This page provides common troubleshooting solutions for the UIUCnet Premier and UIUCnet Dialup services. For frequently asked questions such as hours, phone numbers, and technical support contacts, see the FAQ page.
Dialing and connection problems
- I'm having trouble dialing in.
- I'm having trouble dialing in with a calling card or from a different location than usual.
- I'm having trouble connecting or staying connected.
Phone lines
- My modem speeds aren't as fast as they should be.
- I have a 56Kbps modem, and I only connected at 42000 (or some other lower-than-expected speed, but higher than 28.8).
- I have a 56Kbps modem and only get 28.8 (or slower) connections.
- My dialing software claims we've connected at 115,000 bps!
- How can I clean up a noisy phone line?
- The line noise isn't in my house/apartment. What can I try next?
Authentication and error messages
- I'm getting error message #691 ("The computer you're dialing in to cannot establish a dial-up networking connection" or "Access denied because username and/or password is invalid on the domain").
- I'm getting an error message that's not #691
- I changed my Net ID password, and now I can't dial in - how do I update my Net ID password? (New page)
Problems after connecting
- I'm having trouble getting Microsoft Outlook to work correctly over dialup.
- I'm having trouble getting Illinois Compass or another web-based application to work correctly over dialup.
Advanced solutions
Dialing and connection problems
I'm having trouble dialing in.
There are several points in the dialing process which can cause connection problems. Beginning at the point where the phone number is dialed, here are some of the possible points of failure:
- Phone numbers, area codes, or other dialing prefixes and suffixes
(See the Phone Numbers section of the Dialup FAQ and, if traveling, the 800 Number Configuration, Network Access for Travelers and/or Calling Cards pages.)
- User name and password information
(See the authentication section of this FAQ.)
- Line noise
(See the phone lines section of this FAQ. Note that line noise is responsible for most of the speed issues reported.)
I'm having trouble dialing in with a calling card or from a different location than usual.
If you're having problems using a calling card with your dialing string, see the Calling Cards page.
If you're having problems using the usual phone number from a different location or different area code, refer to the UIUC 800 configuration page for specific examples of how to create other locations, use area codes and dialing prefixes/suffixes, and so on.
I'm having trouble connecting or staying connected
This is probably the most frustrating problem, both for you and for the person trying to help you troubleshoot it. In most cases, people experiencing this problem are having intermittent troubles: dial four times, get kicked off 3, and the fourth time is fine. In most cases, this is just another manifestation of line noise. It is often actually related more to intermittant or bursts of line noise than to constant line noise.
If your phone has call waiting, and another call comes in when you're connected with your modem, you're likely to be disconnected. Therefore, you should tell your modem to temporarily disable call waiting when you dial in.
You can add the code *70, to the beginning of your dial string to disable call waiting while you've connected through the modem. (Make sure you include the comma after the number 70.) Even on unlisted phones, this can often solve the problem.
When modems connect, they initially negotiate a speed they can talk at. This is the squealing and hissing that most modems make after the remote modem answers. Most modems, by default, negotiate two protocols simultaneously: one controls speed, and one controls error correction. If error rates get too high, the error correction protocols force a "step down" in your connection speed. You will usually only notice this, if at all, as a short pause. Unfortunately, few modems actually implement and use a "step up." So when your connection drops 2Kbps because of errors, there it stays until you hang up.
If your connection has to step down too many times, the modems simply hang up. Rarely, if your modem steps down and the remote end doesn't get the signal, the modems are de-modulated, and they hang up.
The troubleshooting options below may help. There are three primary sources of connection problems: phone lines, connection options that produce error messages, and more advanced solutions such as protocol and modem codes.
Phone lines
My modem speeds aren't as fast as they should be
Which of the following describes your symptoms?
- I have a 56Kbps modem, and I only connected at 42000 (or some other lower-than-expected speed, but higher than 28.8).
- I have a 56Kbps modem and only get 28.8 (or slower) connections.
- My dialing software claims we've connected at 115,000 bps!
- I have a 56Kbps modem, and I only connected at 42000 (or some
other lower than expected speed, but higher than 28.8).
On perfectly noise free lines, a 56Kbps modem will not connect at above 53Kbps, due to FCC regulations about the speed of data transfer over public phone lines.
