The actual connection speed will fluctuate. If the call route has only one Analog to Digital conversion you will obtain an x2 connection which may range from 33333 to 53333. This connection speed varies because there is an Analog portion of a 56K connection. As mentioned in the connection speed section, error correction was developed to resolve performance problems with modem connections. Without error correction your modem would never connect or frequently disconnect.
Error correction allows the modem speed to lower or increase based on current line conditions.
This means the modem has the built in software to perform error correction. Connection problems usually center around three things, these three items can adversely affect one another. Therefore a noisy phone line problem can be magnified if you are using an inexpensive modem, but can be decreased if you have a high end modem with the latest updates. If any of the three are unreliable your connection will be affected. Verify you have the help guide for your software package to rule out software problems.