectacularly clean telephone line. There was so little noise that I was actually able to configure my modem to dial a BBS system in Boston - with my calling card. Considering the number of central offices, switches, and long-distance routing hubs between my modem in Nebraska and the destination host in Massachusetts, that was a remarkable achievement. I had never expected it to work and in my astonishment at the operation's success found myself staring in wide-eyed wonder at the lit "carrier detect" light on my modem.

Months later this same, exquisite telephone line simply went dead. No dialtone. At this particular apartment complex, the telephone wiring closet was in the laundry room and fully accessible to the tenets, as were the electrical access panels and circuit breakers. Code violations aside, it was an invitation to test the wiring pair that had suddenly abandoned me. Testing the pair in the closet failed as well, revealing that that particular wiring pair from the central office to the apartment complex had been turned off or reassigned elsewhere. Contacting the telephone company remedied the problem, but the wiring pair I received to restore service was not the one I had lost. It was considerably noisier and, needless to say, the glory days of the calling card long-distance modem connection were over. I relate this tale because it represents one of the few situations in which one can clearly determine where line noise originates. I knew empirically that the noise was a function of my line to the central office, not the internal wiring. In most such situations, however, locating the source of the problem is more challenging. One way to test your internal wiring would be to perform what I like to call the "Total Isolation Test."

The Total Isolation Test

Disconnect all telephones (cordless and otherwise), answering machines, fax machines, and other devices from the wall throughout your home or apartment, leaving only your high-speed modem connected. Connect to Novia as you normally would. Is the connection faster? More stable? If so, it is likely that you have a "noisy" fax machine or some other device whose presence along the chain is muddying your modem's transmissions. If problems persist, connect the modem to the jack at the demarcation point, the location within your home where the telephone wiring enters the premises. Once again, connect to Novia. If the problems disappear under these circumstances it is reasonable to assume that your high-speed connections are being sabotaged by poor internal wiring. Switching to a different telephone jack may eliminate or at least alleviate the problem.

Copper signal wire is identified by what is known as a "CATx" standard (CAT1, CAT2, CAT3, etc.) If the distance between your modem and the demarc is less than a hundred feet, a fresh length of CAT3 - (available just about anywhere where telephones are sold) - should do the trick. If the cable run from the modem to the demarc is greater than one hundred feet (as the cable lays), a higher-grade wiring plant is essential. CAT5 should do nicely, although it is harder to find. When troubleshooting customer connections, we usually get ours at the Graybar Electric Company (4360 S. 90th, approximately at 90th and L Streets - 592-7676).

What Do I Do If The Problems Persist?

At this point, having ruled out internal wiring as the problem, the next step would be to attempt to get a cleaner line from the nearest central office. As a general rule telephone companies are reluctant to support customers with data transmission problems and quick to point out that they are contractually obligated to provide voice communications only. However, promotional programs urging customers to add a second line for data and facsimile access are starting to change this picture. Nevertheless, you may find yourself receiving faster service if you present the problem to the phone company in its own vocabulary. A dirty line can be just as distracting to a human trying to carry on a conversation as it can to a computer trying to carry on a file transfer.