When a modem encounters noise, the 56Kbps modem protocols will step down the speed of the connection until they have a speed that they can maintain error free (after accounting for error correction protocols). Even on the cleanest of real world phone lines, connecting and maintaining 50Kbps is a rare thing. In practice, you are doing well to be getting between 42Kbps and 48Kbps.
See below for tips on how to help reduce the impact of line noise on your modem.
- I have a 56Kbps modem and only get 28.8 (or slower) connections.
Line noise is the most common condition which dictates how fast a pair of modems will connect. However, if you're consistently getting less than half your modem's theoretical maximum speed, there may also be a modem protocol or configuration issue.
Identifying line problems: You can help identify whether the problem is your phone line by taking your computer and modem to another location (preferably in another building), plugging it in, and dialing up. If you get a better connect speed, your line is the most likely factor. See below for some suggestions on how to combat line noise.
If moving to a different location doesn't help with your connection speed, you may have a problem with your modem or its configuration. One thing you can do is check your vendor's web page to see if there is a software upgrade for your modem or drivers. Additional modem interaction possibilities include analog-to-digital converters in your phone line's path, the distance being dialed, and modem communication standards.
Analog-to-digital converters: 56Kbps modem technologies are truly pushing the limits of what can be done over a single analog phone line. Because of this, all three forms of 56Kbps modem technologies require that there be only one analog-to-digital convertor [ADC] in the phone path between your modem and the server you're dialing into. If there are two or more ADCs in the phone path, then your modems will be unable to connect at 56Kbps. Unfortunately, there is almost never a solution for this.
Dialing distance: You may encounter more problems if you're dialing long or intermediate distances. The longer the distance, as measured by your phone path, the more chances that there are modem-unfriendly phone devices. For example, the path might include lots of echo cancellation gear, or just introduce enough delay into the path that the 56Kbps modem protocols give up. Dialing from one phone provider to another is usually enough to guarantee that you won't be able to get a 56Kbps connection.
Modem standards: Your 56Kbps modem may not be using the same standard as the CITES modem pool. UIUCnet Premier currently supports the V.90 standard and Kflex V1.1. For technical reasons beyond CITES' control, Kflex V1.1 is incompatible with Kflex V1.0. (Check with your modem manufacturer to see if your Kflex modem can be upgraded to v1.1 or V.90; most can!) CITES servers also do not support the USR/3com standard x2.
It is also possible that your dual-standard Kflex/V.90 modem might be having an adverse interaction while trying to negotiate the connection. Some dual-standard modems drop right down to 28.8 rather than trying to negotiate a different style of 56Kbps connection if one 56Kbps protocol fails. Your modem manual might have a setting which can control this behavior, or you can force it to select a particular protocol. (More information about forcing modems to use the V.90 protocol is available in the Advanced section.)
V.90 is the ITU approved standard, and the only one that CITES officially supports. Someday, our vendor will probably quietly remove support for Kflex.
If you have a 56K dialup modem that claims to have connected at 115,000 bps (which is approximately 112K), you've run into a marketing trick. Many modems are now factory set to return the speed of the connection between the modem and the computer, not between the modems. Check your modem manual for how to change this in your modem startup code.On a Zoom Telephonics modem, for example, you can add "ATW1" to the modem initialization string to have the modem return line speed and error control information upon connect.
How can I clean up a noisy phone line?
You can confirm that the line noise is in your residence by taking your computer to another location and dialing. If you get a better connection, the noise is most likely in your house or line to your phone company. Mind you, this isn't conclusive--the line noise could be intermittent. Also, the place you brought your computer to might also have a noise problem of its own.
Line noise can enter your phone system from a number of places.
Old or poorly done telephone wiring is a source of line noise. Each wiring, rewiring, and addition creates a new place where the wires are accepting ingress noise. Apartments are especially sensitive to this, since many residents "fix" their wiring problems themselves. Fixing this is difficult, and usually involves rewiring. You might try looking over the wiring to see if there are "obvious" faults. If you own your home, try running a new line direct from your network interface to your computer's location.
Most modems ship with the cheapest phone cord the manufacturer can put RJ-11 ends on. Those silver cords are often called "silver satin," and have terrible properties. Replace it with something better. Almost every store that carries phones carries 25 foot rolls of decent quality phone cable, as well as crimpers and ends.
Another suggestion: Don't use a cord any longer than you have to. Long cords work well for your stereo as antennas; they work equally well as antennas for line noise.
