Dial-Up Connection Problems

Line quality and the modems determine connection speeds.

Modems negotiate a error free baud rate at connection time. The bandwidth (or "bandpass") of a voice-grade phone line is about 3,000Hz to 4,000Hz (3-4KHz). Because the mathematics of compressing 33.6kbps pushes the phone line to near its theoretical limits, V.34 was designed to accommodate a variety of phone line conditions. V.FC and V.34 are both smart enough to do what is called a "channel probe", which is a frequency response and signal-to-noise ratio test of frequencies at various points across the bandpass. During the modem handshake, the modems send a series of tones to each other, at known signal levels and specific frequencies. The modem calculates the level of the received signal at each frequency, and therefore can determine the maximum bandwidth available for use.

You can find out more about V.34 modems and noise at www.swin.edu.au, Curt's High Speed Modem FAQ, or Line Noise Testing Procedures.
Three factors determine connecting at 56kbps.

Your phone line must be capable of supporting K56 speeds.

You must have a modem that matches the protocol used at the ISP. Currently there are three formats. K56Flex, X2, and V.90. The new ITU 56K modem standard is V.90 and this along with K56Flex are formats we support.
You can find out more about 56K at www.56k.com, www.k56.com, http://www.v90.com/, or http://808news.com/56k/.

A. Unexpected disconnects can plague any data communications connection. Generally, there will always be an occasional disconnect. After all, we are dealing with phone lines being pushed to the limits with V.32, V.34 and now V.90 modems. Phone lines were designed for voice, not for data transmission. If you find that you are experiencing frequent or infrequent disconnects with your connection to Internet Pathway, the following information may assist you in troubleshooting this situation.

Inactivity Timeout

Internet Pathway has a 60 minute timeout on idle connections. A 60 minute timeout means we will drop the connection after 60 minutes of there is no network activity (no packets sent or received) on your PPP connection.

While this may be obvious to many who are reading this, it's a good idea to keep in mind that "no activity" doesn't mean that you're not doing anything. You could be composing an email message, or reading a web page; it's even possible to go from one web page to another and have them all be in your local computer's memory cache. These would all equal "no activity" on your network connection to Internet Pathway and could result in a dropped connection.

One way to ensure that "no activity" is not the cause of disconnects is set keep an email client like Eudora or Netsacpe open during all sessions and set that email program to check for mail every 15 minutes.

But if you're getting a lot more than the occasional disconnect, something is wrong and you should methodically follow the steps below.

Call Waiting

If you have the call waiting feature from BellSouth, your connection can be interrupted if you receive a call while online. Disable "Call Waiting" by dialing *70, before the accces number. This disables call waiting for the duration of the call and is automatically re-enabled when you hang up. This is an option with Windows 95 dial-up networking.

Line Noise and Frequent Disconnects

Frequent disconnects may be tied to specific line problems. Even if other connections to other providers or BBS's in the area are stable, the specific connection made from your locale to ours can be problematic. These problems may be represented as occasional line bursts that drop connections, or consistent line noise that result in lost connections due to a modem's inability to deal with the line conditions. Some modem brands, such as US Robotics products, have line diagnostics that can be employed after a disconnect to determine the cause of the drop. It may be helpful to consult your manual to see if this feature is available.

A modem's ability to deal with line noise can make a world of difference. Most modems will 'train down' to slower speeds as line conditions worsen. Some 28.8 modems have been known to have a 'spiraling death' syndrome, where they are unable to 'train up' to higher speeds when conditions improve. These speed negotiation may be transparent to the user of the modem. At best, the user may simply notice that speeds become slower and slower as time goes by. Frequent disconnects after similar periods of time (i.e. every five minutes or so) can be symptoms of this problem. Contact your modem manufacterer to obtain the latest version of software (or 'firmware' in most cases) for your modem. Many manufacterer's ship these upgrades for free.

Line Noise and Infrequent Disconnects

Infrequent disconnects may reflect a temporary change in your connection. Weather conditions can cause temporary changes in line conditions. Besides the obvious physical damage due to fallen tress, etc., studies have shown that excessive rain can cause increased line noise. Physical work, like construction or new line installation, can cause Bell South to temporary reroute line paths, perhaps through a noisier switch. Lowering your baud rate temporarily may allow your modem to 'weather' these changes in line condition changes.

Line Noise and Lowering Speed

Lowering your baud can accomplish a few things with regard to line noise. A lower rate can force your modem to switch to a different protocol (i.e. 19200 will force a 28.8K modem to use the v.32 protocol which does not renegotiate line speeds except in extreme conditions.) Secondly, slower speeds much less succeptable to line noise. In the "old days" when 2400 was screaming fast and there was no error correction, line noise was a huge problem. The common solution was to slow down to 1200, because the protocol was more than half as succeptable to line noise. Nowadays we have error correction, and don't "see" the line noise, but the same solution applies. 19.2K may be slower than what your modem is capable of, but if using a slower speed allows you to maintain connections during times of noisy phone ciruits, then it is, ultimately, much faster.

Line Noise and your Phone Service Provider

Finally, if you feel that your phone line is unusually noisy all of the time, you may wish to investigate it with your phone provider. They do have a responsibility to provide phone connections within certain specifications, and it is possible that a line test will show that yours falls outside of those specs.