Background Information

Before discussing the possible causes of random disconnections and slow connections, there are a few details of the mechanics of how a modem connection operates that must be established. First, modem connections initiated and controlled by the computer making the phone call. The modem answering, in this case those here at Merge, have a totally passive role in setting up a connection. All our modems do is respond to requests made by your computer. Second, because of that it is the calling modem that determines the speed of the connection. It is also the calling modem that monitors the connection, to determine when or if an adjustment of the connection speed is required.

Establishing a Connection.

When you instruct your computer to connect to Merge, here's what happens. You computer opens a program called Dialup Networking and runs a script that contains our phone number, and your user information. This program activates your modem and tells it to place a phone call. From this point on, everything else is automatic, and part of the basic function of modems. Neither nor Merge can alter this sequence. You modem dials, and waits for an answer tone from my modem. If it doesn't hear a tone, it hangs up with an error message. If it does hear a tone, it analyses that tone. If it detects any sort of irregularity - any noise on the line, or any sort of static - in that tone, it asks my modem to resend a tone, at a slightly lower frequency. When it finds a frequency that it determines is 'clean' it initiates a connection. The frequency your modem judges clean determines the speed of that connection. This whole process is called "handshaking."

Resends and Retrains.

While you are connected, your modem exchanges data with our modem. That data is checked for errors by the modem that receives it. If errors are found, a request is sent to resend that segment. If too many resend requests are generated, your modem can attempt to 'retrain' the connection. It pauses and starts another handshaking session. In rare cases this can result in the connection speed being increased, but usually its set lower. Lower speed means the sounds are sent at a lower frequency, and lower frequencies are less subject to line noise or static. Thus, 56K modem are more vulnerable to line noise then 33.6 modems, because they have the ability to hear at a higher frequency.

Slow Connections.

Slow connections, then, are most often caused by conditions on the phone line that require your modem to settle on a lower speed for a connection, or to resend and retrain frequently. This isn't always the case - sometimes the line is fine. You may or may not be able to tell, simply by picking up your phone (when you modem is not connected) and listening. If you hear *any* static or anything other then a clear dial tone, you have to assume your computer will hear it too. Anything your modem hears it attempts to interpret. If it hears static, it can't interpret it, and it will ask for a resend of that data. My modem won't have a clue what your modem is asking - it didn't send any data - and a retrain will occur. In the case that you can't hear any noise, you may have a modem that is starting to fail. It's not properly 'hearing' the signal being sent to it. In this case you should have your machine looked at by a technician.

One other common cause for "slow" connections is that 56K modems have a built in 'distance limitation.' A normal phone line can really only support data transfer at between 28,800 bps and 33,600 bps. 56K (56,000bps) modems cheat. Through a bit of technological wizardry they manage to force higher frequency connections without requiring modifications to the end users (your) phone line. To support 56K, though, your ISP (Merge) has to have digital phone lines installed. 56k modem technology requires that all the lines that your data travels along to be digital *except* for the link between you and Bell. It also requires that your modem be located no more then 5 miles from a Bell switching office. If there is an analogue 'link' between you and Bells office, or if you're too far away, then you won't get more then perhaps 33,600 connections. If that.

Disconnections.

Most disconnections occur as a result of line conditions that result in too many, or too frequent, retrains. After a few retrains your modem will usually decide that the line is bad, and disconnect hoping that a redial will get a cleaner line. All of the factors listed above contribute to disconnections. Line noise, static, multiple resends, multiple retrains, quality of the initial connection all play a part - if you get a lower speed connection then usual in the first place, it won't take many retrains for your modem to give up and want to redial.

Disconnections when using Email.

Some disconnections can be explained by how your mail program is set up. Most mail programs have an option for using it while offline. In this case, the mail program only connects to us for long enough to receive any mail you have waiting, and to send any mail you have queue up on your end. Then it terminates your dialup session. If you've been connected a while, browsing, and you open your mail program to check mail, it will do so...then terminate your connection. It doesn't matter if you are doing something else at the time, the mail program does what it's told. Also, most mail programs can also be set to check mail every few minutes, usually 10. If you have both these features turned on, you'll get disconnected every 10 minutes.

Most of our customers use Outlook Express. To see if you have it set to hang up every time it checks mail, open Outlook Express and click on Tools/Options/Connections. If there is a check mark in "Hang up after sending and receiving" click on it to turn this feature off.

Conclusions.

To wind this up, you'll note that in no case, above, do our modems initiate a disconnection of your dialup session. They can't. There isn't a signal that our modems can send to yours to ask it to hang up. To cause a disconnection from our end of the connection, the modem you are connected to must be switched off. There must be an actual interruption in the modems normal operation. Any case that would cause a modem to be reset while there is an active connection to it will be generated by our monitoring software, and will send an email to you explaining why you were disconnected. If you haven't received such an email from us, then the disconnection wasn't caused at our end of the connection.