Another common source of line noise is everything else on your phone lines. Unplug your phones, answering machines, etc, and see how things work. If this doesn't help much, run a phone cord directly from the jack in your network interface to your PC. That will eliminate virtually every source of noise inside your home that you can. Obviously, this is just a test to see if you can block out line noise. But if it helps, you can install a new jack that runs direct to the network interface on a new, clean cable.
The line noise isn't in my house/apartment. What can I try next?
There's not much you can do. You could call your phone company and complain. It probably won't work, but you can try it. Phone companies are notoriously unresponsive to customer problems, and usually respond to them with a priority set based on how much money they make off you.
Ameritech has, in the past, tried to sell something called a "conditioned line" to people who complain bitterly about line quality. They charge high fees for this: a few hundred dollars for the setup, and a much higher monthly line charge. When one of CITES' network designers spoke to them about this (years ago), they also pointed out that they wouldn't guarantee any improvement at all. If you get this option, beware: it probably isn't a good deal.
Authentication and error messages
I'm getting error message #691. ("The computer you're dialing in to cannot establish a dial-up networking connection" or "Access denied because username and/or password is invalid on the domain")
There are several conditions which can cause this error:
- You may have mis-typed your Network ID or Network ID password.
Try retyping your name and password.
- You may be accidentally trying to connect to a Windows domain.
Right click on your dialup icon and select Properties. Click on the Networking tab. Make sure "Client for Microsoft Networks" is NOT selected.
- You may have used all the available hours for the week.
Check your available hours at https://www-s7.cites.uiuc.edu/termserv/myhours.cgi. If you need more hours, you can sign up for them at https://uofitelecom.cso.uiuc.edu/changeservice_WebTSO.cgi/sourcehtml/ndo/termserv/TSfacstaff_Entry.html.
- Your Network ID password may have expired, or
- Your identity may have been shut off by Security because of a virus infection on a system identified with you.
If either of these is the case, you'll need help checking your status and correcting it. Contact the CITES Help Desk at 244-7000 (toll-free 1-800-531-2531) or visit 1211 DCL between 8:30 and 5 p.m. weekdays.There are other possibilities as well. If none of these solutions resolves the problem, contact the CITES Help Desk for more assistance.
I'm getting an error message that's not #691.
There are hundreds of other error messages possible. If you're getting another error number, try looking for it on Google or one of the following modem error listing sites:
You can also contact the CITES Help Desk at 244-7000 or visit 1211 DCL between 8:30 and 5 p.m. weekdays.
Problems after connecting
I'm having trouble getting Microsoft Outlook to work correctly over dialup.
Due to ongoing attacks on the campus network through port 135 (from the Blaster worm and variants), this port is blocked from use by UIUCnet Dialup users as well as any other off-campus network connection. This will affect users of Microsoft Outlook and some other Microsoft products.
In order to use Outlook, you can either authenticate through the campus VPN system or use an Outlook web interface. In order to use port 135 for any program other than Outlook, you will need to authenticate through the campus VPN system.
I'm having trouble getting Illinois Compass or another web-based application to work correctly over dialup.
Unfortunately, many newer Internet-based applications assume that a network connection will be able to communicate at speeds faster than 56K. Parts of your network application may simply time out before they can be completed over a dialup connection. Some applications may also use Microsoft network ports which are blocked for security reasons, as described above.
In these cases, you may need to find a non-dialup way to use these applications. Campus computer labs are available at most hours during the semesters. You may also wish to investigate higher-speed network connections for your residence.
Advanced solutions
What are the modem protocols? Which control speeds, and which error corrections?
The ITU (International Telecom Union) is the standards body which approves modem protocols. Some of the protocols determine speeds, some of them determine error control methods. Without getting too detailed, here's a quick description of what some of the most common protocols and speeds are.
Protocol Possible Speeds Notes V.21 300 V.22 1200 V.22 bis 2400 or 1200 V.23 1200 V.32 9600 or 4800 V.32 bis 14400, 12000, 9600, 7200, or 4800 V.34 33600, 31200, 28800, 26400, 24000, 21600,
19200, 16800, 14400, 12000, 9600, 7200, 4800, or
2400K56flex 56000, 54000, 52000, 50000, 48000, 46000,
44000, 42000, 40000, 38000, 36000, 34000, 32000Not an ITU standard
Premier only supports Kflex v1.1x2 56000, 54666, 53333, 52000, 50666, 49333, 48000, 46666, 45333, 44000, 42666, 41333, 37333, 33333 Not an ITU standard
Not supported by any CITES dialup poolV.90 56000, 54666, 53333, 52000, 50666, 49333, 48000, 46666, 45333, 44000, 42666, 41333, 40000, 38666, 37333, 36000, 34666, 33333, 32000, 30666 ITU standard for 56Kbps connections MNP5 Error Correction protocol MNP10 Error Correction protocol V.42 bis Error Correction protocol Also refered to as LAP-M
I have a dual-mode 56Kbps modem. How can I be sure I'm using v.90?
Some dual mode modems, notably ones based on the Lucent chipsets (for example, Zoom), default to Kflex rather than V.90. In general, V.90 connections perform better than Kflex (or X2, for those of you using a provider that supports X2). You can configure your modem to prefer a V.90 connection over Kflex.
The following is information provided by Cisco:
V.90 client modems using Lucent chipsets need an additional command in order to connect to an access server in V.90 mode. The following paragraphs describe how to use the additional command to connect the modems using these chipsets to an access server.
ats109=2
If the modem responds with ERROR, the modem you are using does not contain the Lucent chipset. You may also check your modem for Lucent chipsets with this command:
ati11
A modem using a Lucent chipset will respond with output similar to the following:
ati11
Description Status --------------- ------------ Last Connection NA Initial Transmit Carrier Rate NA Initial Receive Carrier Rate NA Final Transmit Carrier Rate NA Final Receive Carrier Rate NA Protocol Negotiation Result NA Data Compression Result NA Estimated Noise Level NA Receive Signal Power Level (-dBm) NA Transmit Signal Power Level (-dBm) NA Round Trip Delay (msec) NA Near Echo Level (-dBm) NA Far Echo Level (-dBm) NA Transmit Frame Count 0 Transmit Frame Error Count 0 Receive Frame Count 0 Receive Frame Error Count 0 Retrain by Local Modem 0 Call Termination Cause 0 Robbed-Bit Signaling NA Digital Loss (dB) NA OK
Consult your modem manual for more information.
Tweaking your modem to deal with line noise.
This is a complex, time-consuming, and technical process. Please note that you should be very familar with your modem, and comfortable with making these changes, before following any of the following steps. Any of the changes you make are done at your own risk; CITES cannot bear any responsibilty for errors. Also, the steps listed below really are extreme measures.
Programming your modem is fairly easy. Open up a terminal problem (with windows 95, 98, or NT, you can run "Hyperterminal", which is included with the os). Connect to the COM port that your modem is on. Type "at", hit enter, and you should see an "OK" response. Now you can enter commands directly to your modem. Note that mode commands begin with "AT" (ATtention). For example, to actually make your modem dial, you would enter "ATDT phonenumber" and hit enter.
First thing to know: Every modem has a "reset to factory defaults" command. Usually, it's "AT&F". Make sure you know this command, because the following instructions change some deeply imbedded settings.
So, what kind of things can you do to deal with problem noise?
You can try adjusting the setting of the S10 register. On most modems, this register controls the time between carrier loss and when your modem hangs up. Every modem has a different default, but most are around 1 second. You can adjust this to be very liberal, with the setting being the number of .1-second intervals that must elapse before the modem hangs up. You might try setting this to be 2-4 seconds, by using the command "ATS10=20".
If you are only having trouble connecting, not staying connected, you might try adjusting the S9 register. The S9 register controls the length of time that a modem will wait while negotiating carrier before it finally gives up. Again, the default varies from modem to modem. If you are having trouble connecting, you might increase this value to 2-4 seconds. Remember that the setting is a number of .1-second increments.
Another way to deal with line noise would be to disable error correction. Remember that this will do strange things if an error happens when you are not using PPP. If you are using PPP, then TCP/IP will detect and correct for errored packets, to a reasonable extent. You will need to check your modem manual to determine the correct way to do this. As an example, the Zoom modem uses the value of AT%C to control this. Some manuals may list this setting as controlling compression, because the error-correcting protocols do compress data some.
Last, you can force your modem to only connect at a certain speed. If you're having trouble maintaining connections at 28.8Kbps, for example, you can configure your modem only to connect at 19.2Kbps or 14.4Kbps. This might make things smoother for you. Of course, when line conditions improve, you will have no way to detect and take advantage of them.
Originally written by Debbie Fligor, maintained by CITES Documentation
Last update: August 13, 2004
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Last modified April 17, 2007